Experimental measurement of binding energy, selectivity, and allostery using fluctuation theorems

Abstract

Pulling macromolecules apart Many biological processes involve macromolecular interactions, and knowing the binding energies of these interactions is key to a functional understanding. There are several experimental approaches to calculate binding energies in bulk solutions, but these require that the binding is at equilibrium. Bulk measurements may also mask different binding modes or concerted binding by several subunits. Camunas-Soler et al. used a fluctuation theorem for binding reactions to extract ligand binding energies directly from force experiments that probed a single binding reaction. They resolved binding energies of peptides to specific and non-specific DNA binding sites with affinities spanning six orders of magnitude. Science , this issue p. 412