Investigation into the Mechanical Properties of Tethered Disulfide Bonds by Single-Molecule Force Spectroscopy Using AFM

In the context of the project TETHERED, the present study aims to provide a detailed picture of the mechanical properties of disulfide bonds, which are dynamic covalent bonds, at the molecular level. Using an atomic force microscope, single polymer chains containing the bond of interest are examined using single-molecule force spectroscopy (SMFS) to understand how they respond to force. This technique allows us to measure the force at which the disulfide bond breaks. Thanks to the tethered system, the force curves characteristic of the bond follow a specific pattern that helps us to identify them unambiguously in the measurements. Additionally, the main advantage of the tethered bond is that after the rupture, the components of the bond are maintained in close proximity and therefore could reform the bond more easily. This characteristic allows us to study the detailed dynamical properties of the bond under mechanical strain. By varying conditions for the measurements (loading rate, duration and amplitude of the force, pH, solvent, competing agents,…), we should be able to discover new and interesting properties of the bond mechanics.