Тип публикации: статья из журнала
Год издания: 2013
Идентификатор DOI: 10.1002/cbic.201300002
Ключевые слова: aequorin, coelenterazine, luminescence, photoprotein, protein folding, anion, apoprotein, calcium ion, histidine, oxygen, proton, pyrazine derivative, unclassified drug, absorption spectroscopy, air, article, bioluminescence, biotransformation, kinetics, pH, priority journal, proton transport, Animals, Calcium, Hydrozoa, Imidazoles, Luminescent Proteins, Models, Molecular, Protein Binding, Protons, Pyrazines, Spectrophotometry
Аннотация: 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-obelincoelenteПоказать полностьюrazine 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.
Журнал: CHEMBIOCHEM
Выпуск журнала: Vol. 14, Is. 6
Номера страниц: 739-745
ISSN журнала: 14394227
Место издания: WEINHEIM
Издатель: WILEY-V C H VERLAG GMBH