Hydroxysteroid Dehydrogenases
17-Hydroxysteroid Dehydrogenases
20-Hydroxysteroid Dehydrogenases
3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
A 3-hydroxysteroid dehydrogenase which catalyzes the reversible reduction of the active androgen, DIHYDROTESTOSTERONE to 5 ALPHA-ANDROSTANE-3 ALPHA,17 BETA-DIOL. It also has activity towards other 3-alpha-hydroxysteroids and on 9-, 11- and 15- hydroxyprostaglandins. The enzyme is B-specific in reference to the orientation of reduced NAD or NADPH.
11-beta-Hydroxysteroid Dehydrogenase Type 2
An high-affinity, NAD-dependent 11-beta-hydroxysteroid dehydrogenase that acts unidirectionally to catalyze the dehydrogenation of CORTISOL to CORTISONE. It is found predominantly in mineralocorticoid target tissues such as the KIDNEY; COLON; SWEAT GLANDS; and the PLACENTA. Absence of the enzyme leads to a fatal form of childhood hypertension termed, APPARENT MINERALOCORTICOID EXCESS SYNDROME.
11-beta-Hydroxysteroid Dehydrogenase Type 1
11-beta-Hydroxysteroid Dehydrogenases
Paraganglioma, Extra-Adrenal
A relatively rare, usually benign neoplasm originating in the chemoreceptor tissue of the CAROTID BODY; GLOMUS JUGULARE; GLOMUS TYMPANICUM; AORTIC BODIES; and the female genital tract. It consists histologically of rounded or ovoid hyperchromatic cells that tend to be grouped in an alveolus-like pattern within a scant to moderate amount of fibrous stroma and a few large thin-walled vascular channels. (From Stedman, 27th ed)
L-Lactate Dehydrogenase
Lactate Dehydrogenases
Estradiol Dehydrogenases
Succinate Dehydrogenase
Sulfotransferases
Paraganglioma
A neural crest tumor usually derived from the chromoreceptor tissue of a paraganglion, such as the carotid body, or medulla of the adrenal gland (usually called a chromaffinoma or pheochromocytoma). It is more common in women than in men. (Stedman, 25th ed; from Segen, Dictionary of Modern Medicine, 1992)
Cortisone
A naturally occurring glucocorticoid. It has been used in replacement therapy for adrenal insufficiency and as an anti-inflammatory agent. Cortisone itself is inactive. It is converted in the liver to the active metabolite HYDROCORTISONE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p726)
Steroid 17-alpha-Hydroxylase
A microsomal cytochrome P450 enzyme that catalyzes the 17-alpha-hydroxylation of progesterone or pregnenolone and subsequent cleavage of the residual two carbons at C17 in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP17 gene, generates precursors for glucocorticoid, androgen, and estrogen synthesis. Defects in CYP17 gene cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL) and abnormal sexual differentiation.
Alcohol Oxidoreductases
A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).
Steroids
A group of polycyclic compounds closely related biochemically to TERPENES. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (STEROLS), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. (From Hawley's Condensed Chemical Dictionary, 11th ed)
NAD
A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)
Isoenzymes
Hydrocortisone
Testosterone
A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.
Liver
Androsterone
A metabolite of TESTOSTERONE or ANDROSTENEDIONE with a 3-alpha-hydroxyl group and without the double bond. The 3-beta hydroxyl isomer is epiandrosterone.
Alcohol Dehydrogenase
A zinc-containing enzyme which oxidizes primary and secondary alcohols or hemiacetals in the presence of NAD. In alcoholic fermentation, it catalyzes the final step of reducing an aldehyde to an alcohol in the presence of NADH and hydrogen.
Glyceraldehyde-3-Phosphate Dehydrogenases
20-alpha-Hydroxysteroid Dehydrogenase
Aldehyde Dehydrogenase
Glutamate Dehydrogenase
Glucosephosphate Dehydrogenase
Glucose-6-Phosphate Dehydrogenase (G6PD) is an enzyme that plays a critical role in the pentose phosphate pathway, catalyzing the oxidation of glucose-6-phosphate to 6-phosphoglucono-δ-lactone while reducing nicotinamide adenine dinucleotide phosphate (NADP+) to nicotinamide adenine dinucleotide phosphate hydrogen (NADPH), thereby protecting cells from oxidative damage and maintaining redox balance.
