Unusual shift in the visible absorption spectrum of an active ctenophore photoprotein elucidated by time-dependent density functional theory.

Autor: Tomilin FN; Kirensky Institute of Physics SB RAS, Federal Research Center 'Krasnoyarsk Science Center SB RAS', Akademgorodok 50/38, Krasnoyarsk, 660036, Russia.; Siberian Federal University, Svobodny 79 pr., Krasnoyarsk, 660041, Russia.; National Research Tomsk State University, Lenin Avenue 36, Tomsk, 634050, Russia., Rogova AV; Siberian Federal University, Svobodny 79 pr., Krasnoyarsk, 660041, Russia., Burakova LP; Siberian Federal University, Svobodny 79 pr., Krasnoyarsk, 660041, Russia.; Photobiology Laboratory, Institute of Biophysics SB RAS, Federal Research Center 'Krasnoyarsk Science Center SB RAS', Akademgorodok 50/50, Krasnoyarsk, 660036, Russia., Tchaikovskaya ON; National Research Tomsk State University, Lenin Avenue 36, Tomsk, 634050, Russia., Avramov PV; Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, South Korea., Fedorov DG; Research Center for Computational Design of Advanced Functional Materials (CD-FMat), National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba, 305-8568, Japan. d.g.fedorov@aist.go.jp., Vysotski ES; Photobiology Laboratory, Institute of Biophysics SB RAS, Federal Research Center 'Krasnoyarsk Science Center SB RAS', Akademgorodok 50/50, Krasnoyarsk, 660036, Russia. eugene.vysotski@gmail.com.
Jazyk: angličtina
Zdroj: Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology [Photochem Photobiol Sci] 2021 Apr 08. Date of Electronic Publication: 2021 Apr 08.
DOI: 10.1007/s43630-021-00039-5
Abstrakt: Active hydromedusan and ctenophore Ca 2+ -regulated photoproteins form complexes consisting of apoprotein and strongly non-covalently bound 2-hydroperoxycoelenterazine (an oxygenated intermediate of coelenterazine). Whereas the absorption maximum of hydromedusan photoproteins is at 460-470 nm, ctenophore photoproteins absorb at 437 nm. Finding out a physical reason for this blue shift is the main objective of this work, and, to achieve it, the whole structure of the protein-substrate complex was optimized using a linear scaling quantum-mechanical method. Electronic excitations pertinent to the spectra of the 2-hydroperoxy adduct of coelenterazine were simulated with time-dependent density functional theory. The dihedral angle of 60° of the 6-(p-hydroxy)-phenyl group relative to the imidazopyrazinone core of 2-hydroperoxycoelenterazine molecule was found to be the key factor determining the absorption of ctenophore photoproteins at 437 nm. The residues relevant to binding of the substrate and its adopting the particular rotation were also identified.
Databáze: MEDLINE
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