Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
Nat Commun. 2014 Apr 24;5:3724. doi: 10.1038/ncomms4724.
Interactions between a protein and a ligand are essential to all biological processes. Binding and dissociation are the two fundamental steps of ligand-protein interactions, and determine the binding affinity. Intrinsic conformational dynamics of proteins have been suggested to play crucial roles in ligand binding and dissociation. Here, we demonstrate how protein dynamics dictate the binding and dissociation of a ligand through a single-molecule kinetic analysis for a series of maltose-binding protein mutants that have different intrinsic conformational dynamics and dissociation constants for maltose. Our results provide direct evidence that the ligand dissociation is determined by the intrinsic opening rate of the protein.
蛋白质与配体的相互作用是所有生物过程的基础。结合和解离是配体-蛋白质相互作用的两个基本步骤，决定了结合亲和力。蛋白质的固有构象动力学被认为在配体结合和解离中起着至关重要的作用。在这里，我们通过对一系列麦芽糖结合蛋白突变体的单分子动力学分析，证明了蛋白质动力学如何通过改变麦芽糖结合蛋白的固有构象动力学和麦芽糖的解离常数来决定配体的结合和解离。我们的结果提供了直接证据，表明配体的解离取决于蛋白质的固有开口速率。
