Description

DBCO-TFP ester, product number QBD-11815, is the 2,3,5,6-tetrafluorophenyl (TFP) ester of an aza-dibenzocyclooctyne (DBCO) product used for strain-promoted azide-alkyne cycloaddition (SPAAC, also known as “”copper free click chemistry””). The TFP ester reacts selectively and efficiently with amines to form amide bonds. TFP esters are preferred over N-hydroxysuccinimide (NHS) esters because they are more stable to hydrolysis and react more efficiently with amines than NHS esters. The DBCO moiety reacts selectively with azides via SPAAC to form stable triazole linkages. Insoluble in water, DBCO-TFP ester is slightly soluble to sparingly soluble in most organic solvents. Vector Laboratories recommends dimethylsulfoxide (DMSO), N,N’-dimethylformamide (DMF), or N,N’-dimethylacetamide (DMAC) as solvents for this product. DBCO-TFP ester is acid sensitive. It should not be subjected to pH <5 during reaction or workup.

The published discovery in 2004 of SPAAC, also known as “”copper free click chemistry,”” by Carolyn Bertozzi and coworkers improved the click chemistry toolbox. Toxic copper catalysts were eliminated, making the reaction truly bioorthogonal. By removing the copper(I) catalyst from the reaction, living cells can be labeled with reagents designed for SPAAC. Since the original publication, multiple improvements in strained cyclooctyne reagents resulted in the development of DBCO as a nearly perfect azide partner for SPAAC.

To use DBCO-TFP ester in aqueous media or in cells, it should be conjugated to a water-soluble dPEG® product. Vector Laboratories offers numerous products for this purpose, including amino alcohols and amino acids. We also offer many ready-to-use DBCO-functionalized dPEG® products.

Specifications

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.

Description

DBCO-acid, product number QBD-11814, is an aza-dibenzocyclooctyne (DBCO) product used for strain-promoted azide-alkyne cycloaddition (SPAAC, also known as “”copper free click chemistry””). The DBCO moiety reacts selectively with azides via SPAAC to form stable triazole linkages. Esterification of the terminal carboxylic acid with N-hydroxysuccinimide (NHS) or 2,3,5,6-tetrafluorophenol (TFP) allows for reaction with a primary amine. Insoluble in water, DBCO-acid is slightly soluble to sparingly soluble in most organic solvents. Vector Laboratories recommends dimethylsulfoxide (DMSO), N,N’-dimethylformamide (DMF), or N,N’-dimethylacetamide (DMAC) as solvents for this product. DBCO-acid is relatively insensitive to bases and can be used in the presence of aqueous bases. This product is acid sensitive and should not be subjected to pH <5 during reaction or workup.

The published discovery in 2004 of SPAAC, also known as “”copper free click chemistry,”” by Carolyn Bertozzi and coworkers improved the click chemistry toolbox. Toxic copper catalysts were eliminated, making the reaction truly bioorthogonal. By removing the copper(I) catalyst from the reaction, living cells can be labeled with reagents designed for SPAAC. Since the original publication, multiple improvements in strained cyclooctyne reagents resulted in the development of DBCO as a nearly perfect azide partner for SPAAC.

To use DBCO-acid in aqueous media or in cells, it should be conjugated to a water-soluble dPEG® product. Vector Laboratories offers numerous products for this purpose, including amino alcohols and amino acids. We also offer many DBCO-based dPEG® products already prepared for use.

Specifications

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.

Description

DBCO-amine, product number QBD-11750, is an aza-dibenzocyclooctyne (DBCO) product used for strain-promoted azide-alkyne cycloaddition (SPAAC, also known as “”copper free click chemistry””). The DBCO moiety reacts selectively with azides via SPAAC to form stable triazole linkages. The amine terminus of the molecule reacts with carboxylic acids and their active esters to form stable amide bonds. Insoluble in water, DBCO-amine is slightly soluble to sparingly soluble in most organic solvents. Vector Laboratories recommends dimethylsulfoxide (DMSO), N,N’-dimethylformamide (DMF), or N,N’-dimethylacetamide (DMAC) as solvents for this product. DBCO-amine is relatively insensitive to bases and can be used in the presence of aqueous bases. This product is acid sensitive. It should not be subjected to pH <5 during reaction or workup. The product should always be stored at -20°C when not in use.

