Biomaterial Database

Extracellular tyrosinase from Streptomyces sp. KY-453: purification and some enzymatic properties. 1985

T Yoshimoto, and K Yamamoto, and D Tsuru

A strain of Streptomyces isolated from soil was found to produce a large amount of tyrosinase (monophenol, dihydroxy-L-phenylalanine: oxygen oxidoreductase: EC 1.14.18.1) extracellularly. The enzyme was purified from the culture filtrate about 550-fold by a series of column chromatographies on Duolite A-2 and CM-cellulose and gel filtration on Sephadex G-100. The purified enzyme appeared homogeneous as judged by disc gel electrophoresis. The enzyme catalyzed the hydroxylation of monophenols and the oxidation of diphenols and was most active at pH 6.8 with dihydroxy-L-phenylalanine (L-DOPA) as the substrate. It was inhibited by kojic acid, diethyldithiocarbamate, and inhibitors obtained from micro-organisms. The isoelectric point of the enzyme was 9.9, and the molecular weight was estimated to be 36,000 by gel filtration on Sephadex G-100 and 29,000 by sodium dodecyl sulfate (SDS) gel electrophoresis, which suggests that the enzyme is a monomer. Metal analysis by atomic absorption spectroscopy indicated that the enzyme contains nearly 1 gram atom of copper per mol.

UI	MeSH Term	Description	Entries
D007526	Isoelectric Point	The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.	Isoelectric Points,Point, Isoelectric,Points, Isoelectric
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008670	Metals	Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metal
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
D003300	Copper	A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.	Copper-63,Copper 63
D004156	Catechol Oxidase	An enzyme of the oxidoreductase class that catalyzes the reaction between catechol and oxygen to yield benzoquinone and water. It is a complex of copper-containing proteins that acts also on a variety of substituted catechols. EC 1.10.3.1.	Diphenol Oxidases,Diphenol Oxidase,Polyphenol Oxidase,Polyphenoloxidase,Oxidase, Catechol,Oxidase, Diphenol,Oxidase, Polyphenol,Oxidases, Diphenol
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D012988	Soil Microbiology	The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.	Microbiology, Soil
D013302	Streptomyces	A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.