Engineering recombinant antibodies for polymer biofunctionalization

Abstract

The attachment of recognition elements such as antibody fragments to polymeric substrates can be used to mediate cell- or protein-specific interactions. In this work, single-chain Fv (scFv) antibody fragments were isolated against two cell types of interest and expressed in an Escherichia coli expression platform. The scFvs were engineered at their C-terminus to incorporate a cysteine-containing linker, for reaction with maleimide-linked polymers, or a heptasaccharide glycan for complexation with surface amine moieties. Antigen binding of the modified scFvs was unchanged, and expression yields of the glyco-engineered scFvs were similar to the unmodified molecules, while cys-tagged scFv yields varied between scFv variants. Targeted immobilization of the scFvs via either modification resulted in three-to five-fold higher binding of ligands over adsorbed molecules. The study demonstrates a simple and efficient antibody engineering and modification approach for effective targeted immobilization on polymeric substrates. Copyright (C) 2015 John Wiley & Sons, Ltd.This work was supported by Irish Research Council (IRC) grantPD/2010/1689 (MJH), Science Foundation Ireland Grant 07/SRC/B1163 (CC, AS), Enterprise Ireland Science and TechnologyAgency Grant PC/2007/021 (SR) and European Union “EPICstent”Project Grant FP7-PEOPLE-2012-IAPP-324514 (SA)