2010 Volume 31 Issue 1 Pages 41-47
Probing the step-by-step bonding processes induced by the individual interactions in a molecular complex and their variation with the surrounding conditions is a key factor for enabling further advances in biophysics and chemistry and their applications. Here, we demonstrate a methodology that realizes the site-selective anatomy of molecular interactions at the single-molecule level. With the combination of cross-linkers and the atomic force microscopy (AFM) that we developed to enable a precise analysis by dynamic force spectroscopy (DFS), direct and bridged interactions at each reaction site in a typical ligand-receptor system, streptavidin-biotin complex, were clearly distinguished and individually analyzed for the first time, providing a greater understanding of step-by-step progress of the bonding process. This methodology will provide a foundation for further advances in biophysics and chemistry and their applications, such as designing and controlling the mechanism of chemical reactions between functional molecules.
