Development and properties of recombinant proteins based on the broadly neutralizing antibody to influenza A virus

Abstract

We studied the possibility of using a broadly neutralizing anti-influenza A antibody as a module for the development of different protein constructs for diagnostics. For this purpose, we constructed two recombinant proteins—a Fab-fragment of the antibody and Fab-mCherry, which is a hybrid of the Fab-fragment and the mCherry fluorescent protein. Both proteins were expressed in Escherichia coli cells and purified in a functionally active state from culture medium. The antibody Fab-fragment was shown to bind all 11 tested strains of the influenza A H1N1 and H3N2 subtypes. A stronger binding was observed for group I hemagglutinins; this correlates with the immunochemical profile of the parental antibody. Comparison of the dissociation constants of complexes of the antibody Fab-fragment and Fab-mCherry with A(H1N1)/Solomon Islands/03/06 virus particles demonstrated that the attachment of the mCherry protein did not interfere with the antigen-binding properties of the antibody Fab-fragment.