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-dPEG®24-TFP ester, product number QBD-11370, is a heterobifunctional, bioorthogonal crosslinker designed to join azides and amines across a long (76 atoms, 88.8 Å), flexible, hydrophilic, single molecular weight, discrete PEG (dPEG®) spacer. The tetrafluorophenyl (TFP) ester reacts specifically with free amines to form amide bonds; the optimum reaction pH is 7.5 – 8.0. The dibenzylcyclooctyne (DBCO) moiety selectively forms triazole linkages with azides via a click chemistry reaction known as strain-promoted azide-alkyne cycloaddition (SPAAC), also known as copper-free click chemistry. The amphiphilic dPEG® linker increases conjugates’ hydrodynamic volumes, and it can be used to create space in sterically crowded supramolecular constructs.

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-dPEG®12-TFP ester, product number QBD-11366, is a heterobifunctional, bioorthogonal crosslinker designed to join azides and amines across a medium-length (40 atoms, 46.3 Å), flexible, hydrophilic, single molecular weight, discrete PEG (dPEG®) spacer. The tetrafluorophenyl (TFP) ester reacts specifically with free amines to form amide bonds; the optimum reaction pH is 7.5 – 8.0. The dibenzylcyclooctyne (DBCO) moiety selectively forms triazole linkages with azides via a click chemistry reaction known as strain-promoted azide-alkyne cycloaddition (SPAAC), also known as copper-free click chemistry. The amphiphilic dPEG® linker increases conjugates’ hydrodynamic volumes, and it can be used to create space in sterically crowded supramolecular constructs.

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-dPEG®4-TFP ester, product number QBD-11362, is a heterobifunctional, bioorthogonal crosslinker designed to join azides and amines across a short (16 atoms, 17.9 Å), flexible, hydrophilic, single molecular weight, discrete PEG (dPEG®) spacer. The tetrafluorophenyl (TFP) ester reacts specifically with free amines to form amide bonds; the optimum reaction pH is 7.5 – 8.0. The dibenzylcyclooctyne (DBCO) moiety selectively forms triazole linkages with azides via a click chemistry reaction known as strain-promoted azide-alkyne cycloaddition (SPAAC), also known as copper-free click chemistry. The amphiphilic dPEG® linker increases conjugates’ hydrodynamic volumes, and it can be used to create space in sterically crowded supramolecular constructs.

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-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

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.

Description

Bromoacetamido-dPEG®24-TFP ester, product number QBD-11203, is a long (78 atoms, 91.2 Å), single molecular weight, discrete PEG (dPEG®) crosslinker functionalized with a thiol-reactive bromoacetate group on one end and an amine-reactive 2,3,5,6-tetrafluorophenyl (TFP) ester on the other.

The long, flexible, non-immunogenic dPEG® crosslinker increases the hydrodynamic volumes of conjugates in aqueous media, thereby increasing water solubility. The increased hydrodynamic volume can reduce or eliminate conjugate molecules’ renal clearance and shield conjugates from opsonization.

The bromoacetate moiety is an alternative to the maleimide group, reacting chemoselectively with free thiols at pH ≥8.0. It is useful for situations where the conjugate molecule needs to be kept at a high pH, above the range where maleimides can be used effectively, or in constructs where maleimide groups are unstable.

TFP esters are an alternate reactive group to the N-hydroxysuccinimidyl (NHS) ester and reacts with amines at an optimal pH range of 7.5 – 8.0, higher than the optimal range for NHS esters (pH 7.0 – 7.5). TFP esters are more hydrolytically stable than NHS esters, and they are more reactive toward amines in their optimal pH range than NHS esters are within the pH range 7.0 – 7.5.

Specifications

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.

Description

Bromoacetamido-dPEG®12-TFP ester, product number QBD-11202, is a medium-length (42 atoms, 48.7 Å), single molecular weight, discrete PEG (dPEG®) crosslinker functionalized with a thiol-reactive bromoacetate group on one end and an amine-reactive 2,3,5,6-tetrafluorophenyl (TFP) ester on the other.

The medium-length, flexible, non-immunogenic dPEG® crosslinker increases the hydrodynamic volumes of conjugates in aqueous media, thereby increasing water solubility. The increased hydrodynamic volume can reduce or eliminate conjugate molecules’ renal clearance and shield conjugates from opsonization.

The bromoacetate moiety is an alternative to the maleimide group, reacting chemoselectively with free thiols at pH ≥8.0. It is useful for situations where the conjugate molecule needs to be kept at a high pH (≥8.0), above the range where maleimides can be used effectively, or in constructs where maleimide groups are unstable.

