In single-molecule experiments forces can be exerted directly on individual molecules and their response can be followed as a function of time. These experiments reveal fundamentally novel and unique information on the structure, dynamics, and interactions of individual biomolecules. In collaboration with Dr. Szabo (NIDDK, NIH), we have continued our development of formalisms to extract accurate kinetic and thermodynamic information from single-molecule force spectroscopy experiments. We could show how system free energies can be transformed into the underlying molecular free energy surface, which is the quantity of interest (1). As part of this work, we also developed a theoretical description of the kinetics of rupture under force in a framework similar to a reaction-diffusion model. 1. G. Hummer, A. Szabo, Free energy profiles from single-molecule pulling experiments, Proc. Natl. Acad. Sci. USA 107, 21441-21446 (2010).

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Mittal, Jeetain; Hummer, Gerhard (2012) Pair diffusion, hydrodynamic interactions, and available volume in dense fluids. J Chem Phys 137:034110
Best, Robert B; Hummer, Gerhard (2011) Diffusion models of protein folding. Phys Chem Chem Phys 13:16902-11
Hummer, Gerhard (2010) Catching a protein in the act. Proc Natl Acad Sci U S A 107:2381-2
Hummer, Gerhard; Szabo, Attila (2010) Free energy profiles from single-molecule pulling experiments. Proc Natl Acad Sci U S A 107:21441-6
Frewen, Thomas A; Hummer, Gerhard; Kevrekidis, Ioannis G (2009) Exploration of effective potential landscapes using coarse reverse integration. J Chem Phys 131:134104
Berezhkovskii, Alexander; Hummer, Gerhard; Szabo, Attila (2009) Reactive flux and folding pathways in network models of coarse-grained protein dynamics. J Chem Phys 130:205102
Best, Robert B; Hummer, Gerhard (2009) Biochemistry. Unfolding the secrets of calmodulin. Science 323:593-4
Dudko, Olga K; Hummer, Gerhard; Szabo, Attila (2008) Theory, analysis, and interpretation of single-molecule force spectroscopy experiments. Proc Natl Acad Sci U S A 105:15755-60