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Distance versus energy fluctuations and electron transfer in single protein molecules

Tang, Jau and Lin, Sheng-Hsein (2006) Distance versus energy fluctuations and electron transfer in single protein molecules. Physical Review E, 73 (6). Art. No. 061108. ISSN 1539-3755. doi:10.1103/PhysRevE.73.061108.

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Stochastic nature due to distance and energy fluctuations of single protein molecules involved in electron-transfer (ET) reactions is studied. Distance fluctuations have been assumed previously for causing the slow fluctuations in the ET rates between a donor-acceptor pair constrained to a native protein. Although the observed t–1/2 power law can be derived using Langevin dynamics with a simple chain model, some discrepancies exist. The friction coefficient and the Rouse segment time constant deduced from experimental data are several orders of magnitude too large, even though the extracted force constant is reasonable. Therefore, questions are raised about the distance-fluctuation mechanism and the activationless ET hypothesis. As an alternative mechanism, we considered fluctuations in activation energy and analyzed the data from two different single protein experiments to determine spectral distribution of energy fluctuations.

Item Type:Article
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Tang, Jau0000-0003-2078-1513
Additional Information:© 2006 The American Physical Society (Received 15 March 2006; published 27 June 2006) J.T. acknowledges the support by the James W. Glanville Foundation at the California Institute of California while a major part of the work was completed. The authors thank R.A. Marcus for stimulating discussion. J.T. also thanks X.S. Xie, A.H. Zewail, H. Yang, M.K. Prakash, and M.E. Michel-Beyerle for discussions about the issues concerning the ps and ns fluorescence-decay components in flavoproteins. The help by B. Leigh and B. Tang in preparation of Figs. 1 and 2 is acknowledged.
Funding AgencyGrant Number
James W. Glanville FoundationUNSPECIFIED
Subject Keywords:proteins; molecular biophysics; charge exchange; fluctuations; stochastic processes; friction
Issue or Number:6
Record Number:CaltechAUTHORS:TANpre06b
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5208
Deposited By: Archive Administrator
Deposited On:05 Oct 2006
Last Modified:08 Nov 2021 20:23

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