Abstract:
:The C-terminal lysine variation is commonly observed in biopharmaceutical monoclonal antibodies. This modification can be important since it is found to be sensitive to the production process. The methods commonly used to probe this charge variation, including IEF, cIEF, ion-exchange chromatography, and LC-MS, were evaluated for their ability to effectively approximate relative percentages of lysine variants. A monoclonal antibody produced in a B cell hybridoma versus a CHO cell transfectoma was examined and it was determined that the relative amount of incorporated C-terminal lysine can vary greatly between these two production schemes. Another case study is shown whereby a different monoclonal antibody is subject to some minor process changes and the extent of lysine variation also exhibits a significant difference. During these studies the different methods for determining the extent of variation were evaluated and it was determined that LC-MS after trypsin digestion provides reproducible relative percentage information and has significant advantages over other methods. The final section of this work investigates the possible origins of this modification and evidence is shown that carboxypeptidase B or another basic carboxypeptidase causes this variation.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Dick LW Jr,Qiu D,Mahon D,Adamo M,Cheng KCdoi
10.1002/bit.21855subject
Has Abstractpub_date
2008-08-15 00:00:00pages
1132-43issue
6eissn
0006-3592issn
1097-0290journal_volume
100pub_type
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