All Ca(2+)-binding loops of light-sensitive ctenophore photoprotein berovin bind magnesium ions: The spatial structure of Mg(2+)-loaded apo-berovin.

Autor: Burakova LP; Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650500, China; Photobiology Laboratory, Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Akademgorodok 50, Bldg. 50, Krasnoyarsk 660036, Russia; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China., Natashin PV; Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650500, China; Photobiology Laboratory, Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Akademgorodok 50, Bldg. 50, Krasnoyarsk 660036, Russia; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China., Malikova NP; Photobiology Laboratory, Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Akademgorodok 50, Bldg. 50, Krasnoyarsk 660036, Russia., Niu F; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; iHuman Institute, ShanghaiTech University, 99 Haike Road, Shanghai 201210, China., Pu M; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China., Vysotski ES; Photobiology Laboratory, Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Akademgorodok 50, Bldg. 50, Krasnoyarsk 660036, Russia. Electronic address: eugene.vysotski@gmail.com., Liu ZJ; Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650500, China; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; iHuman Institute, ShanghaiTech University, 99 Haike Road, Shanghai 201210, China. Electronic address: liuzhj@shanghaitech.edu.cn.
Jazyk: angličtina
Zdroj: Journal of photochemistry and photobiology. B, Biology [J Photochem Photobiol B] 2016 Jan; Vol. 154, pp. 57-66. Date of Electronic Publication: 2015 Dec 02.
DOI: 10.1016/j.jphotobiol.2015.11.012
Abstrakt: Light-sensitive photoprotein berovin accounts for a bright bioluminescence of ctenophore Beroe abyssicola. Berovin is functionally identical to the well-studied Ca(2+)-regulated photoproteins of jellyfish, however in contrast to those it is extremely sensitive to the visible light. Berovin contains three EF-hand Ca(2+)-binding sites and consequently belongs to a large family of the EF-hand Ca(2+)-binding proteins. Here we report the spatial structure of apo-berovin with bound Mg(2+) determined at 1.75Å. The magnesium ion is found in each functional EF-hand loop of a photoprotein and coordinated by oxygen atoms donated by the side-chain groups of aspartate, carbonyl groups of the peptide backbone, or hydroxyl group of serine with characteristic oxygen-Mg(2+) distances. As oxygen supplied by the side-chain of the twelfth residue of all Ca(2+)-binding loops participates in the magnesium ion coordination, it was suggested that Ca(2+)-binding loops of berovin belong to the mixed Ca(2+)/Mg(2+) rather than Ca(2+)-specific type. In addition, we report an effect of physiological concentration of Mg(2+) on bioluminescence of berovin (sensitivity to Ca(2+), rapid-mixed kinetics, light-sensitivity, thermostability, and apo-berovin conversion into active protein). The different impact of physiological concentration of Mg(2+) on berovin bioluminescence as compared to hydromedusan photoproteins was attributed to different affinities of the Ca(2+)-binding sites of these photoproteins to Mg(2+).
(Copyright © 2015 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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