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Your query returned 2 entries. Printable version
EC | 1.13.12.5 | ||||||||||||||
Accepted name: | Renilla-type luciferase | ||||||||||||||
Reaction: | coelenterazine h + O2 = excited coelenteramide h monoanion + CO2 (over-all reaction) (1a) coelenterazine h + O2 = coelenterazine h dioxetanone (1b) coelenterazine h dioxetanone = excited coelenteramide h monoanion + CO2 |
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For diagram of reaction, click here | |||||||||||||||
Glossary: | coelenterazine h = Renilla luciferin = 2,8-dibenzyl-6-(4-hydroxyphenyl)imidazo[1,2-a]pyrazin-3(7H)-one coelenteramide h = Renilla oxyluciferin = N-[3-benzyl-5-(4-hydroxyphenyl)pyrazin-2-yl]-2-phenylacetamide |
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Other name(s): | Renilla-luciferin 2-monooxygenase; luciferase (Renilla luciferin); Renilla-luciferin:oxygen 2-oxidoreductase (decarboxylating) | ||||||||||||||
Systematic name: | coelenterazine h:oxygen 2-oxidoreductase (decarboxylating) | ||||||||||||||
Comments: | This enzyme has been studied from the soft coral Renilla reniformis. Before the reaction occurs the substrate is sequestered by a coelenterazine-binding protein. Elevation in the concentration of calcium ions releases the substrate, which then interacts with the luciferase. Upon binding the substrate, the enzyme catalyses an oxygenation, producing a very short-lived hydroperoxide that cyclizes into a dioxetanone structure, which collapses, releasing a CO2 molecule. The spontaneous breakdown of the dioxetanone releases the energy (about 50 kcal/mole) that is necessary to generate the excited state of the coelenteramide product, which is the singlet form of the monoanion. In vivo the product undergoes the process of nonradiative energy transfer to an accessory protein, a green fluorescent protein (GFP), which results in green bioluminescence. In vitro, in the absence of GFP, the product emits blue light. | ||||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 61869-41-8 | ||||||||||||||
References: |
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EC | 1.13.12.24 | ||||||||||||||
Accepted name: | calcium-regulated photoprotein | ||||||||||||||
Reaction: | [apoaequorin] + coelenterazine + O2 + 3 Ca2+ = [excited state blue fluorescent protein] + CO2 (overall reaction) (1a) [apoaequorin] + coelenterazine = [apoaequorin containing coelenterazine] (1b) [apoaequorin containing coelenterazine] + O2 = [aequorin] (1c) [aequorin] + 3 Ca2+ = [aequorin] 1,2-dioxetan-3-one (1d) [aequorin] 1,2-dioxetan-3-one = [excited state blue fluorescent protein] + CO2 |
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Glossary: | coelenterazine = 8-benzyl-2-(4-hydroxybenzyl)-6-(4-hydroxyphenyl)imidazo[1,2-a]pyrazin-3(7H)-one coelenteramide = N-[3-benzyl-5-(4-hydroxyphenyl)pyrazin-2-yl]-2-(4-hydroxyphenyl)acetamide aequorin = the non-covalent complex formed by apoaequorin polypeptide and coelenterazine-2-hydroperoxide. blue fluorescent protein = the non-covalent complex formed by Ca2+-bound apoaequorin polypeptide and coelenteramide |
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Other name(s): | Ca2+-regulated photoprotein; calcium-activated photoprotein; aequorin; obelin; halistaurin; mitrocomin; phialidin; clytin; mnemiopsin; berovin | ||||||||||||||
Systematic name: | coelenterazine:oxygen 2-oxidoreductase (decarboxylating, calcium-dependent) | ||||||||||||||
Comments: | Ca2+-regulated photoproteins are found in a variety of bioluminescent marine organisms, mostly coelenterates, and are responsible for their light emission. The best studied enzyme is from the jellyfish Aequorea victoria. The enzyme tightly binds the imidazolopyrazinone derivative coelenterazine, which is then peroxidized by oxygen. The hydroperoxide is stably bound until three Ca2+ ions bind to the protein, inducing a structural change that results in the formation of a 1,2-dioxetan-3-one ring, followed by decarboxylation and generation of a protein-bound coelenteramide in an excited state. The calcium-bound protein-product complex is known as a blue fluorescent protein. In vivo the energy is transferred to a green fluorescent protein (GFP) by Förster resonance energy transfer. In vitro, in the absence of GFP, coelenteramide emits a photon of blue light while returning to its ground state. | ||||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||||
References: |
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