Biomaterial Database

Studies on luciferase from Photobacterium phosphoreum. VIII. FMN-H2O2 initiated bioluminescence and the thermodynamics of the elementary steps of the luciferase reaction. 1976

T Watanabe, and T Nakamura

Bacterial luciferase from Photobacterium phosohoreum was found to produce bioluminescence on reaction with FMN and H2O2 in the presence of aldehyde. This luminescence is presumably produced by the same X1 intermediate as that found in FMNH2-O2 initiated luminescence. From the ratio of the light intensities of the FMN-H2O2 initiated reactions, we calculated the association constant of the reaction, luciferase+FMN+H2O2in equilibriumX1, and estimated its temperature dependence. From these results we calculated the thermodynamic parameters of the reaction, luciferase+FMNH2+O2in equilibriumX1. We found that the free energy level of X1 is only 3.2 kcal below that of fr-e FMN and H2O2. We also estimated the thermodynamic parameters of other steps of the luminescent reaction. The values obtained showed that the formation of X1 from luciferase, FMNH2 and O2 involves a positive entropy change, but the intermediate is in a state stabilized against decomposition. Results also suggest a considerable degree of electronic rearrangement on formation of the excited-state molecule from the X1-aldehyde complex.

UI	MeSH Term	Description	Entries
D008156	Luciferases	Enzymes that oxidize certain LUMINESCENT AGENTS to emit light (PHYSICAL LUMINESCENCE). The luciferases from different organisms have evolved differently so have different structures and substrates.	Luciferase
D008163	Luminescent Measurements	Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.	Bioluminescence Measurements,Bioluminescent Assays,Bioluminescent Measurements,Chemiluminescence Measurements,Chemiluminescent Assays,Chemiluminescent Measurements,Chemoluminescence Measurements,Luminescence Measurements,Luminescent Assays,Luminescent Techniques,Phosphorescence Measurements,Phosphorescent Assays,Phosphorescent Measurements,Assay, Bioluminescent,Assay, Chemiluminescent,Assay, Luminescent,Assay, Phosphorescent,Assays, Bioluminescent,Assays, Chemiluminescent,Assays, Luminescent,Assays, Phosphorescent,Bioluminescence Measurement,Bioluminescent Assay,Bioluminescent Measurement,Chemiluminescence Measurement,Chemiluminescent Assay,Chemiluminescent Measurement,Chemoluminescence Measurement,Luminescence Measurement,Luminescent Assay,Luminescent Measurement,Luminescent Technique,Measurement, Bioluminescence,Measurement, Bioluminescent,Measurement, Chemiluminescence,Measurement, Chemiluminescent,Measurement, Chemoluminescence,Measurement, Luminescence,Measurement, Luminescent,Measurement, Phosphorescence,Measurement, Phosphorescent,Measurements, Bioluminescence,Measurements, Bioluminescent,Measurements, Chemiluminescence,Measurements, Chemiluminescent,Measurements, Chemoluminescence,Measurements, Luminescence,Measurements, Luminescent,Measurements, Phosphorescence,Measurements, Phosphorescent,Phosphorescence Measurement,Phosphorescent Assay,Phosphorescent Measurement,Technique, Luminescent,Techniques, Luminescent
D010776	Photobacterium	A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that are common in the marine environment and on the surfaces and in the intestinal contents of marine animals. Some species are bioluminescent and are found as symbionts in specialized luminous organs of fish.
D005486	Flavin Mononucleotide	A coenzyme for a number of oxidative enzymes including NADH DEHYDROGENASE. It is the principal form in which RIBOFLAVIN is found in cells and tissues.	FMN,Flavin Mononucleotide Disodium Salt,Flavin Mononucleotide Monosodium Salt,Flavin Mononucleotide Monosodium Salt, Dihydrate,Flavin Mononucleotide Sodium Salt,Riboflavin 5'-Monophosphate,Riboflavin 5'-Phosphate,Riboflavin Mononucleotide,Sodium Riboflavin Phosphate,5'-Monophosphate, Riboflavin,5'-Phosphate, Riboflavin,Mononucleotide, Flavin,Mononucleotide, Riboflavin,Phosphate, Sodium Riboflavin,Riboflavin 5' Monophosphate,Riboflavin 5' Phosphate,Riboflavin Phosphate, Sodium
D006861	Hydrogen Peroxide	A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.	Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D000447	Aldehydes	Organic compounds containing a carbonyl group in the form -CHO.	Aldehyde
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D013816	Thermodynamics	A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)	Thermodynamic