Biomaterial Database

Purification to homogeneity of aromatase from human placenta. 1986

S Nakajin, and M Shinoda, and P F Hall

Aromatase cytochrome P-450 has been purified from human placenta to homogeneity, as demonstrated by electrophoresis on polyacrylamide gels with SDS, and by double diffusion against an antibody raised in rabbits. The enzyme converts androstenedione to estrone (Vmax 13.3 n moles/min/n mole P-450; Km 30 microM) and testosterone to estradiol. Aromatase activity requires P-450, P-450 reductase and NADPH. Enzyme activity is inhibited by anti-aromatase antibodies and by 4-hydroxyandrostenedione. The enzyme shows a molecular weight of 55,000, is extremely unstable and spontaneously forms P-420 with a half-life of 2.5 days.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008861	Microsomes	Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	Microsome
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010920	Placenta	A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).	Placentoma, Normal,Placentome,Placentas,Placentomes
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001141	Aromatase	An enzyme that catalyzes the desaturation (aromatization) of the ring A of C19 androgens and converts them to C18 estrogens. In this process, the 19-methyl is removed. This enzyme is membrane-bound, located in the endoplasmic reticulum of estrogen-producing cells of ovaries, placenta, testes, adipose, and brain tissues. Aromatase is encoded by the CYP19 gene, and functions in complex with NADPH-FERRIHEMOPROTEIN REDUCTASE in the cytochrome P-450 system.	CYP19,Cytochrome P-450 CYP19,Cytochrome P-450(AROM),Androstenedione Aromatase,CYP 19,CYP19 Protein,Cytochrome P450 19,Estrogen Synthase,Estrogen Synthetase,P450AROM,Aromatase, Androstenedione,Cytochrome P 450 CYP19,Protein, CYP19