A1 Journal article (refereed)
The Photocycle of Bacteriophytochrome Is Initiated by Counterclockwise Chromophore Isomerization (2022)

Morozov, D., Modi, V., Mironov, V., & Groenhof, G. (2022). The Photocycle of Bacteriophytochrome Is Initiated by Counterclockwise Chromophore Isomerization. Journal of Physical Chemistry Letters, 13, 4538-4542. https://doi.org/10.1021/acs.jpclett.2c00899

JYU authors or editors

Publication details

All authors or editors: Morozov, Dmitry; Modi, Vaibhav; Mironov, Vladimir; Groenhof, Gerrit

Journal or series: Journal of Physical Chemistry Letters

ISSN: 1948-7185

eISSN: 1948-7185

Publication year: 2022

Publication date: 16/05/2022

Volume: 13

Pages range: 4538-4542

Publisher: American Chemical Society (ACS)

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1021/acs.jpclett.2c00899

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/82151

Abstract

Photoactivation of bacteriophytochrome involves a cis–trans photoisomerization of a biliverdin chromophore, but neither the precise sequence of events nor the direction of the isomerization is known. Here, we used nonadiabatic molecular dynamics simulations on the photosensory protein dimer to resolve the isomerization mechanism in atomic detail. In our simulations the photoisomerization of the D ring occurs in the counterclockwise direction. On a subpicosecond time scale, the photoexcited chromophore adopts a short-lived intermediate with a highly twisted configuration stabilized by an extended hydrogen-bonding network. Within tens of picoseconds, these hydrogen bonds break, allowing the chromophore to adopt a more planar configuration, which we assign to the early Lumi-R state. The isomerization process is completed via helix inversion of the biliverdin chromophore to form the late Lumi-R state. The mechanistic insights into the photoisomerization process are essential to understand how bacteriophytochrome has evolved to mediate photoactivation and to engineer this protein for new applications.

Keywords: photochemistry; proteins; isomerism; computational chemistry

Free keywords: absorption; isomerization; photoisomerization; chromophores; computational chemistry

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Ministry reporting: Yes

Reporting Year: 2022

Preliminary JUFO rating: 3