Zhang Lin, Narayanan Niju, Brand Stephen R, Nicolette Charles A, Baroja Miren, Arp Jacqueline, Wang Hao, Moo-Young Murray, Chou C Perry
Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Protein Expr Purif. 2010 Oct;73(2):140-6. doi: 10.1016/j.pep.2010.05.016. Epub 2010 Jun 8.
The formation of aberrant disulfide bonds is a structural consideration for the manufacturing of the extracellular domain of human CD83 (hCD83ext), a potential therapeutic protein. In certain instances, hCD83ext protein products, even when stored frozen, tended to dimerize or even multimerize through the formation of aberrant intermolecular disulfide bonds. Herein, we discovered an analytical inconsistency and applied a modified sample preparation protocol for proper structural analysis of hCD83ext products which are heterologously expressed in Escherichia coli and subsequently purified. In addition, a mutant derivative with the Cys100Ser mutation was identified as an improved version which did not form dimers or multimers. The identification of this mutant variant as a more potent therapeutic protein than other hCD83ext species demonstrated that the structural variation associated with disulfide bond formation can be a critical issue for rigorous control of the quality and bioactivity of therapeutic proteins. The application of this mutant variant for protein therapeutics is currently under exploration.
