Cypridina bioluminescence VII. chemiluminescence in micelle solutions — a model system for cypridina bioluminescence
✍ Scribed by Toshio Goto; Hiroshi Fukatsu
- Publisher
- Elsevier Science
- Year
- 1969
- Tongue
- French
- Weight
- 232 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0040-4039
No coin nor oath required. For personal study only.
✦ Synopsis
Cypridina bioluminescence is produced in aqueous solution by oxidation of Cypridina luciferin (substrate) with molecular oxygen in the presence of Cypridina luciferase (enzyme), which may be classified as one of the dioxygenases (1). Luciferin also chemiluminesces strongly in aprotic solvents such as diglyme or DMSO without enzyme (Z), and the mechanism of the bioluminescence is assumed to be identical with that of the chemiluminescence with the exception that luciferin does not produce light in aqueous solution without enzyme (3,4). We have assumed (3) that the role of the enzyme would be simply to give luciferin a suitable hydrophobic environment (5), which may be expected to be in a cave of the enzyme; luciferin (I) then reacts spontaneously with molecular oxygen to produce oxyluciferin (II) in a singlet Rl 02 l + COn + hv Rl I, III, v II, IV I and II: ~~ = 3-indolyl, RP = -(cH~)~NHC(=NH)NH~, R3 = -cH(cH3)cH2cH3 III and IV: Rl = phenyl, RZ = H, R3 = CH3 V: R1 = 3-indolyl, RZ = H, R3 = CH3 excited state, which then gives light. If this assumption is true, major roles of the enzyme would be: [a) enhancement of fluorescence intensity of oxyluciferin (II) and (b) enhancement of reaction rate of luciferin (I) with molecular oxygen. These are verified by the following observations. In the case of bioluminescence, the fluorescence quantum yield of oxyluciferin must be high, since the bioluminescence quantum yield is high (6), and the luminescence spec-