Temperature Dependence of the Biotin−Avidin Bond-Rupture Force Studied by Atomic Force Microscopy

Abstract

We report for the first time an atomic force microscopy (AFM) investigation of the dependence of unbinding force on temperature at controlled loading rate. AFM force measurements of biotin-avidin interactions were acquired at various temperatures ranging from 13 to 37°C using force loading rates that are slow enough to ignore dissipative friction and to assume thermal equilibrium. With our established Poisson statistical analysis method, the unbinding force at a fixed loading rate between an individual biotin-avidin pair was extracted and was found to decrease by ∼5-fold with increasing temperature over this range. On the basis of a thermodynamic model similar to that of Bell, but developed here with additional insights, the bond stiffness, effective unbinding length, and the critical unbinding energy per biotin-avidin complex were estimated. This work takes quantitative AFM studies to the next level by allowing energies to be determined from force measurements.

Force measurements with the atomic force microscope: Technique, interpretation and applications

“…Lo et al [1139] have studied also the temperature dependence of the biotin-avidin specific force rupture. AFM force measurements have been performed at various temperatures (13-37 8C) with slow constant loading rates.…”

Imaging Proteins with Atomic Force Microscopy: An Overview

“…This allows for the detection of the unbinding force (the maximum force at the moment of receptor-ligand detachment), which is obtained upon retraction of the cantilever from the surface. Recently, unbinding forces were quantified for various receptor-ligand pairs, including biotin-avidin [113], DNA bases [114], antibody-antigen [115][116][117], and cell-tocell recognition proteins [118][119][120]. It was also shown that the value of the unbinding force for a certain receptor-ligand pair is not unique but rather is dependent on the dynamics of the experiment [113,[121][122][123].…”

Assembly and actuation of nanomaterials using active biomolecules.

“…Linkage of nanoparticles to MTs shuttles was accomplished using biotin-streptavidin, forming a relatively strong, but non-covalent bond between components. 39 Nanoparticles were assembled on MTs that were bound to surface-tethered kinesin in order to avoid inhibition of transport as previously reported, 29 by localizing the attached cargo to the top and sides of the MT shuttles. The density of nanoparticles attached to MTs was the most significant factor affecting kinesin transport, and can be regulated by controlling the frequency of biotinylated tubulin, and/or the concentration of nanoparticles used for attachment.…”