Investigation of Differential Methionine and Trytophan Oxidation in Antibody Complementarity Determining Region Sequences

摘要

Experiments were performed on a fully-human recombinant monoclonal IgG antibody produced in CHO cells. This antibody has methionine and trytophan residues in complementarity determining region (CDR) sequences of both light and heavy chains. Differential oxidation of these residues was observed when the antibody was produced using CHO cells. These results could be mimicked using forced oxidation with various peroxide and free-radical generators, providing the ability to investigate oxidation states in a controlled manner. Characterization of oxidation pathways was obtained using a combination of reduced intact and peptide map mass spectrometry methods. These methods were correlated to orthogonal assays that showed an impact to the surface hydrophobicity of the molecule and its ability to bind to its antigen.