Structural basis for the emission of violet bioluminescence from a W92F obelin mutant

FEBS Letters

Liu, Zhi-Jie²  Lee, John²  Rose, John²  Wang, Bi-Cheng²  Vysotski, Eugene S.¹  Deng, Lu³  Malikova, Natalia P.¹  Markova, Svetlana V.¹ 

[1] Photobiology Laboratory, Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036, Russia;Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA;Department of Chemistry, University of Georgia, Athens, GA 30602, USA

关键词: Calcium-regulated photoprotein;    X-ray crystallography;    Fluorescence;    Coelenterazine;    Aequorin;    WT obelin;    recombinant Ca2+-regulated photoprotein from Obelia longissima;   

DOI  :  10.1016/S0014-5793(01)02937-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Mutation of the Trp92 that is known to lie within the active site of the photoprotein obelin from Obelia longissima, results in a shift of the bioluminescence color from blue (λ _max=485 nm) to violet. The corrected spectrum shows a new band with λ _max=410 nm now contributing equally to the one at longer wavelength. The crystal structure of this W92F obelin determined at 1.72 Å resolution shows that there is no significant change in the dimensions of the active site between WT obelin (recombinant Ca²⁺-regulated photoprotein from Obelia longissima) and the mutant. It is proposed that the bioluminescence spectral shift results from removal of a hydrogen bond from the indole of W92 nearby a hydroxyl belonging to the 6-phenyl substituent of the substrate coelenterazine. Propagation of this change through a conjugated bond system in the excited state of the product coelenteramide affects the coupling of the N1-position and the hydrogen-bonded Y138.

【 授权许可】

Unknown