Maleimide – VectorLabs https://staging.vectorlabs.com From linker design and synthesis, bioconjugated design and manufacturing, biomolecule labeling and functionalization, and detection system and solutions, our team is here to help you move forward, with impact. Wed, 22 Oct 2025 17:21:10 +0000 en-US hourly 1 https://wordpress.org/?v=6.9 https://staging.vectorlabs.com/wp-content/uploads/2024/11/V-favicon-02-100x100.png Maleimide – VectorLabs https://staging.vectorlabs.com 32 32 MAL-dPEG®₂₄-amido-dPEG®₂₄-TFP ester https://staging.vectorlabs.com/products/mal-dpeg24-amido-dpeg24-tfp-ester/ Sat, 24 Feb 2024 02:16:36 +0000 https://staging.vectorlabs.com/?post_type=product&p=39378 MAL-dPEG®24-amido-dPEG®24-TFP ester, product number QBD-11303, is a monodisperse, crosslinking PEGylation reagent that joins sulfhydryl groups to amines through a long (158 atoms, 183.5 Å), single molecular weight, discrete PEG (dPEG®) chain. One end of the crosslinker is functionalized with a maleimidopropyl (maleimide) group for reaction with free thiols, and the other end has the 2,3,5,6-tetrafluorophenyl (TFP) ester of propionic acid for reaction with free amines. The dPEG® linker consists of two dPEG®24 chains joined by an amide bond, making it functionally a dPEG®48 crosslinker with a molecular weight that is slightly more than 2000 Daltons. At pH 6.5 – 7.5, the maleimide group reacts specifically with sulfhydryl (thiol) groups to form a thioether bond. The TFP ester reacts with free amines to form amide bonds at an optimum reaction pH range of 7.5 - 8.0.

Crosslinking free thiols to free amines is one of the most popular and most useful reactions in bioconjugate chemistry. These reactions require heterobifunctional reagents that bridge the two groups. Typical, traditional crosslinkers are short and hydrophobic and frequently trigger aggregation and precipitation of conjugates made from them. In addition, traditional PEG crosslinkers use non-uniform (dispersed) polymer PEGs that consist of an intractable mixture of PEG chain lengths and molecular weights. The complexity arising from non-uniform PEG crosslinkers makes analyzing conjugates a challenging exercise.

In contrast, Vector Laboratories' dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. Our dPEG® products are uniform in chain length and molecular weight (Ð = 1). This uniformity of our dPEG® products eliminates one of the most vexing analytical difficulties faced by users of traditional polymer PEG products.

Specifications

Unit Size 100 mg, 1000 mg
Molecular Weight 2573.87; single compound
Chemical formula C₁₁₅H₂₀₉F₄N₃O₅₄
CAS N/A
Purity > 97%
Spacers dPEG® Spacer is 158 atoms and 183.5 Å
Shipping Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene Chloride, DMSO, DMAC, DMF, Acetonitrile or Chloroform.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₂₄-amido-dPEG®₂₄-TFP ester appeared first on VectorLabs.

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Description

MAL-dPEG®24-amido-dPEG®24-TFP ester, product number QBD-11303, is a monodisperse, crosslinking PEGylation reagent that joins sulfhydryl groups to amines through a long (158 atoms, 183.5 Å), single molecular weight, discrete PEG (dPEG®) chain. One end of the crosslinker is functionalized with a maleimidopropyl (maleimide) group for reaction with free thiols, and the other end has the 2,3,5,6-tetrafluorophenyl (TFP) ester of propionic acid for reaction with free amines. The dPEG® linker consists of two dPEG®24 chains joined by an amide bond, making it functionally a dPEG®48 crosslinker with a molecular weight that is slightly more than 2000 Daltons. At pH 6.5 – 7.5, the maleimide group reacts specifically with sulfhydryl (thiol) groups to form a thioether bond. The TFP ester reacts with free amines to form amide bonds at an optimum reaction pH range of 7.5 – 8.0.

