Biomaterial Database

Purification of a human cytochrome P-450 isozyme catalyzing lanosterol 14 alpha-demethylation. 1993

Y Sonoda, and M Endo, and K Ishida, and Y Sato, and N Fukusen, and M Fukuhara

Kyoritsu College of Pharmacy, Tokyo, Japan.

An isozyme of cytochrome P-450 catalyzing lanosterol 14 alpha-demethylation was purified from human liver using column chromatography, including immunoaffinity chromatography. The purified protein exhibited a single protein band (53 kDa) on sodium dodecylsulfate-polyacrylamide gel electrophoresis. When reconstituted with NADPH-cytochrome P-450 reductase, the purified protein showed an activity of 14 alpha-demethylation of 24,25-dihydrolanosterol (3.20 nmol/min per mg protein). The apparent Km value for 24,25-dihydrolanosterol was found to be 27 microM. This enzyme converted in the reconstituted system, the oxygenated intermediates of 24,25-dihydrolanosterol 14 alpha-demethylation, 32-hydroxy-24,25-dihydrolanosterol and 32-oxo-24,25-dihydrolanosterol, to the 32-nor compound, 4,4-dimethylcholesta-8,14-dien-3 beta-ol.

UI	MeSH Term	Description	Entries
D007810	Lanosterol	A triterpene that derives from the chair-boat-chair-boat folding of 2,3-oxidosqualene. It is metabolized to CHOLESTEROL and CUCURBITACINS.	Kryptosterol,4,4,14 alpha-trimethyl-5 alpha-cholesta-8,24-dien-3 beta-ol
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D010088	Oxidoreductases	The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)	Dehydrogenases,Oxidases,Oxidoreductase,Reductases,Dehydrogenase,Oxidase,Reductase
D003429	Cross Reactions	Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.	Cross Reaction,Reaction, Cross,Reactions, Cross
D003577	Cytochrome P-450 Enzyme System	A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.	Cytochrome P-450,Cytochrome P-450 Enzyme,Cytochrome P-450-Dependent Monooxygenase,P-450 Enzyme,P450 Enzyme,CYP450 Family,CYP450 Superfamily,Cytochrome P-450 Enzymes,Cytochrome P-450 Families,Cytochrome P-450 Monooxygenase,Cytochrome P-450 Oxygenase,Cytochrome P-450 Superfamily,Cytochrome P450,Cytochrome P450 Superfamily,Cytochrome p450 Families,P-450 Enzymes,P450 Enzymes,Cytochrome P 450,Cytochrome P 450 Dependent Monooxygenase,Cytochrome P 450 Enzyme,Cytochrome P 450 Enzyme System,Cytochrome P 450 Enzymes,Cytochrome P 450 Families,Cytochrome P 450 Monooxygenase,Cytochrome P 450 Oxygenase,Cytochrome P 450 Superfamily,Enzyme, Cytochrome P-450,Enzyme, P-450,Enzyme, P450,Enzymes, Cytochrome P-450,Enzymes, P-450,Enzymes, P450,Monooxygenase, Cytochrome P-450,Monooxygenase, Cytochrome P-450-Dependent,P 450 Enzyme,P 450 Enzymes,P-450 Enzyme, Cytochrome,P-450 Enzymes, Cytochrome,Superfamily, CYP450,Superfamily, Cytochrome P-450,Superfamily, Cytochrome P450
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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
D000906	Antibodies	Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D058886	Sterol 14-Demethylase	An NADPH-dependent P450 enzyme that plays an essential role in the sterol biosynthetic pathway by catalyzing the demethylation of 14-methyl sterols such as lanosterol. The enzyme acts via the repeated hydroxylation of the 14-methyl group, resulting in its stepwise conversion into an alcohol, an aldehyde and then a carboxylate, which is removed as formic acid. Sterol 14-demethylase is an unusual cytochrome P450 enzyme in that it is found in a broad variety of organisms including ANIMALS; PLANTS; FUNGI; and protozoa.	Sterol 14-Demethylases,CYP51 Cytochrome P-450,Cytochrome P-450 CYP51,Eburicol 14 alpha-Demethylase,Eburicol 14alpha-Demethylase,Lanosterol 14 alpha-Demethylase,Obtusifoliol 14alpha-Demethylase,Sterol 14-alpha-Demethylase,14 alpha-Demethylase, Eburicol,14 alpha-Demethylase, Lanosterol,14-Demethylase, Sterol,14-Demethylases, Sterol,14-alpha-Demethylase, Sterol,14alpha-Demethylase, Eburicol,14alpha-Demethylase, Obtusifoliol,CYP51 Cytochrome P 450,CYP51, Cytochrome P-450,Cytochrome P 450 CYP51,Cytochrome P-450, CYP51,Eburicol 14 alpha Demethylase,Eburicol 14alpha Demethylase,Lanosterol 14 alpha Demethylase,Obtusifoliol 14alpha Demethylase,P-450 CYP51, Cytochrome,P-450, CYP51 Cytochrome,Sterol 14 Demethylase,Sterol 14 Demethylases,Sterol 14 alpha Demethylase