A new twist in the photophysics of the GFP chromophore: a volume-conserving molecular torsion couple
dc.contributor.author
dc.date.accessioned
2019-05-06T11:16:55Z
dc.date.available
2019-05-06T11:16:55Z
dc.date.issued
2018-02-21
dc.identifier.issn
2041-6520
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dc.description.abstract
The simple structure of the chromophore of the green fluorescent protein (GFP), a phenol and an imidazolone ring linked by a methyne bridge, supports an exceptionally diverse range of excited state phenomena. Here we describe experimentally and theoretically the photochemistry of a novel sterically crowded nonplanar derivative of the GFP chromophore. It undergoes an excited state isomerization reaction accompanied by an exceptionally fast (sub 100 fs) excited state decay. The decay dynamics are essentially independent of solvent polarity and viscosity. Excited state structural dynamics are probed by high level quantum chemical calculations revealing that the fast decay is due to a conical intersection characterized by a twist of the rings and pyramidalization of the methyne bridge carbon. The intersection can be accessed without a barrier from the pre-twisted Franck-Condon structure, and the lack of viscosity dependence is due to the fact that the rings twist in the same direction, giving rise to a volume-conserving decay coordinate. Moreover, the rotation of the phenyl, methyl and imidazolone groups is coupled in the sterically crowded structure, with the methyl group translating the rotation of one ring to the next. As a consequence, the excited state dynamics can be viewed as a torsional couple, where the absorbed photon energy leads to conversion of the out-of-plane orientation from one ring to the other in a volume conserving fashion. A similar modification of the range of methyne dyes may provide a new family of devices for molecular machines, specifically torsional couples
dc.description.sponsorship
LB acknowledges financial support from Spanish Ministerio deEconomía y Competitividad (UNGI10-4E-801, CTQ2015-69363-P), Departament d'Innovació, Universitats i Empresa (DIUE) from Generalitat de Catalunya (2014SGR-1202), and computational time from Consorci de Serveis Universitaris de Catalunya. SRM is grateful to EPSRC for financial support (EP/M001997/01)
dc.format.extent
10 p.
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application/pdf
dc.language.iso
eng
dc.publisher
Royal Society of Chemistry (RSC)
dc.relation
info:eu-repo/grantAgreement/MINECO//CTQ2015-69363-P/ES/OMPUTACION DEL ESTADO EXCITADO: DE ESPECTROS MOLECULARES A SISTEMAS MULTICROMOFORICOS/
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Reproducció digital del document publicat a: https://doi.org/10.1039/c7sc04091a
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Chemical Science, 2018, vol. 9, núm. 7, p. 1803-1812
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Articles publicats (D-Q)
dc.rights
Reconeixement 4.0 Internacional
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dc.source
Conyard, Jamie Heisler, Ismael A. Chan, Yohan Page, Philip C. Bulman Meech, Stephen R. Blancafort San José, Lluís 2018 A new twist in the photophysics of the GFP chromophore: a volume-conserving molecular torsion couple Chemical Science 9 7 1803 1812
dc.subject
dc.title
A new twist in the photophysics of the GFP chromophore: a volume-conserving molecular torsion couple
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/openAccess
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.identifier.idgrec
029050
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dc.relation.ProjectAcronym
dc.identifier.eissn
2041-6539