Biomaterial Database

Purification and properties of a NAD(P)H:flavin oxidoreductase from the luminous bacterium, Beneckea harveyi. 1977

G A Michaliszyn, and S S Wing, and E A Meighen

A NAD(P)H:flavin oxidoreductase, which produces FMNH2, one of the substrates for the luciferase reaction in bioluminescent bacteria, has been purified with the aid of affinity chromatography on epsilon-aminohexanoyl-FMN-Sepharose. The purified enzyme, isolated from Beneckea harveyi, had a specific activity of 89 mumol of NADH oxidized/min/mg of protein at 23 degrees in the presence of saturating FMN and NADH and appeared homogeneous by several criteria on polyacrylamide gel electrophoresis. A molecular weight of 24,000 was estimated both by gel filtration and and sodium dodecyl sulfate gel electrophoresis indicating that the enzyme is composed of a single polypeptide chain. Kinetic studies showed that the higher specificity of the enzyme for NADH than NADPH and for riboflavin and FMN than FAD was primarily due to variations in the Michaelis constants for the different substrates. Initial velocity studies with all pairs of substrates gave intersecting patterns supporting a sequential mechanism for the NAD(P)H:flavin oxidoreductase.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009247	NADH, NADPH Oxidoreductases	A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.	Oxidoreductases, NADH, NADPH,NADPH Oxidoreductases NADH,Oxidoreductases NADH, NADPH
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
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities
D014733	Vibrio	A genus of VIBRIONACEAE, made up of short, slightly curved, motile, gram-negative rods. Various species produce cholera and other gastrointestinal disorders as well as abortion in sheep and cattle.	Beneckea
D014737	Vibrionaceae	A family of gram-negative bacteria whose members predominate in the bacterial flora of PLANKTON; FISHES; and SEAWATER. Some members are important pathogens for humans and animals.
D046911	Macromolecular Substances	Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.	Macromolecular Complexes,Macromolecular Compounds,Macromolecular Compounds and Complexes,Complexes, Macromolecular,Compounds, Macromolecular,Substances, Macromolecular