Correlations between in vitro potency of polyethylene glycol-protein conjugates and their chromatographic behavior.

Pegylation is the most widely used and accepted methodology for half-life extension of biopharmaceutical drugs that also improves physicochemical and biological characteristics of proteins considerably. Most of the positive pharmacological effects of pegylated proteins are believed to be related to an increased hydrodynamic volume and molecular size. To explore the size impact of polyethylene glycol (PEG) on in vitro potency, a series of well-defined conjugates of interferon alpha-2b (IFN) were prepared with PEGs of different lengths and shapes specifically attached to the N-terminal amino group of the protein.