Dynamic force spectroscopy on multiple bonds: experiments and model

TL;DR

This study investigates the rupture forces of multiple biotin-streptavidin bonds under dynamic loading, combining experiments with a stochastic model to understand bond behavior and extract molecular parameters.

Contribution

It introduces a master equation model for multiple bond rupture dynamics and demonstrates how to interpret complex rupture force histograms.

Findings

Rupture force histograms reveal complex peak structures not simple multiples of single bonds.

The model accurately fits experimental data and extracts molecular parameters.

The analysis provides insights into the stochastic nature of multiple bond rupture.

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.