Crosslinking free thiols to free amines is one of the most popular and most useful reactions in bioconjugate chemistry. These reactions require heterobifunctional reagents that bridge the two groups. Typical, traditional crosslinkers are short and hydrophobic and frequently trigger aggregation and precipitation of conjugates made from them. In addition, traditional PEG crosslinkers use non-uniform (dispersed) polymer PEGs that consist of an intractable mixture of PEG chain lengths and molecular weights. The complexity arising from non-uniform PEG crosslinkers makes analyzing conjugates a challenging exercise.

In contrast, Vector Laboratories’ dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. Our dPEG® products are uniform in chain length and molecular weight (Ð = 1). This uniformity of our dPEG® products eliminates one of the most vexing analytical difficulties faced by users of traditional polymer PEG products.

Specifications

Unit Size100 mg, 1000 mg
Molecular Weight2573.87; single compound
Chemical formulaC₁₁₅H₂₀₉F₄N₃O₅₄
CASN/A
Purity> 97%
SpacersdPEG® Spacer is 158 atoms and 183.5 Å
ShippingAmbient
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, DMSO, DMAC, DMF, Acetonitrile or Chloroform.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

The post MAL-dPEG®₂₄-amido-dPEG®₂₄-TFP ester appeared first on VectorLabs.

]]> MAL-dPEG®₃₆-NHS ester https://staging.vectorlabs.com/products/mal-dpeg36-nhs-ester/ Sat, 24 Feb 2024 02:13:41 +0000 https://staging.vectorlabs.com/?post_type=product&p=37122 MAL-dPEG®36-NHS ester, product number QBD-10904, is a crosslinking reagent that joins a sulfhydryl to a free amine through a hydrophilic bridge. The sulfhydryl groups react with a maleimide group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the N-hydroxysuccinimidyl (NHS) ester of a carboxylic acid group. The maleimide and NHS functional groups on the crosslinking compound sit at either end of a long (118 atoms, 134.8 Å), discrete-length polyethylene glycol (dPEG®) chain.

Reactions that join free amines with free thiols are among the most popular, most useful crosslinking reactions in bioconjugate chemistry. These reactions require heterobifunctional reagents that bridge the two groups. Traditional crosslinkers are hydrophobic molecules. Vector Laboratories' dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths.

The conjugation of conventional hydrophobic crosslinking reagents to biomolecules almost inevitably triggers problems such as aggregation and precipitation of the conjugates. These problems do not occur with our water-soluble, non-immunogenic dPEG® crosslinkers.

Because NHS esters hydrolyze readily in water or aqueous buffer, the NHS ester end of the molecule must conjugate to a target molecule before conjugating the maleimide end of the molecule. At pH 7.0 – 7.5, NHS esters react optimally with free amines. However, NHS esters can react with free amines with pH as low as 6.5. As the pH increases, the hydrolysis rate of the NHS ester increases. Indeed, at pH 8 and 25°C, the half-life of an NHS ester in aqueous media is one hour, while at pH 8.6 and 4°C, the half-life falls to ten (10) minutes.[3] Thus, we strongly discourage storing MAL-dPEG®36-NHS ester, product number QBD-10904, in water or aqueous buffer. Instead, we recommend that customers make new solutions of the product as needed, use them immediately, and discard unused solutions after use.

The reaction of the maleimide end of MAL-dPEG®36-NHS ester with a sulfhydryl proceeds optimally at pH 6.5 – 7.5. Use the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which can cause confusing results. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

The use of MAL-dPEG®36-NHS ester, product number QBD-10904, has been published in numerous scientific paper and patents. The following list highlights some of the more interesting uses of this product:
development of extracellular drug conjugates (EDCs), a type of ADC for extracellular markers;
targeted delivery of cancer drugs;
as a long, flexible tether for atomic force microscopy (AFM); and
as a surface coating for amine-functionalized nanoparticle surfaces.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 1923.18; single compound
Chemical formula C₈₆H₁₅₉N₃O₄₃
CAS N/A
Purity > 95%
Spacers dPEG® Spacer is 118 atoms and 134.8 Å
Shipping Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene chloride, DMAC or DMSO or Acetonitrile.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₃₆-NHS ester appeared first on VectorLabs.

