A theoretical method to determine unstressed off-rate from multiple bond force spectroscopy

Area of Science:

• Biophysics
• Chemical Physics
• Materials Science

Background:

• Measuring kinetic off-rates of intermolecular bonds typically requires isolating single molecules.
• Existing methods lack tractable analytic approaches for analyzing rupture events in large numbers of bonds under dynamic forces.

Purpose of the Study:

• To introduce a novel analytical method for determining the unstressed off-rate from dynamic force spectroscopy (DFS) experiments involving multiple bond ruptures.
• To validate the proposed method against established models and simulations.

Main Methods:

• Development of a novel analytical method to calculate unstressed off-rates from DFS data of multiple bond ruptures.
• Utilizing both the Bell and Dembo models for theoretical analysis.
• Comparison with Monte Carlo simulations of DFS experiments with varying initial bond numbers and loading rates.

Main Results:

• The proposed method accurately determines the unstressed off-rate from multi-bond DFS experiments.
• Calculated unstressed off-rates show good agreement with prescribed values in simulations.
• The method is effective across a range of initial bond numbers (50-500) and loading rates (10^3-10^6 pN/s).

Conclusions:

• A new, tractable analytical method enables the measurement of intermolecular bond kinetic off-rates from multi-bond DFS experiments.
• This advancement removes the need for single-molecule isolation in such measurements.
• The method provides reliable kinetic off-rate data, applicable in various biophysical and materials science contexts.