Oxygen activation of apo-obelin-coelenterazine complex
| Autor: | Yuguang Zhou, Lei Song, Elena V. Eremeeva, Eugene S. Vysotski, Zhi-Jie Liu, Pavel V. Natashin, Willem J. H. van Berkel |
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| Rok vydání: | 2013 |
| Předmět: |
Models
Molecular Luminescence Kinetics Aequorin Photoprotein Biochemie aequorin chemistry.chemical_element Protonation Photochemistry Biochemistry Oxygen chemistry.chemical_compound Residue (chemistry) ca2+-discharged photoprotein molecular-oxygen Coelenterazine angstrom resolution Bioluminescence Animals Histidine Molecular Biology recombinant obelin VLAG calcium biology green-fluorescent protein Organic Chemistry Imidazoles crystal-structure bioluminescence jellyfish clytia-gregaria Luminescent Proteins Hydrozoa chemistry Spectrophotometry Pyrazines biology.protein Molecular Medicine Calcium Protons Protein Binding |
| Zdroj: | ChemBioChem 14 (2013) 6 ChemBioChem, 14(6), 739-745 |
| ISSN: | 1439-7633 1439-4227 |
| Popis: | Ca(2+) -regulated photoproteins use a noncovalently bound 2-hydroperoxycoelenterazine ligand to emit light in response to Ca(2+) 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 Ca(2+) -triggering of the bioluminescence reaction. |
| Databáze: | OpenAIRE |
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