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Description

MAL-dPEG®36-NHS ester, product number QBD-10904, is a crosslinking reagent that joins a sulfhydryl to a free amine through a hydrophilic bridge. The sulfhydryl groups react with a maleimide group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the N-hydroxysuccinimidyl (NHS) ester of a carboxylic acid group. The maleimide and NHS functional groups on the crosslinking compound sit at either end of a long (118 atoms, 134.8 Å), discrete-length polyethylene glycol (dPEG®) chain.

Reactions that join free amines with free thiols are among the most popular, most useful crosslinking reactions in bioconjugate chemistry. These reactions require heterobifunctional reagents that bridge the two groups. Traditional crosslinkers are hydrophobic molecules. Vector Laboratories’ dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths.

The conjugation of conventional hydrophobic crosslinking reagents to biomolecules almost inevitably triggers problems such as aggregation and precipitation of the conjugates. These problems do not occur with our water-soluble, non-immunogenic dPEG® crosslinkers.

Because NHS esters hydrolyze readily in water or aqueous buffer, the NHS ester end of the molecule must conjugate to a target molecule before conjugating the maleimide end of the molecule. At pH 7.0 – 7.5, NHS esters react optimally with free amines. However, NHS esters can react with free amines with pH as low as 6.5. As the pH increases, the hydrolysis rate of the NHS ester increases. Indeed, at pH 8 and 25°C, the half-life of an NHS ester in aqueous media is one hour, while at pH 8.6 and 4°C, the half-life falls to ten (10) minutes.[3] Thus, we strongly discourage storing MAL-dPEG®36-NHS ester, product number QBD-10904, in water or aqueous buffer. Instead, we recommend that customers make new solutions of the product as needed, use them immediately, and discard unused solutions after use.

The reaction of the maleimide end of MAL-dPEG®36-NHS ester with a sulfhydryl proceeds optimally at pH 6.5 – 7.5. Use the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which can cause confusing results. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

The use of MAL-dPEG®36-NHS ester, product number QBD-10904, has been published in numerous scientific paper and patents. The following list highlights some of the more interesting uses of this product:
development of extracellular drug conjugates (EDCs), a type of ADC for extracellular markers;
targeted delivery of cancer drugs;
as a long, flexible tether for atomic force microscopy (AFM); and
as a surface coating for amine-functionalized nanoparticle surfaces.

Specifications

Unit Size100mg, 1000mg
Molecular Weight1923.18; single compound
Chemical formulaC₈₆H₁₅₉N₃O₄₃
CASN/A
Purity> 95%
SpacersdPEG® Spacer is 118 atoms and 134.8 Å
ShippingAmbient
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, DMAC or DMSO or Acetonitrile.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0); See pp. 276-335 for general description and use of heterobifunctional crosslinkers, as well as his specific discussion with protocols of our MAL-dPEG®x-NHS esters on pp. 718-722.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

The post MAL-dPEG®₃₆-NHS ester appeared first on VectorLabs.

]]> MAL-dPEG®₁₁-Lipoamide https://staging.vectorlabs.com/products/mal-dpeg11-lipoamide/ Sat, 24 Feb 2024 02:13:22 +0000 https://staging.vectorlabs.com/?post_type=product&p=36986 MAL-dPEG®11-Lipoamide, product number 10819, is a heterobifunctional crosslinker functionalized with a maleimidopropyl group and a lipoic acid moiety on opposite ends of a medium-length (49 atoms, 59.3 Å), single molecular weight, discrete PEG (dPEG®) crosslinker. The lipoic acid moiety forms dative bonds with gold, silver, and other metals and can be used to coat or passivate metal surfaces. The maleimide group forms stable thioether bonds with free thiols and can be used to immobilize a sulfhydryl-containing biomolecule such as a peptide or antibody fragment to a metal surface through the dPEG®-lipoamide linkage. The flexible, non-immunogenic, hydrophilic dPEG® linker adds water solubility and increases the conjugate's hydrodynamic volume.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 884.11; single compound
Chemical formula C₃₉H₆₉N₃O₁₅S₂
CAS 1334172-73-4
Purity > 97%
Spacers dPEG® Spacer is 49 atoms and 59.3 Å
Shipping Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene chloride, DMAC or DMSO.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₁₁-Lipoamide appeared first on VectorLabs.

