Preparation and Characterization of Poly(ethylene glycol) ylated Human Growth Hormone Antagonist

摘要

In order to prepare long-lasting human growth hormone antagonist (GHA), the protein was conjugated with polyethylene glycol (PEG) to increase its molecular size. Following conjugation, the preparation was fractionated to select the optimal molecule for biological assessment. The molecules were characterized to assist in defining the molecules as drug substances for the purpose of receivign approval for clinical studies and eventually approval as therapeutic drugs. Tryptic peptide analysis was found to be an extremely useful tool to identify the PEGylation sites. Analysis revealed the pattern of PEGylation as well as the consistency of PEGylation from lot to lot. The optimal molecules were found to be between 40-50,000 kD in molecular mass. the results obtaiend by tryptic analysis were confirmed by MALDITOF mass spectrometry. In all cases, the PEGylated proteins were active with a sustained half-life.