Comparative Femtosecond Spectroscopy of Primary Photoreactions of Exiguobacterium sibiricum Rhodopsin and Halobacterium salinarum Bacteriorhodopsin
| Autor: | M. A. Yakovleva, Mikhail A. Ostrovsky, Oksana V. Nekrasova, Victor A. Nadtochenko, Dmitry A. Cherepanov, Fedor E. Gostev, Ivan V. Shelaev, Irina B. Kolchugina, Lada E. Petrovskaya, T. B. Feldman, Dmitry A. Dolgikh, O. A. Smitienko, Mikhail P. Kirpichnikov |
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| Rok vydání: | 2021 |
| Předmět: |
010304 chemical physics
biology Photoisomerization Retinal Bacteriorhodopsin 010402 general chemistry Photochemistry biology.organism_classification 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films symbols.namesake chemistry.chemical_compound chemistry Rhodopsin Stokes shift 0103 physical sciences Femtosecond Materials Chemistry biology.protein symbols Halobacterium salinarum Physical and Theoretical Chemistry Femtochemistry |
| Zdroj: | The Journal of Physical Chemistry B. 125:995-1008 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/acs.jpcb.0c07763 |
| Popis: | The primary stages of the Exiguobacterium sibiricum rhodopsin (ESR) photocycle were investigated by femtosecond absorption laser spectroscopy in the spectral range of 400-900 nm with a time resolution of 25 fs. The dynamics of the ESR photoreaction were compared with the reactions of bacteriorhodopsin (bR) in purple membranes (bRPM) and in recombinant form (bRrec). The primary intermediates of the ESR photocycle were similar to intermediates I, J, and K in bacteriorhodopsin photoconversion. The CONTIN program was applied to analyze the characteristic times of the observed processes and to clarify the reaction scheme. A similar photoreaction pattern was observed for all studied retinal proteins, including two consecutive dynamic Stokes shift phases lasting ∼0.05 and ∼0.15 ps. The excited state decays through a femtosecond reactive pathway, leading to retinal isomerization and formation of product J, and a picosecond nonreactive pathway that leads only to the initial state. Retinal photoisomerization in ESR takes 0.69 ps, compared with 0.48 ps in bRPM and 0.74 ps in bRrec. The nonreactive excited state decay takes 5 ps in ESR and ∼3 ps in bR. We discuss the similarity of the primary reactions of ESR and other retinal proteins. |
| Databáze: | OpenAIRE |
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