Intact and subunit-specific analysis of bispecific antibodies by sheathless CE-MS.

Intact and subunit-specific analysis of bispecific antibodies by sheathless CE-MS.
Anal Chim Acta. 2020 Oct 16;1134:18-27
Authors: Gstöttner C, Nicolardi S, Haberger M, Reusch D, Wuhrer M, Domínguez-Vega E
Abstract
Bispecific antibodies (BsAb) are next-generation, antibody-based pharmaceuticals which come with a great functional versatility and often a vast structural heterogeneity. Although engineering of the primary sequence of BsAbs guides the proper pairing of the different chains, several side products can often be observed contributing to the macroheterogeneity of these products. Furthermore, changes in the amino acid sequence can result in different protein modifications which can affect the properties of the antibody and further increase the structural complexity. A multi-methods approach can be used for the characterization of their heterogeneity but new analytical strategies are needed for a more accurate and in-depth analysis. Here, we present a combination of intact antibody and subunit-specific mass measurements using sheathless capillary electrophoresis-mass spectrometry for assessing the macro- and microheterogeneity of BsAbs. Two homologous BsAbs with the same bispecificity but slightly different amino acid sequences were analyzed. Intact measurements were performed using a positively coated capillary and a background electrolyte (BGE) consisting of 3% acetic acid. For intact BsAbs, the separation permitted the char...

Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Gstöttner C, Nicolardi S, Haberger M, Reusch D, Wuhrer M, Domínguez-Vega E Tags: Anal Chim Acta Source Type: research