]]>

Description

MAL-dPEG®11-Lipoamide, product number QBD-10819, is a heterobifunctional crosslinker functionalized with a maleimidopropyl group and a lipoic acid moiety on opposite ends of a medium-length (49 atoms, 59.3 Å), single molecular weight, discrete PEG (dPEG®) crosslinker. The lipoic acid moiety forms dative bonds with gold, silver, and other metals and can be used to coat or passivate metal surfaces. The maleimide group forms stable thioether bonds with free thiols and can be used to immobilize a sulfhydryl-containing biomolecule such as a peptide or antibody fragment to a metal surface through the dPEG®-lipoamide linkage. The flexible, non-immunogenic, hydrophilic dPEG® linker adds water solubility and increases the conjugate’s hydrodynamic volume.

Specifications

Unit Size100mg, 1000mg
Molecular Weight884.11; single compound
Chemical formulaC₃₉H₆₉N₃O₁₅S₂
CAS1334172-73-4
Purity> 97%
SpacersdPEG® Spacer is 49 atoms and 59.3 Å
ShippingAmbient
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, DMAC or DMSO.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0), pp. 188-190, 458-497, 924-935.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Focal adhesion regulation through microcontact printing of protein nanoparticles on self-assembled monolayers for cell guidance. Albert Martinez Moreno. DUGiDocs. 2016, June 1, 2016. DOI: http://hdl.handle.net/10256/12960.

The post MAL-dPEG®₁₁-Lipoamide appeared first on VectorLabs.

]]> MAL-dPEG®₃-Lipoamide https://staging.vectorlabs.com/products/mal-dpeg3-lipoamide/ Sat, 24 Feb 2024 02:13:20 +0000 https://staging.vectorlabs.com/?post_type=product&p=36949 MAL-dPEG®3-Lipoamide, product number 10817, is a heterobifunctional crosslinker functionalized with a maleimidopropyl group and a lipoic acid moiety on opposite ends of a short (27 atoms, 31.1 Å), single molecular weight, discrete PEG (dPEG®) crosslinker. The lipoic acid moiety forms dative bonds with gold, silver, and other metals and can be used to coat or passivate metal surfaces. The maleimide group forms stable thioether bonds with free thiols and can be used to immobilize a sulfhydryl-containing biomolecule such as a peptide or antibody fragment to a metal surface through the dPEG®-lipoamide linkage. The flexible, non-immunogenic, hydrophilic dPEG® linker adds water solubility and increases the conjugate's hydrodynamic volume.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 559.74; single compound
Chemical formula C₂₅H₄₁N₃O₇S₂
CAS 1334172-72-3
Purity > 98%
Spacers dPEG® Spacer is 27 atoms and 31.1 Å
Shipping Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene chloride, DMA or DMSO. Limited solubility in acetonitrile.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₃-Lipoamide appeared first on VectorLabs.

]]>

Description

MAL-dPEG®3-Lipoamide, product number 10817, is a heterobifunctional crosslinker functionalized with a maleimidopropyl group and a lipoic acid moiety on opposite ends of a short (27 atoms, 31.1 Å), single molecular weight, discrete PEG (dPEG®) crosslinker. The lipoic acid moiety forms dative bonds with gold, silver, and other metals and can be used to coat or passivate metal surfaces. The maleimide group forms stable thioether bonds with free thiols and can be used to immobilize a sulfhydryl-containing biomolecule such as a peptide or antibody fragment to a metal surface through the dPEG®-lipoamide linkage. The flexible, non-immunogenic, hydrophilic dPEG® linker adds water solubility and increases the conjugate’s hydrodynamic volume.

