Premium
Impact of the isoelectric point of model parvoviruses on viral retention in anion‐exchange chromatography
Author(s) -
Leisi Remo,
Wolfisberg Raphael,
Nowak Thomas,
Caliaro Oliver,
Hemmerle Andreas,
Roth Nathan J.,
Ros Carlos
Publication year - 2021
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.27555
Subject(s) - isoelectric point , capsid , minute virus of mice , chromatofocusing , chemistry , isoelectric focusing , parvovirus , ion chromatography , chromatography , hydrophilic interaction chromatography , virus , biophysics , biochemistry , parvoviridae , biology , virology , enzyme , high performance liquid chromatography , gene
Anion‐exchange chromatography (AEX) is used in the downstream purification of monoclonal antibodies to remove impurities and potential viral contamination based on electrostatic interactions. Although the isoelectric point (pI) of viruses is considered a key factor predicting the virus adsorption to the resin, the precise molecular mechanisms involved remain unclear. To address this question, we compared structurally homologous parvoviruses that only differ in their surface charge distribution. A single charged amino acid substitution on the capsid surface of minute virus of mice (MVM) provoked an increased apparent pI (pI app ) 6.2 compared to wild‐type MVM (pI app = 4.5), as determined by chromatofocusing. Despite their radically different pI app , both viruses displayed the same interaction profile in Mono Q AEX at different pH conditions. In contrast, the closely related canine parvovirus (pI app = 5.3) displayed a significantly different interaction at pH 5. The detailed structural analysis of the intricate three‐dimensional structure of the capsids suggests that the charge distribution is critical, and more relevant than the pI, in controlling the interaction of a virus with the chromatographic resin. This study contributes to a better understanding of the molecular mechanisms governing virus clearance by AEX, which is crucial to enable robust process design and maximize safety.