Abstract
Actin filaments play important roles in many kinds of cellular function by interacting with hundreds of actin binding proteins (ABP). Actin filament is dynamically changed under influence of mechanical and biochemical factors. In order to investigate actin filament dynamics, it is important to measure actin filament and ABP interactions quantitatively. In this study, we probe the interaction between actin filament and a-actinin using an AFM and dynamic force spectroscopy (DFS). By the DFS analysis, the dissociation constant of actin filaments and a-actinin binding was estimated, and the value was in good agreement with previously reported one which was obtained by an optical tweezer. We proposed that the present method would be useful for the interaction measurement of actin filaments and many kinds of binding proteins, and could be further applied to the actin dynamics measurement.
