Reversible Photochromic Reactions of Bacteriorhodopsin from Halobacterium salinarum at Femto- and Picosecond Times.

Autor: Smitienko O; Emanuel Institute of Biochemical Physics of the Russian Academy of Sciences, Kosygin St., 4, Moscow 119334, Russia., Feldman T; Emanuel Institute of Biochemical Physics of the Russian Academy of Sciences, Kosygin St., 4, Moscow 119334, Russia.; Department of Biology, Lomonosov Moscow State University, Leninskie Gory, 1, Moscow 119991, Russia., Shelaev I; Moscow Center for Advanced Studies, Kulakova Str. 20, Moscow 123592, Russia.; N.N. Semenov Federal Research Center for Chemical Physics of the Russian Academy of Sciences, Kosygin St., 4, Moscow 119991, Russia., Gostev F; Moscow Center for Advanced Studies, Kulakova Str. 20, Moscow 123592, Russia.; N.N. Semenov Federal Research Center for Chemical Physics of the Russian Academy of Sciences, Kosygin St., 4, Moscow 119991, Russia., Aybush A; Moscow Center for Advanced Studies, Kulakova Str. 20, Moscow 123592, Russia.; N.N. Semenov Federal Research Center for Chemical Physics of the Russian Academy of Sciences, Kosygin St., 4, Moscow 119991, Russia.; Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1, Moscow 119991, Russia., Cherepanov D; Department of Biology, Lomonosov Moscow State University, Leninskie Gory, 1, Moscow 119991, Russia.; Moscow Center for Advanced Studies, Kulakova Str. 20, Moscow 123592, Russia.; N.N. Semenov Federal Research Center for Chemical Physics of the Russian Academy of Sciences, Kosygin St., 4, Moscow 119991, Russia., Nadtochenko V; Moscow Center for Advanced Studies, Kulakova Str. 20, Moscow 123592, Russia.; N.N. Semenov Federal Research Center for Chemical Physics of the Russian Academy of Sciences, Kosygin St., 4, Moscow 119991, Russia.; Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1, Moscow 119991, Russia., Ostrovsky M; Emanuel Institute of Biochemical Physics of the Russian Academy of Sciences, Kosygin St., 4, Moscow 119334, Russia.; Department of Biology, Lomonosov Moscow State University, Leninskie Gory, 1, Moscow 119991, Russia.
Jazyk: angličtina
Zdroj: Molecules (Basel, Switzerland) [Molecules] 2024 Oct 13; Vol. 29 (20). Date of Electronic Publication: 2024 Oct 13.
DOI: 10.3390/molecules29204847
Abstrakt: The operation of bacteriorhodopsin ( BR ) from the archaeon Halobacterium salinarum is based on the photochromic reaction of isomerization of the chromophore group (the retinal protonated Schiff base, RPSB) from the all- trans to the 13- cis form. The ultrafast dynamics of the reverse 13- cis → all- trans photoreaction was studied using femtosecond transient absorption spectroscopy in comparison with the forward photoreaction. The forward photoreaction was initiated by photoexcitation of BR by pulse I (540 nm). The reverse photoreaction was initiated by photoexcitation of the product K 590 at an early stage of its formation (5 ps) by pulse II (660 nm). The conversion of the excited K 590 to the ground state proceeds at times of 0.19, 1.1, and 16 ps with the relative contributions of ~20/60/20, respectively. All these decay channels lead to the formation of the initial state of BR as a product with a quantum yield of ~1. This state is preceded by vibrationally excited intermediates, the relaxation of which occurs in the 16 ps time range. Likely, the heterogeneity of the excited state of K 590 is determined by the heterogeneity of its chromophore center. The forward photoreaction includes two components-0.52 and 3.5 ps, with the relative contributions of 91/9, respectively. The reverse photoreaction initiated from K 590 proceeds more efficiently in the conical intersection (CI) region but on the whole at a lower rate compared to the forward photoreaction, due to significant heterogeneity of the potential energy surface.
Databáze: MEDLINE
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