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dc.contributor.authorMix, L. Tyler
dc.contributor.authorCarroll, Elizabeth C.
dc.contributor.authorMorozov, Dmitry
dc.contributor.authorPan, Jie
dc.contributor.authorGordon, Wendy Ryan
dc.contributor.authorPhilip, Andrew
dc.contributor.authorFuzell, Jack
dc.contributor.authorKumauchi, Masato
dc.contributor.authorvan Stokkum, Ivo
dc.contributor.authorGroenhof, Gerrit
dc.contributor.authorHoff, Wouter D.
dc.contributor.authorLarsen, Delmar S.
dc.date.accessioned2018-04-17T11:43:06Z
dc.date.available2019-02-21T22:35:25Z
dc.date.issued2018
dc.identifier.citationMix, L. T., Carroll, E. C., Morozov, D., Pan, J., Gordon, W. R., Philip, A., . . . Larsen, D. S. (2018). Excitation-Wavelength Dependent Photocycle Initiation Dynamics Resolve Heterogeneity in the Photoactive Yellow Protein from Halorhodospira halophila. <em>Biochemistry</em>, 57 (1), 1733-1747. <a href="https://doi.org/10.1021/acs.biochem.7b01114">doi:10.1021/acs.biochem.7b01114</a>
dc.identifier.otherTUTKAID_76861
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/57658
dc.description.abstractPhotoactive yellow proteins (PYPs) make up a diverse class of blue-light-absorbing bacterial photoreceptors. Electronic excitation of the p-coumaric acid chromophore covalently bound within PYP results in triphasic quenching kinetics; however, the molecular basis of this behavior remains unresolved. Here we explore this question by examining the excitation-wavelength dependence of the photodynamics of the PYP from Halorhodospira halophila via a combined experimental and computational approach. The fluorescence quantum yield, steady-state fluorescence emission maximum, and cryotrapping spectra are demonstrated to depend on excitation wavelength. We also compare the femtosecond photodynamics in PYP at two excitation wavelengths (435 and 475 nm) with a dual-excitation-wavelength-interleaved pump–probe technique. Multicompartment global analysis of these data demonstrates that the excited-state photochemistry of PYP depends subtly, but convincingly, on excitation wavelength with similar kinetics with distinctly different spectral features, including a shifted ground-state beach and altered stimulated emission oscillator strengths and peak positions. Three models involving multiple excited states, vibrationally enhanced barrier crossing, and inhomogeneity are proposed to interpret the observed excitation-wavelength dependence of the data. Conformational heterogeneity was identified as the most probable model, which was supported with molecular mechanics simulations that identified two levels of inhomogeneity involving the orientation of the R52 residue and different hydrogen bonding networks with the p-coumaric acid chromophore. Quantum calculations were used to confirm that these inhomogeneities track to altered spectral properties consistent with the experimental results.
dc.language.isoeng
dc.publisherAmerican Chemical Society
dc.relation.ispartofseriesBiochemistry
dc.subject.otherPhotoactive Yellow Proteins
dc.titleExcitation-Wavelength Dependent Photocycle Initiation Dynamics Resolve Heterogeneity in the Photoactive Yellow Protein from Halorhodospira halophila
dc.typearticle
dc.identifier.urnURN:NBN:fi:jyu-201804061946
dc.contributor.laitosKemian laitosfi
dc.contributor.laitosDepartment of Chemistryen
dc.contributor.oppiaineFysikaalinen kemia
dc.type.urihttp://purl.org/eprint/type/JournalArticle
dc.date.updated2018-04-06T12:15:12Z
dc.description.reviewstatuspeerReviewed
dc.format.pagerange1733-1747
dc.relation.issn1520-4995
dc.relation.volume57
dc.type.versionacceptedVersion
dc.rights.copyright© 2018 American Chemical Society. This is a final draft version of an article whose final and definitive form has been published by American Chemical Society. Published in this repository with the kind permission of the publisher
dc.rights.accesslevelopenAccessfi
dc.relation.doi10.1021/acs.biochem.7b01114


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