Dynamic Force Spectroscopy on Single Biomolecules

Participating group members:	Mykhaylo Evstigneev, Sebastian Getfert, Peter Reimann
Main cooperation partners:	Dario Anselmetti (Biophysics and applied Nanoscience group at the University of Bielefeld; Robert Ros, Alexander Fuhrmann (Arizona State University)

Dynamic force spectroscopy is a widely used tool for investigating binding properties of biomolecular complexes (e.g. a receptor-ligand compound) at the atomic scale by means of the dissociation of single chemical bonds under an external force. Essentially, the molecular complex of interest is connected via suitable linkers (spacer molecules) to an atomic force microscope (or some other micromechanical device) and pulled apart at a constant speed v while monitoring the acting forces until the chemical bond ruptures (see figure). Since the molecular dissociation process is of stochastic nature, the theoretical interpretation of the observed rupture forces is a nontrivial task: upon repeating the same experiment at the same pulling velocity v several times, the rupture forces are found to be distributed over a wide range. Furthermore, for different pulling velocities v different such distributions are obtained. Hence, neither a single rupture event nor the average rupture force at any fixed pulling velocity can serve as a meaningful characteristic quantity of a given chemical bond strength. On the other hand, direct molecular dynamics simulations of the forced dissociation process are still very far from reaching experimentally realistic conditions due to the limited accessible timescale. Hence, nontrivial theoretical modeling steps are indispensable to analyse and interprete the experimental observations. This is the purpose of our present project.

Publications:

M. Evstigneev and P. Reimann
Dynamic force spectroscopy: Optimized data analysis
Phys. Rev. E 68, 045103(R) (2003)

M. Raible, M. Evstigneev, P. Reimann, F. W. Bartels, and R. Ros
Theoretical analysis of dynamic force spectroscopy experiments on ligand-receptor complexes
J. Biotech. 112, 13 (2004)

M. Raible and P. Reimann
Single-molecule force spectroscopy: Heterogeneity of chemical bonds
Europhys. Lett. 73, 628 (2006)

M. Raible, M. Evstigneev, F. W. Bartels, R. Eckel, M. Nguyen-Duong, R. Merkel, R. Ros, D. Anselmetti, and P. Reimann
Theoretical Analysis of Single-Molecule Force Spectroscopy Experiments: Heterogeneity of Chemical Bonds
Biophys. J. 90, 3851 (2006)

S. Getfert and P. Reimann
Optimal evaluation of single-molecule force spectroscopy experiments
Phys. Rev. E 76, 052901 (2007)

A. Fuhrmann, D. Anselmetti, R. Ros, S. Getfert, and P. Reimann
Refined procedure of evaluating experimental single-molecule force spectroscopy data
Phys. Rev. E 77, 031912 (2008)

S. Getfert, M. Evstigneev, and P. Reimann
Single-molecule force spectroscopy: Practical limitations beyond Bell's model
Physica A 388, 1120 (2009)

S. Getfert and P. Reimann
Hidden Multiple Bond Effects in Dynamic Force Spectroscopy
Biophys. J. 102, 1184 (2012)

Related projects:

Friction phenomena on the nanometer scale

Decay of complex metastable states

Last modified on 2012-03-14