Specifications

Unit Size100mg, 1000mg
Molecular Weight559.74; single compound
Chemical formulaC₂₅H₄₁N₃O₇S₂
CAS1334172-72-3
Purity> 98%
SpacersdPEG® Spacer is 27 atoms and 31.1 Å
ShippingAmbient
Typical solubility properties (for additional information contact Customer Support)Methylene chloride, DMA or DMSO. Limited solubility in acetonitrile.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0), pp. 188-190, 458-497, 924-935.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Focal adhesion regulation through microcontact printing of protein nanoparticles on self-assembled monolayers for cell guidance. Albert Martinez Moreno. DUGiDocs. 2016, June 1, 2016. DOI: http://hdl.handle.net/10256/12960.

The post MAL-dPEG®₃-Lipoamide appeared first on VectorLabs.

]]> MAL-dPEG®₆-TFP ester https://staging.vectorlabs.com/products/mal-dpeg6-tfp-ester/ Sat, 24 Feb 2024 02:11:40 +0000 https://staging.vectorlabs.com/?post_type=product&p=36500 MAL-dPEG®6-TFP ester, product number QBD-10556, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a medium-length (28 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.

The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories' dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®6-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®6-TFP ester, product number QBD-10556, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®6-TFP ester, product number QBD-10556, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 652.59; single compound
Chemical formula C₂₈H₃₆F₄N₂O₁₁
CAS
N/A
Purity > 98%
Spacers
dPEG® Spacer is 28 atoms and 32.100 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene Chloride, Acetonitrile, Methanol, Ethyl Acetate, or Water
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₆-TFP ester appeared first on VectorLabs.

]]>

Description

MAL-dPEG®6-TFP ester, product number QBD-10556, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a medium-length (28 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.

The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories’ dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®6-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®6-TFP ester, product number QBD-10556, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®6-TFP ester, product number QBD-10556, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size100mg, 1000mg
Molecular Weight652.59; single compound
Chemical formulaC₂₈H₃₆F₄N₂O₁₁
CAS
N/A
Purity> 98%
Spacers
dPEG® Spacer is 28 atoms and 32.100 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, Acetonitrile, Methanol, Ethyl Acetate, or Water
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds for pegylation applications.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See chapter 18, Discrete PEG Reagents, pp.787-821, for a full overview of the dPEG® products.

The post MAL-dPEG®₆-TFP ester appeared first on VectorLabs.

]]> MAL-dPEG®₂₄-TFP ester https://staging.vectorlabs.com/products/mal-dpeg24-tfp-ester/ Sat, 24 Feb 2024 02:11:39 +0000 https://staging.vectorlabs.com/?post_type=product&p=36472 MAL-dPEG®24-TFP ester, product number QBD-10554, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a long (87 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.

The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories' dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®24-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®24-TFP ester, product number QBD-10554, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®24-TFP ester, product number QBD-10554, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 1445.53; single compound
Chemical formula C₆₄H₁₀₈F₄N₂O₂₉
CAS
N/A
Purity > 98%
Spacers
dPEG® Spacer is 87 atoms and 92.6 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene Chloride, DMSO, DMAC or Acetonitrile.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₂₄-TFP ester appeared first on VectorLabs.

]]>

Description

MAL-dPEG®24-TFP ester, product number QBD-10554, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a long (87 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.

The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories’ dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®24-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®24-TFP ester, product number QBD-10554, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®24-TFP ester, product number QBD-10554, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size100mg, 1000mg
Molecular Weight1445.53; single compound
Chemical formulaC₆₄H₁₀₈F₄N₂O₂₉
CAS
N/A
Purity> 98%
Spacers
dPEG® Spacer is 87 atoms and 92.6 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, DMSO, DMAC or Acetonitrile.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

The post MAL-dPEG®₂₄-TFP ester appeared first on VectorLabs.

]]> MAL-dPEG®₃₆-TFP ester https://staging.vectorlabs.com/products/mal-dpeg36-tfp-ester/ Sat, 24 Feb 2024 02:11:39 +0000 https://staging.vectorlabs.com/?post_type=product&p=36480 MAL-dPEG®36-TFP ester, product number QBD-10555, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a long (117 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.
The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories' dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®36-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®36-TFP ester, product number QBD-10555, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®36-TFP ester, product number QBD-10555, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 1974.16; single compound
Chemical formula C₈₈H₁₅₆F₄N₂O₄₁
CAS
N/A
Purity > 98%
Spacers
dPEG® Spacer is 117 atoms and 139.7 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene Chloride, Acetonitrile, Acetone or DMF.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₃₆-TFP ester appeared first on VectorLabs.

