- Amine Pegylation
- Carboxyl Pegylation
- Gold SurfacePegylation
- Hydroxyl Pegylation
- Thiol Pegylation
- N-terminal pegylation
PEG-hydrazide can pegylate carboxyl group quite selectively in presence of N,N'-dicyclohexylcarbodiimide (DCC), or in presence of a water soluble coupling agent such as N-(-3dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC).
The very low pKa (~3) of the hydrazide group allows carboxyl pegylation in acidic media in presence of EDC. The carboxyl groups of a protein which are readily activated with EDC at mild acidic pH, tend to react readily with PEG-hydrazide, whereas amino groups of the protein remain non-active.
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2. Rubinstein, M., Simon, S., Bloch, R., US Patent 4,101,380 (1978)
3. Davis, F.F., Van Es, T., Palczuk, N.C., US Patent 4,179,337 (1979)
4. Shimizu, K., Nakahara, T., Kinoshita, T., US Patent 4,495,285 (1985)
5. Persson, S., Olde, B., J. Chromatogr., 1988, 457, 183-193.
6. Zalipisky S. and Menon-Rudolph, S., Polyethylene Glycol, pp318-341, Chapter 21.
Hydrazide derivatives of polyethylene glycol and their bioconjugates, 1997 American Chemical Society.