Analytical Methods to Characterize and Quantify PEG and PEGylated Biopharmaceuticals

摘要

Biotherapeutic peptides and proteins are often PEGylated(cova-lently bonded to polyethylene glycol polymers)to improve bioavailability, reduce immunogenicity, and extend circulating half-life(1). Achieving the desired properties for each application depends on optimizing the number and site of polymers attached, chain length, and the degree of chain branching. This is accomplished by careful choice of PEGylation reagents and reaction conditions. For example, the Thermo Scientific MS(PEG)_n series consists of N-hydroxysuc-cinimide(NHS)esters that react at pH 7-9 with primary amine groups. The molar ratio of reagent-to-protein should be optimized for each application.