Transmembrane Protein Activation Refined by Site-Specific Hydration Dynamics

Authors

  • Sunyia Hussain,

    1. Department of Chemical Engineering and Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA 93016 (USA)
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  • Dr. John M. Franck,

    1. Department of Chemical Engineering and Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA 93016 (USA)
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  • Prof. Songi Han

    Corresponding author
    1. Department of Chemical Engineering and Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA 93016 (USA)
    • Department of Chemical Engineering and Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA 93016 (USA)
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  • This work was supported by the Institute for Collaborative Biotechnologies through grant W911NF-09-0001 from the U.S. Army Research Office. The content of the information does not necessarily reflect the position or the policy of the Government, and no official endorsement should be inferred. We also acknowledge support by the Packard foundation for Science and Engineering, and the use of NMR facilities funded by the NSF MRSEC grant DMR-1121053. J.M.F. acknowledges support of the Elings Postdoctoral Fellowship, UCSB CNSI. We thank Dr. Alexander Mikhailovsky for the setup and design of time-resolved optical absorption spectroscopy, Devin Edwards and Evan Geller for the setup of the laser-triggered EPR spectroscopy, and Dr. Katherine Stone, Anna Pavlova, Jeda Voska, Christopher Carnabatu, Aye Aye, and Maia Kinnebrew for development of molecular biology and protein purification procedures. The PR gene with the E108Q mutation and His-tag was provided by Dr. Gregg Whited (Genencor). Our work on PR started as a collaboration with Prof. Galen Stucky, Christopher Knoll, Dr. Chi Nguyen, Dr. Hongjun Liang, and Dr. Gregg Whited. We also thank Dr. Brandon Armstrong for apomyoglobin ODNP data given in the Supporting Information.

Abstract

original image

Proteins on film: The Overhauser dynamic nuclear polarization method resolves hydration dynamics to an unprecedented level of detail for a transmembrane protein surface. The heterogeneous hydration landscape of proteorhodopsin rearranges upon photoactivation (see picture), thus providing an insight into how water contributes to protein function even for biological systems embedded in a hydrophobic membrane.

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