TFP esters are an alternate reactive group to the N-hydroxysuccinimidyl (NHS) ester and reacts with amines at an optimal pH range of 7.5 – 8.0, higher than the optimal range for NHS esters (pH 7.0 – 7.5). TFP esters are more hydrolytically stable than NHS esters, and they are more reactive toward amines in their optimal pH range than NHS esters are within the pH range 7.0 – 7.5.

Specifications

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.

Description

Bromoacetamido-dPEG®4-TFP ester, product number QBD-11200, is a short (18 atoms, 20.4 Å), single molecular weight, discrete PEG (dPEG®) crosslinker functionalized with a thiol-reactive bromoacetate group on one end and an amine-reactive 2,3,5,6-tetrafluorophenyl (TFP) ester on the other.

The short, flexible, non-immunogenic dPEG® crosslinker increases the hydrodynamic volumes of conjugates in aqueous media, thereby increasing water solubility. The increased hydrodynamic volume can reduce or eliminate conjugate molecules’ renal clearance and shield conjugates from opsonization.

The bromoacetate moiety is an alternative to the maleimide group, reacting chemoselectively with free thiols at pH ≥8.0. It is useful for situations where the conjugate molecule needs to be kept at a high pH (≥8.0), above the range where maleimides can be used effectively, or in constructs where maleimide groups are unstable.

TFP esters are an alternate reactive group to N-hydroxysuccinimidyl (NHS) esters and react with amines at an optimal pH range of 7.5 – 8.0, higher than the optimal range for NHS esters (pH 7.0 – 7.5). TFP esters are more hydrolytically stable than NHS esters, and they are more reactive toward amines in their optimal pH range than NHS esters are within the pH range 7.0 – 7.5.

Specifications

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.

Description

Fmoc-N-amido-dPEG®36-TFP ester, product number QBD-11008 contains an Fmoc-protected amine on one end of a long (112 atoms), single molecular weight, discrete-chain-length polyethylene glycol (dPEG®) spacer and the tetrafluorophenyl (TFP) ester of a propionic acid group on the other end. This product is ready for the direct introduction of a water-soluble, amphiphilic spacer into a peptide chain. The Fmoc protecting group on the N-terminus of the molecule cleaves easily with standard peptide chemistry.

Fmoc-N-amido-dPEG®36-TFP ester permits our customers to insert a dPEG® spacer into a peptide chain using standard Fmoc chemistry without the need to activate the acid terminus for conjugation. The product works in solid-phase and solution-phase synthetic processes; however, it may work better in solution-phase syntheses because of the dPEG® spacer’s length. In aqueous solutions, TFP esters are more hydrolytically stable than NHS esters and have an optimum pH range of 7.5 – 8.0 for conjugation. The dPEG® linker attaches at the N-terminal end of the peptide chain or on the free amine side chain of amino acids such as lysine. Additional peptide synthesis can be carried out to extend the peptide further, creating a peptide with a flexible, hydrophilic linker or spacer in the middle or joining two different peptides across the dPEG® bridge. In addition, the dPEG® chain can provide spacing in a synthetic construct where steric hindrance is a problem. Amphiphilic, non-immunogenic dPEG® increases the hydrodynamic volume and improves the water solubility of the conjugate while remaining soluble in organic solvents. The Fmoc protecting group is removed easily with a solution of piperidine in N,N-dimethylformamide (DMF).

Specifications

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.

Description

Fmoc-N-amido-dPEG®24-TFP ester, product number QBD-11007 contains an Fmoc-protected amine on one end of a long (76 atoms), single molecular weight, discrete-chain-length polyethylene glycol (dPEG®) spacer and the tetrafluorophenyl (TFP) ester of a propionic acid group on the other end. This product is ready for the direct introduction of a water-soluble, amphiphilic spacer into a peptide chain. The Fmoc protecting group on the N-terminus of the molecule cleaves easily with standard peptide chemistry.

Fmoc-N-amido-dPEG®24-TFP ester permits our customers to insert a dPEG® spacer into a peptide chain using standard Fmoc chemistry without the need to activate the acid terminus for conjugation. The product works equally well in solid-phase and solution-phase synthetic processes. In aqueous solutions, TFP esters are more hydrolytically stable than NHS esters and have an optimum pH range of 7.5 – 8.0 for conjugation. The dPEG® linker attaches at the N-terminal end of the peptide chain or on the free amine side chain of amino acids such as lysine. Additional peptide synthesis can be carried out to extend the peptide further, creating a peptide with a flexible, hydrophilic linker or spacer in the middle or joining two different peptides across the dPEG® bridge. In addition, the dPEG® chain can provide spacing in a synthetic construct where steric hindrance is a problem. Amphiphilic, non-immunogenic dPEG® increases the hydrodynamic volume and improves the water solubility of the conjugate while remaining soluble in organic solvents. The Fmoc protecting group is removed easily with a solution of piperidine in N,N-dimethylformamide (DMF).

Specifications

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.