Investigation of the correlation between charge and glycosylation of IgG1 variants by liquid chromatography-mass spectrometry

作者：Yang Jia Ming; Ai Junwen; Bao Yuemei; Yuan Zhijun; Qin Yumin; Xie Yi Wu; Tao Desheng; Fu Daotian; Peng Yucai^*

来源：ANALYTICAL BIOCHEMISTRY, 2014, 448: 82-91.

DOI：10.1016/j.ab.2013.11.020

• Monoclonal antibody
• UPLC-MS
• Charge heterogeneity
• Glycosylation

A recombinant IgG1 monoclonal antibody (mAb) showed multiple charge variants in a cation exchange chromatography profile. To better understand the correlation between charge heterogeneity and glycosylation, a rapid reversed phase ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) method with integrated mass analysis has been developed for simultaneous determination of N-terminal pyroglutamate, C-terminal lysine truncation, and Fc glycosylation. The results show that various degrees and/or types of N-terminal pyroglutamate formation and C-terminal lysine (Lys) cleavage account for the majority of charge heterogeneity; and the charge variants showed Fc glycosylation patterns in relation to their terminal modifications. The amount of G1F decreased in the basic variants, whereas Man5 and G0F-GN increased. The complement-dependent cytotoxicity (CDC) activity of purified charge variants also suggested the potential impact of the charge differences on the glycosylation profile.