English

Recovery of free energy branches in single molecule experiments

Soft Condensed Matter 2009-02-21 v1 Statistical Mechanics Biological Physics

Abstract

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 accuracy, the transition point where the free energies of the native and the unfolded states are equal.

Keywords

Cite

@article{arxiv.0901.3886,
  title  = {Recovery of free energy branches in single molecule experiments},
  author = {Ivan Junier and Alessandro Mossa and Maria Manosas and Felix Ritort},
  journal= {arXiv preprint arXiv:0901.3886},
  year   = {2009}
}

Comments

To appear in Phys. Rev. Lett. 4 pages + Supp. Mat. (6 pages)