Journal of Chemical Physics, Vol.114, No.7, 3208-3214, 2001
Simulating the dynamic strength of molecular interactions
It has been demonstrated that the force at which an interaction will break depends on the rate at which force is applied. Here, we present a strategy for the modeling of the forced dissociation of a ligand-receptor interaction, using the streptavidin-biotin complex as an example, over a range of loading rates that are outside those attainable by current all-atom simulation techniques. The method adopted is a combination of traditional reaction coordinate mapping and Brownian dynamics. Our simulations predict a dynamic force spectrum for the streptavidin-biotin interaction of similar form to recent experimental results. In this study we confirm the logarithmic dependence of a rupture force on the loading rate, highlight the barriers that are probed at the loading rates attainable by the atomic force microscope, and discuss how these barriers transform under loading. Furthermore, it is confirmed that additional information obtained from the distribution of rupture forces can be used to complement dynamic force spectroscopy data and should be used in experimental studies to verify the results obtained.