Biomaterial Database

Microheterogeneity of melanosome-bound tyrosinase from the Harding-Passey murine melanoma. 1987

U Ferrini, and A M Mileo, and V J Hearing

This study was directed towards the characterization of the origin of the microheterogeneity displayed by mammalian tyrosinase, the enzyme responsible for pigmentation in mammals. Tyrosinase was purified from the Harding Passey murine melanoma, fractionated into a continuous series of subisozymic forms, and analyzed using various chemical and immunological probes. Treatment with neuraminidase revealed that all the forms had similar amounts of sialic acid, and reactivity with various carbohydrate specific lectins showed that the isozymes also contained subterminal galactose, N-acetylglucosamine, and mannose, but lacked alpha-fucose. Amino acid composition data indicated that the polypeptides of all the forms had identical residue contents. The sum of the evidence further supports the theory that the isozymic forms demonstrable for mammalian tyrosinase represent intermediate processing stages of the enzyme from the nascent protein chain to the fully glycosylated, high molecular weight form of tyrosinase that is localized within melanin granules.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D008544	Melanocytes	Mammalian pigment cells that produce MELANINS, pigments found mainly in the EPIDERMIS, but also in the eyes and the hair, by a process called melanogenesis. Coloration can be altered by the number of melanocytes or the amount of pigment produced and stored in the organelles called MELANOSOMES. The large non-mammalian melanin-containing cells are called MELANOPHORES.	Melanocyte
D008546	Melanoma, Experimental	Experimentally induced tumor that produces MELANIN in animals to provide a model for studying human MELANOMA.	B16 Melanoma,Melanoma, B16,Melanoma, Cloudman S91,Melanoma, Harding-Passey,Experimental Melanoma,Experimental Melanomas,Harding Passey Melanoma,Melanomas, Experimental,B16 Melanomas,Cloudman S91 Melanoma,Harding-Passey Melanoma,Melanoma, Harding Passey,Melanomas, B16,S91 Melanoma, Cloudman
D008807	Mice, Inbred BALB C	An inbred strain of mouse that is widely used in IMMUNOLOGY studies and cancer research.	BALB C Mice, Inbred,BALB C Mouse, Inbred,Inbred BALB C Mice,Inbred BALB C Mouse,Mice, BALB C,Mouse, BALB C,Mouse, Inbred BALB C,BALB C Mice,BALB C Mouse
D009439	Neuraminidase	An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992)	Sialidase,Exo-alpha-Sialidase,N-Acylneuraminate Glycohydrolases,Oligosaccharide Sialidase,Exo alpha Sialidase,Glycohydrolases, N-Acylneuraminate,N Acylneuraminate Glycohydrolases,Sialidase, Oligosaccharide
D002241	Carbohydrates	A class of organic compounds composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n. The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES.	Carbohydrate
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
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014442	Monophenol Monooxygenase	An enzyme of the oxidoreductase class that catalyzes the reaction between L-tyrosine, L-dopa, and oxygen to yield L-dopa, dopaquinone, and water. It is a copper protein that acts also on catechols, catalyzing some of the same reactions as CATECHOL OXIDASE. EC 1.14.18.1.	Dopa Oxidase,Phenoloxidase,Tyrosinase,Cresolase,Phenol Oxidase,Phenoloxidase A,Phenoloxidase B,Monooxygenase, Monophenol,Oxidase, Dopa,Oxidase, Phenol