Aldehyde PEG is an amine reactive PEG derivative that can be used to modify biomolecules via available amine groups. The reaction between aldehyde group with ε-amine of lysine residues and the α-amine at the N-terminus produces an intermediate Schiff base. Further reduction with hydride will form a stable C-N bond. PEG aldehydes react with amine groups at a pH of from 5.5 to 9.5. Higher pH will result in multiple Pegylation with both terminal and lysine groups. Aldehyde PEG is a commonly used PEG reagent for n-terminus pegylation in proteins or peptides.
