Engineering recombinant antibodies for polymer biofunctionalization

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.