]]>

Description

MAL-dPEG®36-TFP ester, product number QBD-10555, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a long (117 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.
The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories’ dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®36-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®36-TFP ester, product number QBD-10555, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®36-TFP ester, product number QBD-10555, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size100mg, 1000mg
Molecular Weight1974.16; single compound
Chemical formulaC₈₈H₁₅₆F₄N₂O₄₁
CAS
N/A
Purity> 98%
Spacers
dPEG® Spacer is 117 atoms and 139.7 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, Acetonitrile, Acetone or DMF.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

The post MAL-dPEG®₃₆-TFP ester appeared first on VectorLabs.

]]> MAL-dPEG®₈-TFP ester https://staging.vectorlabs.com/products/mal-dpeg8-tfp-ester/ Sat, 24 Feb 2024 02:11:37 +0000 https://staging.vectorlabs.com/?post_type=product&p=36455 MAL-dPEG®8-TFP ester, product number QBD-10552, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a medium-length (38 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.

The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories' dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®8-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®8-TFP ester, product number QBD-10552, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®8-TFP ester, product number QBD-10552, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 564.48; single compound
Chemical formula C₃₂H₄₄F₄ N₂O₁₃
CAS
N/A
Purity > 98%
Spacers
dPEG® Spacer is 22 atoms and 24.1 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene Chloride, DMAC, DMSO or Acetonitrile.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₈-TFP ester appeared first on VectorLabs.

]]>

Description

MAL-dPEG®8-TFP ester, product number QBD-10552, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a medium-length (38 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.

The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories’ dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®8-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®8-TFP ester, product number QBD-10552, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®8-TFP ester, product number QBD-10552, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size100mg, 1000mg
Molecular Weight564.48; single compound
Chemical formulaC₃₂H₄₄F₄ N₂O₁₃
CAS
N/A
Purity> 98%
Spacers
dPEG® Spacer is 22 atoms and 24.1 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, DMAC, DMSO or Acetonitrile.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

An Investigation of Phosphorous-Based Bioconjugation Techniques for Protein Modification. Maja Lopandic. UWSPACE. 2022. April 7, 2022. http://hdl.handle.net/10012/18138.

The post MAL-dPEG®₈-TFP ester appeared first on VectorLabs.

]]> MAL-dPEG®₁₂-TFP ester https://staging.vectorlabs.com/products/mal-dpeg12-tfp-ester/ Sat, 24 Feb 2024 02:11:37 +0000 https://staging.vectorlabs.com/?post_type=product&p=36463 MAL-dPEG®12-TFP ester, product number QBD-10553, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a medium-length (49 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.

The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories' dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®12-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®12-TFP ester, product number QBD-10553, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®12-TFP ester, product number QBD-10553, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 916.90; single compound
Chemical formula C₄₀H₆₀F₄N₂O₁₇
CAS
N/A
Purity > 98%
Spacers
dPEG® Spacer is 49 atoms and 51.1 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene Chloride, DMAC, DMSO or Acetonitrile.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₁₂-TFP ester appeared first on VectorLabs.

]]>

Description

MAL-dPEG®12-TFP ester, product number QBD-10553, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a medium-length (49 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.

The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories’ dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®12-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®12-TFP ester, product number QBD-10553, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®12-TFP ester, product number QBD-10553, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size100mg, 1000mg
Molecular Weight916.90; single compound
Chemical formulaC₄₀H₆₀F₄N₂O₁₇
CAS
N/A
Purity> 98%
Spacers
dPEG® Spacer is 49 atoms and 51.1 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, DMAC, DMSO or Acetonitrile.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

The post MAL-dPEG®₁₂-TFP ester appeared first on VectorLabs.

