Primary Peptide Folding Dynamics Observed with Ultrafast Temperature Jump

Authors

  • Omar F. Mohammed,

    1. Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125 (USA), Fax: (+1) 626-792-8456
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  • Gouri S. Jas,

    1. Department of Chemistry, Biochemistry, and Institute of Biomedical Studies, Room: C322 Baylor University, 101 Bagby Avenue, Waco, TX 76706 (USA)
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  • Milo M. Lin,

    1. Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125 (USA), Fax: (+1) 626-792-8456
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  • Ahmed H. Zewail

    1. Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125 (USA), Fax: (+1) 626-792-8456
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  • We are grateful to the National Science Foundation and National Institutes of Health for funding of this research at Caltech. M.M.L. acknowledges financial support from the Krell Institute and the US Department of Energy (DoE) for a graduate fellowship at Caltech. We thank Dr. Dmitry Shorokhov for his effort in establishing the needed computation facility and for stimulating discussions. We also acknowledge the technical assistance of Drs. Hairong Ma and Chaozhi Wan in the laser T-jump setup. G.S.J. gratefully acknowledges Krzysztof Kuczera and William Eaton for helpful discussion.

Abstract

original image

Fastest folding: An ultrafast laser temperature jump (T-jump) induces folding and unfolding of Wh5 (see picture), the shortest possible α-helical peptide. Using time-resolved fluorescence spectroscopy, the folding time of this peptide was found to span from less than one nanosecond to a few nanoseconds, redefining the meaning of ultrafast dynamics in protein and peptide folding.

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