ENZYME - 1.13.12.5 Renilla-type luciferase

• 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 catalyzes 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.

P27652, LUCI_RENRE