Dynamic force spectroscopy on multiple bonds: Experiments and model

¹  University of Heidelberg, Bioquant 0013 - Im Neuenheimer Feld 267, D-69120 Heidelberg, Germany
²  FOM Institute for Atomic and Molecular Physics - Kruislaan 407, 1098 SJ Amsterdam, The Netherlands
³  Laboratoire de Physico-Chimie Curie, Institut Curie - F-75005 Paris, France

Received: 26 January 2007
Accepted: 12 December 2007

Abstract

We probe the dynamic strength of multiple biotin-streptavidin adhesion bonds under linear loading using the biomembrane force probe setup for dynamic force spectroscopy. Measured rupture force histograms are compared to results from a master equation model for the stochastic dynamics of bond rupture under load. This allows us to extract the distribution of the number of initially closed bonds. We also extract the molecular parameters of the adhesion bonds, in good agreement with earlier results from single-bond experiments. Our analysis shows that the peaks in the measured histograms are not simple multiples of the single-bond values, but follow from a superposition procedure which generates different peak positions.