Biomaterial Database

Purification and properties of ornithine decarboxylase from Lactobacillus sp. 30a. 1980

B M Guirard, and E E Snell

Inducible ornithine decarboxylase from Lactobacillus sp. 30a has been purified to homogeneity as judged by ultracentrifugation and gel electrophoresis. Unlike histidine decarboxylase from the same species (a pyruvoyl enzyme), ornithine decarboxylase is a pyridoxal phosphate enzyme. The purified enzyme is specific for L-pornithine (Km 1.7 mM; specific activity, 150 to 200 mumol min-1 mg-1 at 37 degrees C) and is inhibited by various homologous omega-amino acids, amines, and polyamines. The native enzyme has an isoelectric point of 4.55 and a molecular weight of 1.04 X 10(6). At pH 7.3 and above, it dissociates reversibly to a species of Mr = 184,000, and on gel electrophoresis in the presence of sodium dodecyl sulfate shows a single band of Mr = 85,000. We ascribe these species to the dodecamer, dimer, and monomer, respectively, of a single peptide subunit; electron micrographs show a hexagonal array of apparently dimeric subunits in the native enzyme. Highest enzymatic activity is present in the dodecamer. The holoenzyme is resolved by dialysis against cysteine; spectrophotoemetric titration of the apoenzyme with pyridoxal 5'-phosphate indicates the presence of 1 coenzyme-binding site/monomeric subunit.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007778	Lactobacillus	A genus of gram-positive, microaerophilic, rod-shaped bacteria occurring widely in nature. Its species are also part of the many normal flora of the mouth, intestinal tract, and vagina of many mammals, including humans. Lactobacillus species are homofermentative and ferment a broad spectrum of carbohydrates often host-adapted but do not ferment PENTOSES. Most members were previously assigned to the Lactobacillus delbrueckii group. Pathogenicity from this genus is rare.
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009955	Ornithine Decarboxylase	A pyridoxal-phosphate protein, believed to be the rate-limiting compound in the biosynthesis of polyamines. It catalyzes the decarboxylation of ornithine to form putrescine, which is then linked to a propylamine moiety of decarboxylated S-adenosylmethionine to form spermidine.	Ornithine Carboxy-lyase,Carboxy-lyase, Ornithine,Decarboxylase, Ornithine,Ornithine Carboxy lyase
D002262	Carboxy-Lyases	Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.	Carboxy-Lyase,Decarboxylase,Decarboxylases,Carboxy Lyase,Carboxy Lyases
D003460	Crystallization	The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Crystalline Polymorphs,Polymorphism, Crystallization,Crystal Growth,Polymorphic Crystals,Crystal, Polymorphic,Crystalline Polymorph,Crystallization Polymorphism,Crystallization Polymorphisms,Crystals, Polymorphic,Growth, Crystal,Polymorph, Crystalline,Polymorphic Crystal,Polymorphisms, Crystallization,Polymorphs, Crystalline
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
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