The published discovery in 2004 of SPAAC, also known as “”copper free click chemistry,”” by Carolyn Bertozzi and coworkers improved the click chemistry toolbox. Toxic copper catalysts were eliminated, making the reaction truly bioorthogonal. By removing the copper(I) catalyst from the reaction, living cells can be labeled with reagents designed for SPAAC. Since the original publication, multiple improvements in strained cyclooctyne reagents resulted in the development of DBCO as a nearly perfect azide partner for SPAAC.

To use DBCO-amine effectively in aqueous media or in cells, it should be conjugated to a water-soluble dPEG® product. Vector Laboratories offers numerous products for this purpose, including hydroxy acids (and their active esters), and protected amino acids. We also offer many DBCO-based dPEG® products already prepared for use.

Specifications

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.

Description

Tetra(-amido-dPEG®11-MAL)pentaerythritol, product number QBD-11435, is a maleimide-functionalized PEG crosslinking reagent designed to join up to four molecules via a maleimide-thiol reaction. Each of the four arms of this product comes from a single molecular weight, discrete polyethylene glycol (dPEG®) spacer that is 43 atoms (47.4 Å) long, joined through a pentaerythritol core. Product applications include (1) crosslinking of proteins, peptides, or small molecules containing free sulfhydryl groups and (2) dendrimer construction with thiol-functionalized branched compounds.

The thiol-maleimide reaction, also known as the thiol-Michael addition, is a click chemistry reaction. This powerful, highly popular reaction is extensively used in bioconjugation applications. At pH 6.5 – 7.5, the thiol-maleimide reaction is chemoselective. However, above pH 7.5, the maleimide group reacts competitively with amines, so the pH should be kept below this limit.

Unlike traditional polyethylene glycol (PEG), which are non-uniform, dispersed polymers, Vector Laboratories’ dPEG® products are single molecular weight PEGs with discrete chain lengths, hence the dPEG® name.

Tetra(-amido-dPEG®11-MAL)pentaerythritol showcases one of the benefits of dPEG® linkers in product development. Each of the four dPEG® arms is identical, and the uniformity simplifies analysis. In contrast, if this product were made using traditional, non-uniform PEG compounds, analyzing it would be much more complicated and challenging.

Specifications

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.

Description

Bromoacetamido-dPEG®12-Tris(-dPEG®11-amido-bromoacetamide)3, product number QBD-11434, is a branched, single molecular weight, thiol-reactive, discrete polyethylene glycol (dPEG®) product. It is designed to join up to four molecules via a thiol-bromoacetyl reaction. Each of the four arms attaches to a central tris core and terminates with a thiol-reactive bromoacetyl group. The dPEG® spacer length from between the bromoacetyl groups through the tris core is 87 atoms (100.0 Å).

Like the thiol-maleimide reaction, the thiol-bromoacetyl reaction forms stable thioether bonds with free thiols. However, maleimides react optimally at pH 6.5 – 7.5, while bromoacetyl groups react with thiols chemoselectively at pH ≥8.0. Moreover, thioether bonds formed from a thiol-maleimide reaction can sometimes undergo a reverse Michael addition, undoing the thioether bond. This does not happen with thioether bonds formed by a thiol-bromoacetyl reaction. The thiol-bromoacetyl reaction is chemoselective for thiols but slightly less selective than the thiol-maleimide reaction.

