Recovery of Free Energy Branches in Single Molecule Experiments

Ivan Junier, Alessandro Mossa, Maria Manosas, Felix Ritort
2009 Physical Review Letters  
We present a method for determining the free energy of coexisting states from irreversible work measurements. Our approach is based on a fluctuation relation that is valid for dissipative transformations in partially equilibrated systems. To illustrate the validity and usefulness of the approach, we use optical tweezers to determine the free energy branches of the native and unfolded states of a two-state molecule as a function of the pulling control parameter. We determine, within 0.6 kT
more » ... cy, the transition point where the free energies of the native and the unfolded states are equal.
doi:10.1103/physrevlett.102.070602 pmid:19257655 fatcat:r3es2g4t2vhjhcyownztukwhuy