Amino-dPEG®₁₂-t-boc-hydrazide

Amino-dPEG®12-t-boc hydrazide, product number QBD-10958, is a useful molecular modification and bioconjugation reagent consisting of a free, primary amine on one end of a medium-length (45 atoms, 50.1 Å) single molecular weight, discrete-chain-length polyethylene glycol (dPEG®) linker and a Boc-protected hydrazide group on the other end. The free amine reacts with carboxylic acids and their active esters to form a stable amide bond. Following the removal of the Boc protecting group, the hydrazide can be reacted with an aldehyde (for example, formed from periodate oxidation of carbohydrates) at pH 5 – 7 to form a hydrazone bond. Hydrazone bonds are acid labile but otherwise stable, thus allowing the conjugate or supramolecular construct to degrade under acidic conditions such as in lysosomes or the acidic extracellular microenvironments at inflammation or tumor metastasis sites. The single molecular weight, discrete PEG (dPEG®) crossbridge is water-soluble and non-immunogenic, and it adds flexibility and increases the hydrodynamic volume of conjugates and supramolecular constructs that incorporate it.