Results 141 to 150 of about 5,963 (192)

Steroid 21-Hydroxylase Deficiency in Mice*

Endocrinology, 1988
The enzyme steroid 21-hydroxylase (21-OHase) plays a key role in adrenal steroidogenesis. Defects in this enzyme are responsible for one of the most common inborn errors of metabolism in humans. Duplicated genes for the enzyme are located in the class III region of the major histocompatibility complex (MHC), HLA.
H, Gotoh, T, Sagai, J, Hata, T, Shiroishi, K, Moriwaki   +4 more
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Enzyme-activated inhibitors of steroidal hydroxylases

The Journal of Steroid Biochemistry and Molecular Biology, 1995
Cytochrome P450 monooxygenases (CYP450) of the steroid biosynthetic pathways are highly substrate specific in comparison to the variable specificities of hepatic CYP450 enzymes. Both groups of enzymes catalyze the reductive cleavage of molecular oxygen with transfer of oxygen to the substrate to form hydroxylated derivatives.
J O, Johnston, C L, Wright, G W, Holbert
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Role of microsomal steroid hydroxylases in Δ7-steroid biosynthesis

Biochemistry (Moscow), 2013
CYP17 (steroid 17α-hydroxylase/17,20-lyase) is a key enzyme in steroid hormone biosynthesis. It catalyzes two independent reactions at the same active center and has a unique ability to differentiate Δ(4)-steroids and Δ(5)-steroids in the 17,20-lyase reaction.
T A, Sushko, A A, Gilep, A V, Yantsevich, S A, Usanov   +3 more
openaire   +2 more sources

Molecular Cloning of Steroid 21-Hydroxylase

Endocrine Research, 1984
Congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency is HLA-linked. The haplotype HLA-(A3);Bw47;DR7 is strongly associated with 21-OH deficiency and always carries a null allele at the complement C4A (Rodgers) locus. It seemed likely that this haplotype carries a deletion encompassing both the C4A and 21-OH loci. We hypothesized that
P C, White, B, Dupont, M I, New
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Disorders of Steroid 11β-Hydroxylase Isozymes*

Endocrine Reviews, 1994
The most active corticosteroids are 11 beta-hydroxylated. Humans have two isozymes with 11 beta-hydroxylase activity that are respectively required for cortisol and aldosterone synthesis. CYP11B1 (11 beta-hydroxylase) is expressed at high levels and is regulated by ACTH, whereas CYP11B2 (aldosterone synthase) is normally expressed at low levels and is ...
P C, White, K M, Curnow, L, Pascoe
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[29] Adrenal steroid hydroxylases

1969
Publisher Summary This chapter discusses the general procedures used in the laboratories for separating mitochondria and microsomes from the adrenal cortex of steers and for preparing a reaction medium for the hydroxylase assays. The chapter summarizes the most common steroid assays. Modifications of these procedures are pointed out on the individual
Otto Rosenthal, Shakunthala Narasimhulu
openaire   +1 more source

Disorders of steroid 11β-hydroxylase isozymes

Trends in Endocrinology & Metabolism, 1992
Steroid 11 beta-hydroxylase activity in the adrenal cortex is required for the synthesis of the major glucocorticoids and mineralocorticoids, but different isozymes mediate this conversion in the zona fasciculata, where cortisol is produced, and the zona glomerulosa, the site of aldosterone synthesis.
P C, White, L, Pascoe
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Steroid 21-Hydroxylase

1993
Cortisol synthesis in the zona fasciculata of the adrenal cortex requires five enzymatic steps: the cholesterol side chain is cleaved to yield pregnenolone, which is dehydrogenated at the 3β position to progesterone, which is successively hydroxylated at the 17α, 21 and 11β positions. The side-chain cleavage and the three hydroxylations are mediated by
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Steroid 11β-hydroxylase deficiency and related disorders

Endocrinology and Metabolism Clinics of North America, 2001
Three disorders result from mutations involving two closely linked 11 beta-hydroxylase genes. Steroid 11 beta-hydroxylase deficiency results from mutations in CYP11B1. This is a form of congenital adrenal hyperplasia (CAH) characterized by hypertension and signs of androgen excess. Mutations in CYP11B2 cause aldosterone synthase deficiency, an isolated
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Bovine steroid 21-hydroxylase: regulation of biosynthesis

Biochemistry, 1986
A recombinant cDNA clone, PBC21-1, specific for bovine steroid 21-hydroxylase cytochrome P-450 (P-450C21) was identified in a bovine adrenocortical cDNA library, and this identity was confirmed by nucleotide sequencing which revealed significant amino acid homology (77%) with human P-450C21 cDNA.
M E, John, T, Okamura, A, Dee, B, Adler, M C, John, P C, White, E R, Simpson, M R, Waterman   +7 more
openaire   +2 more sources