Refined procedure of evaluating experimental single-molecule force spectroscopy data

Alexander Fuhrmann, Dario Anselmetti, Robert Ros, Sebastian Getfert, Peter Reimann
2008 Physical Review E  
Dynamic force spectroscopy is a well-established tool to study molecular recognition in a wide range of binding affinities on the single-molecule level. The theoretical interpretation of these data is still very challenging and the models describe the experimental data only partly. In this paper we reconsider the basic assumptions of the models on the basis of an experimental data set and propose an approach of analyzing and quantitatively evaluating dynamic force spectroscopy data on single
more » ... y data on single ligand-receptor complexes. We present our procedure to process and analyze the force-distance curves, to detect the rupture events in an automated manner, and to calculate quantitative parameters for a biophysical characterization of the investigated interaction. FIG. 1. Schematic illustration of a dynamic force spectroscopy experiment. The receptor ͑e.g., a protein͒ is immobilized on the surface ͑e.g., mica͒ and the ligand ͑e.g., a DNA-fragment͒ is connected via a linker ͓e.g., poly͑ethylene glycol͒ ͑PEG͔͒ to the tip of an AFM cantilever which serves as a force transducer. The distance between the mica surface and tip can be controlled with a piezoelectric element. When the surface is pulled down at a constant speed v, monotonically increasing forces act on the ligand-receptor complex.
doi:10.1103/physreve.77.031912 pmid:18517427 fatcat:5x2bkuhi3rh4demtodoo4om2ii