]]> MAL-dPEG®₄-TFP ester https://staging.vectorlabs.com/products/mal-dpeg4-tfp-ester/ Sat, 24 Feb 2024 02:11:36 +0000 https://staging.vectorlabs.com/?post_type=product&p=36447 MAL-dPEG®4-TFP ester, product number QBD-10551, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a short (22 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.
The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories' dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®4-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®4-TFP ester, product number QBD-10551, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®4-TFP ester, product number QBD-10551, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size 100mg, 1000mg
Molecular Weight 564.48; single compound
Chemical formula C₂₄H₂₈F₄N₂O₉
CAS
N/A
Purity > 98%
Spacers
dPEG® Spacer is 22 atoms and 24.1 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support) Methylene Chloride, DMSO, DMAC or Acetonitrile.
Storage and handling -20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.

The post MAL-dPEG®₄-TFP ester appeared first on VectorLabs.

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Description

MAL-dPEG®4-TFP ester, product number QBD-10551, is a crosslinking reagent that joins free amines to free thiols (sulfhydryl groups) across a short (22 atoms), single molecular weight, discrete PEG (dPEG®) linker. The sulfhydryl groups react with a maleimido group via a Michael addition reaction. The amines form amide bonds with the crosslinker by nucleophilic substitution of the 2,3,5,6-tetrafluorophenyl (TFP) ester of the terminal propionic acid group.
The conjugation of free amines to free thiols is one of the most popular, most useful crosslinking reactions in bioconjugate chemistry is the conjugation of free amines to free thiols. These reactions require heterobifunctional reagents that bridge the two groups. Typical crosslinkers are hydrophobic. Vector Laboratories’ dPEG® crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths. These hydrophilic, non-immunogenic, dPEG® crosslinkers prevent the problems with aggregation that arise when using traditional, hydrophobic crosslinkers.

Published studies have shown that TFP esters are more hydrolytically stable in aqueous buffers than N-hydroxysuccinimidyl (NHS) esters and are more reactive toward free amines. TFP esters react under the same conditions as NHS esters. However, the optimal pH range for TFP esters (7.5 – 8.0) is slightly higher than for NHS esters (7.0 – 7.5). Amide bond formation between the TFP-activated propionic acid group of MAL-dPEG®4-TFP ester and a free amine will be slightly slower at a suboptimal pH compared to the reaction rate within the optimum pH range.

The maleimide end of MAL-dPEG®4-TFP ester, product number QBD-10551, reacts optimally with a sulfhydryl at pH 6.5 – 7.5. Conduct the conjugation at the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which may confound the data. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

MAL-dPEG®4-TFP ester, product number QBD-10551, can be used the same way and in the same applications as the equivalent NHS esters. Possible uses for this product include the following:
Coating nanoparticle surfaces;
Tethering antibodies to atomic force microscopy (AFM) probes;
Constructing antibody-drug conjugates (ADCs);
Adding flexibility and water solubility to a peptide;
Increasing the water solubility and hydrodynamic volume of hydrophobic biomolecules;
Building supramolecular constructs; and,
Conjugating the TFP ester end of the molecule a liposomal surface and then using the free maleimide end of the molecule to attach a small molecule drug, peptide, or antibody for targeted delivery of a diagnostic or therapeutic package.

Specifications

Unit Size100mg, 1000mg
Molecular Weight564.48; single compound
Chemical formulaC₂₄H₂₈F₄N₂O₉
CAS
N/A
Purity> 98%
Spacers
dPEG® Spacer is 22 atoms and 24.1 Å
Shipping
Ambient
Typical solubility properties (for additional information contact Customer Support)Methylene Chloride, DMSO, DMAC or Acetonitrile.
Storage and handling-20°C; Always let come to room temperature before opening; be careful to limit exposure to moisture and restore under an inert atmosphere; stock solutions can be prepared with dry solvent and kept for several days (freeze when not in use). dPEG® pegylation compounds are generally hygroscopic and should be treated as such. This will be less noticeable with liquids, but the solids will become tacky and difficult to manipulate, if care is not taken to minimize air exposure.



Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

An Investigation of Phosphorous-Based Bioconjugation Techniques for Protein Modification. Maja Lopandic. UWSPACE. 2022. April 7, 2022. http://hdl.handle.net/10012/18138.

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