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Determination of High-affinity Antibody-antigen Binding Kinetics Using Four Biosensor Platforms
Published on: April 17, 2017
Antibody-Antigen Interaction Dynamics Revealed by Analysis of Single-Molecule Equilibrium Fluctuations on Individual
Srdjan S Aćimović1, Hana Šípová-Jungová1, Gustav Emilsson2
1Department of Physics , Chalmers University of Technology , 412 96 Göteborg , Sweden.
Abstract:
Antibody-antigen interactions are complex events central to immune response, in vivo and in vitro diagnostics, and development of therapeutic substances. We developed an ultrastable single-molecule localized surface plasmon resonance (LSPR) sensing platform optimized for studying antibody-antigen interaction kinetics over very long time scales. The setup allowed us to perform equilibrium fluctuations analysis of the PEG/anti-PEG interaction. By time and frequency domain analysis, we demonstrate that reversible adsorption of monovalently bound anti-PEG antibodies is the dominant factor affecting the LSPR fluctuations. The results suggest that equilibrium fluctuation analysis can be an alternative to established methods for determination of interaction rates. In particular, the methodology is suited to analyze molecular systems whose properties change during the initial interaction phases, for example, due to mass transport limitations or, as demonstrated here, because the effective association rate constant varies with surface concentration of adsorbed molecules.
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