From Capture Strategy to Candidate Selection: Optimizing SPR Assays for FcRn and FcγR Characterization in Antibody Discovery

Abstract:

Surface plasmon resonance (SPR) plays a pivotal role in antibody discovery and engineering by enabling quantitative characterization of Fc–receptor interactions. However, robust affinity determination relies on selecting the appropriate capture strategy, as ligand orientation, receptor presentation and assay format can all influence kinetic measurements and data interpretation. We present a suite of SPR assay formats tailored for the characterization of Fc interactions including FcRn and Fcγ receptors. By applying receptor-specific capture strategies, we demonstrate how experimental design directly impacts affinity determination and assay performance. Combined with orthogonal approaches, these analytical workflows provide high-confidence data to support Fc engineering, improve candidate selection, and accelerate the development of next-generation antibody therapeutics.