Carboxy-PEG4-sulfonic acid linker contains a carboxylic acid and sulfonic acid functional group. While the terminal carboxylic acid can undergo amide coupling reactions with primary amines in the presence of EDC, DCC and HATU, etc., the fulfonic acid can undergo esterification and halogen replacement reactions. The PEG spacer increases the aqueous solubilityof the resulting molecules.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.