DBCO-dPEG®₄-MAL

DBCO-dPEG®4-MAL, product number QBD-10592, is a short, single molecular weight, discrete polyethylene glycol (dPEG®) crosslinking reagent. The dibenzylcyclooctyne (DBCO) moiety permits strain-promoted azide-alkyne cycloaddition (SPAAC), also known as “”copper-free click chemistry.”” The maleimidopropyl (MAL) functional group forms a thiol-ether linkage with sulfhydryl groups. The short, single molecular weight dPEG® spacer is hydrophilic and non-immunogenic. DBCO-dPEG®4-MAL provides the benefits of PEG (increased water solubility, non-immunogenicity) without the analytical headaches of PEG dispersity.

The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) discovered by K. Barry Sharpless and coworkers is one of the best-known click chemistry reactions, but its in vivo usability is limited by copper toxicity. Carolyn Bertozzi and coworkers developed SPAAC as a way to avoid copper’s toxic effects on living cells using a highly strained cyclooctyne. Developments since the initial publication show that reagents based on DBCO provide excellent, highly selective reactivity with azides, forming a triazole product.

Maleimide groups are widely popular for their ability to react rapidly with sulfhydryl groups via a Michael addition to form thioether bonds.

Vector Laboratories’ dPEG® products clearly differ from traditional polymeric polyethylene glycol (PEG). Traditional PEG is a dispersed polymer product with a Poisson distribution of chain lengths and molecular weights. The intractable mixture of chain lengths and molecular weights in traditional PEG products creates significant analytical challenges. In contrast, Vector Laboratories’ dPEG® products are single molecular weight compounds with discrete chain lengths. Using Vector Laboratories’ products greatly simplifies the analysis of dPEG®-conjugated compounds.