Analysis of recombinant monoclonal antibody isoforms by electrospray ionization mass spectrometry as a strategy for streamlining characterization of recombinant monoclonal antibody charge heterogeneity

摘要

A therapeutic recombinant monoclonal antibody analyzed by cation-exchange chromatography exhibited a heterogeneous profile composed of approximately 10 isoforms. The peaks were isolated and characterized by electrospray quadrupole time-of-flight mass spectrometry (ESI-q-TOF-MS), N-terminal Edman sequencing, peptide mapping, and other techniques. Acidic (lower pI) peaks were found to represent deamidated and sialyated species. Higher pI peaks were found to contain N- and C-terminal heavy-chain variants. Biological activities of the more abundant isoforms were found to be comparable. An approach streamlining the characterization of antibody charge heterogeneity is proposed. (c) 2005 Elsevier Inc. All rights reserved.