Unlike traditional polyethylene glycol (PEG), which are non-uniform, dispersed polymers, Vector Laboratories’ dPEG® products are single molecular weight PEGs with discrete chain lengths, hence the dPEG® name. The four arms of MAL-dPEG®12-Tris(-dPEG®11-amido-MAL)3 are built around a core of tris(hydroxymethyl)aminomethane (“”tris””). Although one arm is structured a little differently than the other three arms (one dPEG®12 arm vs. three dPEG®11 arms), the product is essentially symmetrical through the tris core. This precise construction of Bromoacetamido-dPEG®12-Tris(-dPEG®11-amido-bromoacetamide)3 is possible because of Vector Laboratories’ dPEG® technology. This product can link multiple peptides or proteins together for drug delivery. It could also be used as a core unit for constructing dendrimers with precisely defined spacer lengths.

Specifications

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.

Description

MAL-dPEG®12-Tris(-dPEG®11-amido-MAL)3, product number QBD-11433, is a branched, single molecular weight, thiol-reactive, discrete polyethylene glycol (dPEG®) product. It is designed to join up to four molecules via a maleimide-thiol reaction. Built around a tris core and terminated on each arm with a thiol-reactive maleimide group, this homotetrafunctional crosslinker is 96 atoms long (124.4 Å) from one maleimide to another.

The thiol-maleimide reaction, also known as the thiol-Michael addition, is a click chemistry reaction. This powerful, highly popular reaction is extensively used in bioconjugation applications. At pH 6.5 – 7.5, the thiol-maleimide reaction is chemoselective. However, above pH 7.5, the maleimide group reacts competitively with amines, so the pH should be kept below this limit.

Unlike traditional polyethylene glycol (PEG), which are non-uniform, dispersed polymers, Vector Laboratories’ dPEG® products are single molecular weight PEGs with discrete chain lengths, hence the dPEG® name. The four arms of MAL-dPEG®12-Tris(-dPEG®11-amido-MAL)3 are built around a core of tris(hydroxymethyl)aminomethane (“”tris””). Although one arm is differently structured than the other three arms (one dPEG®12 arm vs. three dPEG®11 arms), each arm has the same number of atoms and the same length when measured from the reactive site on the maleimide to the tris core from which each arm branches. This precise construction occurs because the dPEG® spacers have discrete chain lengths. This product can link multiple peptides or proteins together for drug delivery. It could also be used as a core unit for constructing dendrimers with precisely defined spacer lengths.

Specifications

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.

Description

Tetra(-amido-dPEG®23-MAL)pentaerythritol, product number QBD-11414, is a maleimide-functionalized PEG crosslinking reagent designed to join up to four molecules via a maleimide-thiol reaction. Each of the four arms of this product comes from a single molecular weight, discrete polyethylene glycol (dPEG®) spacer that is 79 atoms (89.8 Å) long, joined through a pentaerythritol core. Product applications include (1) crosslinking of proteins, peptides, or small molecules containing free sulfhydryl groups and (2) dendrimer construction with thiol-functionalized branched compounds.

The thiol-maleimide reaction, also known as the thiol-Michael addition, is a click chemistry reaction. This powerful, highly popular reaction is extensively used in bioconjugation applications. At pH 6.5 – 7.5, the thiol-maleimide reaction is chemoselective. However, above pH 7.5, the maleimide group reacts competitively with amines, so the pH should be kept below this limit.

Unlike traditional polyethylene glycol (PEG), which are non-uniform, dispersed polymers, Vector Laboratories’ dPEG® products are single molecular weight PEGs with discrete chain lengths, hence the dPEG® name.

Tetra(-amido-dPEG®23-MAL)pentaerythritol showcases one of the benefits of dPEG® linkers in product development. Each of the four dPEG® arms is identical, and the uniformity simplifies analysis. In contrast, if this product were made using traditional, non-uniform PEG compounds, analyzing it would be much more complicated and challenging.

Specifications

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.

