Dual photoisomerization on distinct potential energy surfaces in a UV-absorbing rhodopsin

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F20%3A00536453" target="_blank" >RIV/68378271:_____/20:00536453 - isvavai.cz</a>

Result on the web

<a href="http://hdl.handle.net/11104/0314228" target="_blank" >http://hdl.handle.net/11104/0314228</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/jacs.0c03229" target="_blank" >10.1021/jacs.0c03229</a>

Result language

angličtina

Original language name

Dual photoisomerization on distinct potential energy surfaces in a UV-absorbing rhodopsin

Original language description

UV-absorbing rhodopsins are essential for UV vision and sensing in all kingdoms of life. Unlike the well-known visible-absorbing rhodopsins, which bind a protonated retinal Schiff base for light absorption, UV-absorbing rhodopsins bind an unprotonated retinal Schiff base. Thus far, the photoreaction dynamics and mechanisms of UV-absorbing rhodopsins have remained essentially unknown. Here, we report the complete excited- and ground-state dynamics of the UV form of histidine kinase rhodopsin 1 (HKR1) from eukaryotic algae, using femtosecond stimulated Raman spectroscopy (FSRS) and transient absorption spectroscopy, covering time scales from femtoseconds to milliseconds. We found that energy-level ordering is inverted with respect to visible-absorbing rhodopsins, with an optically forbidden low-lying S-1 excited state that has Ag- symmetry and a higher-lying UV-absorbing S-2 state of Bu+ symmetry. UV-photoexcitation to the S-2 state elicits a unique dual-isomerization reaction: first, C13=C14 cis-trans isomerization occurs during S-2-S-1 evolution in <100 fs. This very fast reaction features the remarkable property that the newly formed isomer appears in the excited state rather than in the ground state. Second, C15=N16 anti-syn isomerization occurs on the S-1-S-0 evolution to the ground state in 4.8 ps. We detected two ground-state unprotonated retinal photoproducts, 13-trans/15-anti (all-trans) and 13-cis/15-syn, after relaxation to the ground state. These isomers become protonated in 58 mu s and 3.2 ms, respectively, resulting in formation of the blue-absorbing form of HKR1. Our results constitute a benchmark of UV-induced photochemistry of animal and microbial rhodopsins.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10610 - Biophysics

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of the American Chemical Society

ISSN

0002-7863

e-ISSN

—

Volume of the periodical

142

Issue of the periodical within the volume

26

Country of publishing house

US - UNITED STATES

Number of pages

10

Pages from-to

11464-11473

UT code for WoS article

000547329800018

EID of the result in the Scopus database

2-s2.0-85087468750