Accuracy Estimation in Force Spectroscopy Experiments

Abstract

Force spectroscopy is a useful tool for the investigation of molecular interactions. We here present a detailed analysis of parameter estimation in force spectroscopy experiments. It provides the values of the statistical errors of the kinetic off-rate constant koff and the energy length scale xβ to be considered using the single barrier model. As a biologically relevant experimental system we used the interaction between human rhinovirus serotype 2 and a recombinant derivative of the very-low density lipoprotein receptor. The interaction forces of single virus–receptor pairs were measured at different loading rates and analysed according to the single barrier model. Accuracy estimates of koff and xβ were obtained by Monte Carlo simulation and bootstrapping. For this model of virus–receptor attachment, force spectroscopy experiments yielded xβ=(0.38±0.07) nm and ln koff=(-2.3±1.0)ln s-1.