Description

MAL-dPEG®24-amido-dPEG24-amido-dPEG®24-DSPE, product number QBD-11388, is designed to facilitate payload delivery in liposomes and micelles. The long (234 atoms, 275.8 Å), single molecular weight, discrete-chain-length polyethylene glycol (dPEG®) spacer is conjugated to 1, 2-Distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) for liposomal or micellar insertion and functionalized with a sulfhydryl-reactive maleimidopropyl moiety that forms thioether bonds with a payload (e.g., a targeting peptide or cytotoxin) containing a free thiol group. The free maleimide group may also facilitate cellular uptake of liposomes or micelles containing the moiety through thiol-mediated membrane trafficking.

Unlike traditional polymer PEG products, which consist of an intractable mixture of different chain lengths and molecular weights of PEG and have an irreproducible purity profile, Vector Laboratories dPEG® products are high purity single molecules containing one PEG chain length and molecular weight with a reproducible purity profile.

Specifications

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.

Description

Biotin-dPEG®4-amido-dPEG®24-amido-dPEG®24-DSPE, product number QBD-11386, permits biotin labeling of liposomes and micelles by attaching a biotin label to the lipid 1,2-Distearoyl-SN-glycero-3-phosphoethanolamine (DSPE) through a very long (169 atoms, 186.3 Å) single molecular weight, discrete chain length PEG (dPEG®) spacer. The dPEG® spacer has a mass comparable to the polymer PEG2000 commonly used in liposomes and micelles, but unlike polymer PEG, which consists of a diverse and intractable mixture of PEG chain lengths and molecular weights, the dPEG® spacer is a high-purity, single molecule product. The non-immunogenic dPEG® spacer increases the hydrodynamic volume of the molecule, improving its water solubility. In liposomes and micelles, the conjugate’s increased hydrodynamic volume may help hide the carrier construct from the immune system and prevent opsonization.

The biotin label of QBD-11386, biotin-dPEG®4-amido-dPEG®24-amido-dPEG®24-DSPE can be used in therapeutic antibody pretargeting to improve radioimmunotherapy in liposomal and micellar carriers and reduce off-target effects. In addition, the product can be mixed with other DSPE products from Quanta BioDesign with different reactive, protective, or functional groups.

Specifications

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.

Description

Carboxyfluorescein-dPEG®24-amido-dPEG®24-DSPE, product number QBD-11385, consists of the lipid 1,2-Distearoyl-SN-glycero-3-phosphoethanolamine (DSPE) conjugated to a long (152 atoms, 180.0 Å), single molecular weight, discrete polyethylene glycol (dPEG®) spacer that has been functionalized with 5(6)-carboxyfluorescein. The dPEG® spacer consists of two dPEG®24 linkers joined by an amide bond, making the spacer effectively a dPEG®48 product with a molecular weight of slightly more than 2,000 Daltons (i.e., equivalent to a PEG2000). The product is designed for use in liposomes and micelles where a fluorescent dye label is needed. The carboxyfluorescein dye has an absorbance maximum (λex) of 497 nm and an emission maximum (λem) of 524 nm, with an extinction coefficient of 63303 M-1 cm-1 at 497 nm, and an A280 correction factor of 0.18.

Liposomes and micelles are often coated with traditional, polymeric PEG2000 (a polymer PEG having an average molecular weight of 2,000 Daltons) at a density of about 5 – 8 mole%. A polymer PEG2000 consists of an intractable mixture of different chain lengths and molecular weights of PEG, making analysis difficult. Unlike a traditional, non-uniform (that is, dispersed) PEG2000, QBD-11385, carboxyfluorescein-dPEG®24-amido-dPEG®24-DSPE is a single, uniform product. Carboxyfluorescein-dPEG®24-amido-dPEG®24-DSPE is designed to provide a convenient dye label for liposomes, micelles, and other lipid nanoparticles. This allows labeled liposomes and micelles to be tracked over time.

Specifications

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.