Department of Physics , Chalmers University of Technology , 412 96 Göteborg , Sweden.
Department of Chemistry and Chemical Engineering , Chalmers University of Technology , 412 96 Göteborg , Sweden.
ACS Nano. 2018 Oct 23;12(10):9958-9965. doi: 10.1021/acsnano.8b04016. Epub 2018 Sep 5.
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.
抗体-抗原相互作用是免疫反应、体内和体外诊断以及治疗物质开发的核心复杂事件。我们开发了一种超稳定的单分子局域表面等离子体共振（LSPR）传感平台，该平台经过优化，可用于在非常长的时间范围内研究抗体-抗原相互作用动力学。该设置允许我们对 PEG/抗-PEG 相互作用进行平衡波动分析。通过时域和频域分析，我们证明了单价结合的抗-PEG 抗体的可逆吸附是影响 LSPR 波动的主要因素。结果表明，平衡波动分析可以替代确定相互作用速率的现有方法。特别是，该方法适用于分析在初始相互作用阶段其性质发生变化的分子系统，例如，由于质量传输限制，或者，如这里所示，由于有效缔合速率常数随吸附分子的表面浓度而变化。
