These authors contributed equally to this work.
Oxygen Activation of Apo-obelin–Coelenterazine Complex
Article first published online: 12 MAR 2013
Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Volume 14, Issue 6, pages 739–745, April 15, 2013
How to Cite
Eremeeva, E. V., Natashin, P. V., Song, L., Zhou, Y., van Berkel, W. J. H., Liu, Z.-J. and Vysotski, E. S. (2013), Oxygen Activation of Apo-obelin–Coelenterazine Complex. ChemBioChem, 14: 739–745. doi: 10.1002/cbic.201300002
- Issue published online: 8 APR 2013
- Article first published online: 12 MAR 2013
- Manuscript Received: 1 JAN 2013
- RFBR. Grant Number: 12-04-91153
- NSFC. Grant Numbers: 31270795, 31021062
- Russian Federation Government Program “Measures to Attract Leading Scientists to Russian Educational Institutions”. Grant Number: 11.G34.31.0058
- “Molecular and Cellular Biology” of RAS, President of the Russian Federation “Leading Science School”. Grant Number: 1044.2012.2
- protein folding
Ca2+-regulated photoproteins use a noncovalently bound 2-hydroperoxycoelenterazine ligand to emit light in response to Ca2+ binding. To better understand the mechanism of formation of active photoprotein from apoprotein, coelenterazine and molecular oxygen, we investigated the spectral properties of the anaerobic apo-obelin–coelenterazine complex and the kinetics of its conversion into active photoprotein after exposure to air. Our studies suggest that coelenterazine bound within the anaerobic complex might be a mixture of N7-protonated and C2(−) anionic forms, and that oxygen shifts the equilibrium in favor of the C2(−) anion as a result of peroxy anion formation. Proton removal from N7 and further protonation of peroxy anion and the resulting formation of 2-hydroperoxycoelenterazine in obelin might occur with the assistance of His175. It is proposed that this conserved His residue might play a key role both in formation of active photoprotein and in Ca2+-triggering of the bioluminescence reaction.