Velocity convergence of free energy surfaces from single-molecule measurements using Jarzynski's equality.
We studied the velocity dependence of mechanical unfolding of single protein molecules with the atomic force microscope. We showed that with enough realizations, the free energy surfaces reconstructed from Jarzynski's equality converge with respect to pulling velocity, in good agreement with theory. Using the I27 domain of titin as an example, we estimated the required number of realizations for a given pulling velocity, and suggested the optimal range of velocities for single-molecule experiments. The results demonstrate that Jarzynski's equality is a powerful and practical tool for reconstructing free energy landscapes.
Harris
Nolan C
NC
Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA.
Kiang
Ching-Hwa
CH
D064211:Connectin; D006801:Humans; D018625:Microscopy, Atomic Force; D009124:Muscle Proteins / Q000737:chemistry*; D009206:Myocardium / Q000737:chemistry; D011336:Probability; D011487:Protein Conformation; D017510:Protein Folding; D011494:Protein Kinases / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*; D013816:Thermodynamics; D013997:Time Factors
D064211:Connectin; D009124:Muscle Proteins; D011506:Proteins; C577285:TTN protein, human; D011494:Protein Kinases