Identification of cysteinylation of a free cysteine in the Fab region of a recombinant monoclonal IgG1 antibody using Lys-C limited proteolysis coupled with LC/MS analysis.

@article{Gadgil2006IdentificationOC,
  title={Identification of cysteinylation of a free cysteine in the Fab region of a recombinant monoclonal IgG1 antibody using Lys-C limited proteolysis coupled with LC/MS analysis.},
  author={Himanshu S. Gadgil and Pavel V. Bondarenko and Gary D. Pipes and Thomas M. Dillon and Douglas Banks and Jeffrey S. Abel and Gerd R. Kleemann and Michael J. Treuheit},
  journal={Analytical biochemistry},
  year={2006},
  volume={355 2},
  pages={165-74}
}
MAB007, an IgG1 monoclonal antibody, is unique because of the presence of a free cysteine residue in the Fab region at position 104 on the heavy chain in the CDR3 region. Mass spectrometric analysis of intact MAB007 showed multiple peaks varying in mass by 120-140 Da that cannot be fully attributed to glycosylation isoforms typically present in IgG molecules. Limited proteolysis of MAB007 with Lys-C led to a single cleavage at the C-terminus of a lysine residue in the hinge region of the heavy… CONTINUE READING