Characterization and identification of alanine to serine sequence variants in an IgG4 monoclonal antibody produced in mammalian cell lines
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- 作者：Jinmei Fu ; jinmei.fu@bms.com ; Jacob Bongers ; Li Tao ; Dan Huang ; Richard Ludwig ; Yunping Huang ; Yueming Qian ; Jonathan Basch ; Joel Goldstein ; Ramji Krishnan ; Li You ; Zheng Jian Li ; Reb J. Russell
- 关键词：CID ; collision induced dissociation ; DTT ; dithiothreitol ; EIC ; extracted ion chromatogram ; EPCB ; end of production cell bank ; FTMS ; Fourier transform mass spectrometry ; HPLC ; high performance liquid chromatography ; IAM ; iodoactamide ; LC/MS ; liquid chromat
- 刊名：Journal of Chromatography B, Analytical Technologies in the Biomedical and Life Sciences
- 出版年：2012
- 出版时间：1 November, 2012
- 年：2012
- 卷：908
- 期：Complete
- 页码：1-8
- 全文大小：980 K
文摘
Low levels of alanine to serine sequence variants were identified in an IgG4 monoclonal antibody by ultra/high performance liquid chromatography and tandem mass spectrometry. The levels of the identified sequence variants A183S and A152S, both in the light chain, have been determined to be 7.8-9.9 % and 0.5-0.6 % , by extracted ion currents of the tryptic peptides L16 and L14, respectively. The A183S variant was confirmed through tryptic map spiking experiments using synthetic peptide, SDYEK, which incorporated Ser at the position of native Ala in the tryptic peptide L16. Both mutations were also observed by endoproteinase Asp-N peptide mapping. The variant level of A183S was also quantified by LC-UV with detection at 280 nm and fluorescence detection of tyrosine residues on the tryptic peptides. The results from LC-MS, UV, and fluorescence detection are in close agreement with each other. The levels of the sequence variants are comparable among the antibody samples manufactured at different scales as well as locations, indicating that the variants¡¯ levels are not affected by manufacture scale or locations. DNA sequencing of the master cell bank revealed the presence of mixed bases at position 183 encoding both wild and mutated populations, whereas bases encoding the minor sequence variant at position 152 were not detected. The root cause for A152S mutation is not yet clearly understood at this moment.