title: Comparative energy measurements in single molecule interactions.
abstract: Single molecule experiments have opened promising new avenues of investigations in biology, but the quantitative interpretation of results remains challenging. In particular, there is a need for a comparison of such experiments with theoretical methods. We experimentally determine the activation free energy for single molecule interactions between two synaptic proteins syntaxin 1A and synaptobrevin 2, using an atomic force microscope and the Jarzynski equality of nonequilibrium thermodynamics. The value obtained is shown to be reasonably consistent with that from single molecule reaction rate theory. The temperature dependence of the spontaneous dissociation lifetime along with different pulling speeds is used to confirm the approach to the adiabatic limit. This comparison of the Jarzynski equality for intermolecular interactions extends the procedure for calculation of activation energies in nonequilibrium processes.
authors: Department of Physics and Astronomy, University of California at Riverside, Riverside, California, USA.
authors: W
authors: W
authors: Liu
authors: Vedrana
authors: V
authors: Montana
authors: Vladimir
authors: V
authors: Parpura
authors: U
authors: U
authors: Mohideen
mesh_terms: D003198:Computer Simulation; D004735:Energy Transfer; D008846:Micromanipulation / Q000379:methods*; D018625:Microscopy, Atomic Force / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D025941:Protein Interaction Mapping / Q000379:methods*; D050827:Syntaxin 1 / Q000737:chemistry* / Q000648:ultrastructure; D013816:Thermodynamics; D050988:Vesicle-Associated Membrane Protein 2 / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D050827:Syntaxin 1; D050988:Vesicle-Associated Membrane Protein 2