A New Approach to Analysis of Single-Molecule Force Measurements
A common aim in probing single molecular bonds or the structural stability of proteins is to measure the kinetic rates at which a bond dissociates or a protein changes conformation under conditions of changing force. Using sample data taken from tests of ligand–receptor unbinding and protein unfolding/refolding, we show that populations of “single molecule” events, arranged into statistical arrays expressing the numbers of bonds or initial conformers remaining as a function of time and cumulated into histograms of transitions over fixed time increments, provide the bases for a model-independent assay of the kinetic rates of transition throughout the course of an experiment. Most important, this assay for kinetic rates can be employed with any deterministic mode of force spectroscopy, whether the pulling force increases or decreases with time.
KeywordsKinetic Rate Force Probe Initial State Probability Fast Ramp Force Ramp
This work was supported by National Institutes of Health grants HL65333 and HL31579.
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