Luciferase is a generic term for the class of oxidative enzymes that produce bioluminescence, and is usually distinguished from a photoprotein. The name was first used by Raphaël Dubois who invented the words luciferin and luciferase, for the substrate and enzyme, respectively. Both words are derived from the Latin word lucifer - meaning lightbringer.
luciferase is present mostly in.
1 Firefly and click beetle
2 Copepod
3 Sea pansy
4 Bacterial
5 Dinoflagellate
Luciferases are widely used in biotechnology, for microscopy and as reporter genes, for many of the same applications as fluorescent proteins. However, unlike fluorescent proteins, luciferases do not require an external light source, but do require addition of luciferin, the consumable substrate.
Mechanism of reaction
All luciferases are classified as oxidoreductases (EC 1.13.12.-), meaning they act on single donors with incorporation of molecular oxygen. Because luciferases are from many diverse protein families that are unrelated, there is no unifying mechanism, as any mechanism depends on the luciferase and luciferin combination. However, all characterised luciferase-luciferin reactions to date have been shown to require molecular oxygen at some stage.
The reaction catalyzed by bacterial luciferase is also an oxidative process:
FMNH2 + O2 + RCHO → FMN + RCOOH + H2O + light
In the reaction, a reduced flavin mononucleotide oxidizes a long-chain aliphatic aldehyde to an aliphatic carboxylic acid. The reaction forms an excited hydroxyflavin intermediate, which is dehydrated to the product FMN to emit blue-green light.[8]
Nearly all of the energy input into the reaction is transformed into light. The reaction is 80%[9] to 90%[10] efficient. As a comparison, the incandescent light bulb only converts about 10% of its energy into light.[11] and a 150 lumen per Watt (lm/W) LED converts 20% of input energy to visible light.