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Protein conformational dynamics probed by single-molecule electron transfer.

Haw Yang·Guobin Luo·Pallop Karnchanaphanurach·Tai-Man Louie·Ivan Rech·Sergio Cova·Luying Xun·X Sunney Xie
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Abstract

Electron transfer is used as a probe for angstrom-scale structural changes in single protein molecules. In a flavin reductase, the fluorescence of flavin is quenched by a nearby tyrosine residue by means of photo-induced electron transfer. By probing the fluorescence lifetime of the single flavin on a photon-by-photon basis, we were able to observe the variation of flavin-tyrosine distance over time. We could then determine the potential of mean force between the flavin and the tyrosine, and a correlation analysis revealed conformational fluctuation at multiple time scales spanning from hundreds of microseconds to seconds. This phenomenon suggests the existence of multiple interconverting conformers related to the fluctuating catalytic reactivity.

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Amino Acid SubstitutionCatalysisChemical PhenomenaChemistry, PhysicalComputer SimulationElectronsEscherichia coliFMN ReductaseFlavin MononucleotideFlavin-Adenine DinucleotideFlavinsFluorescenceHydrogen BondingLikelihood FunctionsMathematicsModels, MolecularMutagenesis, Site-DirectedPhotonsProtein ConformationSerineSpectrometry, FluorescenceTemperatureThermodynamicsTyrosineJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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Haw Yang, Guobin Luo, Pallop Karnchanaphanurach, Tai-Man Louie, Ivan Rech, Sergio Cova, Luying Xun, X Sunney Xie. 2003-10-10. Protein conformational dynamics probed by single-molecule electron transfer.. https://doi.org/10.1126/science.1086911

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