title: Arginine modifications by methylglyoxal: discovery in a recombinant monoclonal antibody and contribution to acidic species.
abstract: Heterogeneity is common among protein therapeutics. For example, the so-called acidic species (charge variants) are typically observed when recombinant monoclonal antibodies (mAbs) are analyzed by weak-cation exchange chromatography (WCX). Several protein post-translational modifications have been established as contributors but still cannot completely account for all heterogeneity. As reported herein, an unexpected modification by methylglyoxal (MGO) was identified, for the first time, in a recombinant monoclonal antibody expressed in Chinese hamster ovary (CHO) cells. Modifications of arginine residues by methylglyoxal lead to two adducts (dihydroxyimidazolidine and hydroimidazolone) with increases of molecular weights of 72 and 54 Da, respectively. In addition, the modification by methylglyoxal causes the antibody to elute earlier in the weak cation exchange chromatogram. Consequently, the extent to which an antibody was modified at multiple sites corresponds to the degree of shift in elution time. Furthermore, cell culture parameters also affected the extent of modifications by methylglyoxal, a highly reactive metabolite that can be generated from glucose or lipids or other metabolic pathways. Our findings again highlight the impact that cell culture conditions can have on the product quality of recombinant protein pharmaceuticals.
authors.affiliation: Protein Analytics, Process Sciences Department and ‡Cell Culture, Manufacturing Sciences Department, AbbVie Bioresearch Center , Worcester, Massachusetts 01605, United States.
authors.forename: Chris
authors.initials: C
authors.lastname: Chumsae
authors.forename: Kathreen
authors.initials: K
authors.lastname: Gifford
authors.forename: Wei
authors.initials: W
authors.lastname: Lian
authors.forename: Hongcheng
authors.initials: H
authors.lastname: Liu
authors.forename: Czeslaw H
authors.initials: CH
authors.lastname: Radziejewski
authors.forename: Zhaohui Sunny
authors.initials: ZS
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D017920:Antiporters / Q000737:chemistry; D001120:Arginine / Q000737:chemistry*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D013058:Mass Spectrometry / Q000379:methods; D011765:Pyruvaldehyde / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D000911:Antibodies, Monoclonal; D017920:Antiporters; D011994:Recombinant Proteins; D011765:Pyruvaldehyde; D001120:Arginine