Malate Dehydrogenase
Isocitrate Dehydrogenase
An enzyme of the oxidoreductase class that catalyzes the conversion of isocitrate and NAD+ to yield 2-ketoglutarate, carbon dioxide, and NADH. It occurs in cell mitochondria. The enzyme requires Mg2+, Mn2+; it is activated by ADP, citrate, and Ca2+, and inhibited by NADH, NADPH, and ATP. The reaction is the key rate-limiting step of the citric acid (tricarboxylic) cycle. (From Dorland, 27th ed) (The NADP+ enzyme is EC 1.1.1.42.) EC 1.1.1.41.
Phosphoadenosine Phosphosulfate
3'-Phosphoadenosine-5'-phosphosulfate. Key intermediate in the formation by living cells of sulfate esters of phenols, alcohols, steroids, sulfated polysaccharides, and simple esters, such as choline sulfate. It is formed from sulfate ion and ATP in a two-step process. This compound also is an important step in the process of sulfur fixation in plants and microorganisms.
Arylsulfotransferase
A sulfotransferase that catalyzes the sulfation of a phenol in the presence of 3'-phosphoadenylylsulfate as sulfate donor to yield an aryl sulfate and adenosine 3',5'-bisphosphate. A number of aromatic compounds can act as acceptors; however, organic hydroxylamines are not substrates. Sulfate conjugation by this enzyme is a major pathway for the biotransformation of phenolic and catechol drugs as well as neurotransmitters. EC 2.8.2.1.
Ketosteroids
NADP
Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)
Dihydrolipoamide Dehydrogenase
Carbohydrate Dehydrogenases
L-Iditol 2-Dehydrogenase
An alcohol oxidoreductase which catalyzes the oxidation of L-iditol to L-sorbose in the presence of NAD. It also acts on D-glucitol to form D-fructose. It also acts on other closely related sugar alcohols to form the corresponding sugar. EC 1.1.1.14
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Dehydroepiandrosterone
A major C19 steroid produced by the ADRENAL CORTEX. It is also produced in small quantities in the TESTIS and the OVARY. Dehydroepiandrosterone (DHEA) can be converted to TESTOSTERONE; ANDROSTENEDIONE; ESTRADIOL; and ESTRONE. Most of DHEA is sulfated (DEHYDROEPIANDROSTERONE SULFATE) before secretion.
Glycerolphosphate Dehydrogenase
Substrate Specificity
Glucose 1-Dehydrogenase
Amino Acid Sequence
Base Sequence
Ketoglutarate Dehydrogenase Complex
The Ketoglutarate Dehydrogenase Complex is a multi-enzyme complex involved in the citric acid cycle, catalyzing the oxidative decarboxylation of alpha-ketoglutarate to succinyl-CoA and CO2, thereby connecting the catabolism of amino acids, carbohydrates, and fats to the generation of energy in the form of ATP.
Stereoisomerism
Gene Expression Regulation, Enzymologic
Glucose Dehydrogenases
Phosphogluconate Dehydrogenase
Sugar Alcohol Dehydrogenases
NADH Dehydrogenase
A flavoprotein and iron sulfur-containing oxidoreductase that catalyzes the oxidation of NADH to NAD. In eukaryotes the enzyme can be found as a component of mitochondrial electron transport complex I. Under experimental conditions the enzyme can use CYTOCHROME C GROUP as the reducing cofactor. The enzyme was formerly listed as EC 1.6.2.1.
IMP Dehydrogenase
An enzyme that catalyzes the dehydrogenation of inosine 5'-phosphate to xanthosine 5'-phosphate in the presence of NAD. EC 1.1.1.205.
Acyl-CoA Dehydrogenase
Formate Dehydrogenases
Flavoproteins that catalyze reversibly the reduction of carbon dioxide to formate. Many compounds can act as acceptors, but the only physiologically active acceptor is NAD. The enzymes are active in the fermentation of sugars and other compounds to carbon dioxide and are the key enzymes in obtaining energy when bacteria are grown on formate as the main carbon source. They have been purified from bovine blood. EC 1.2.1.2.
Xanthine Dehydrogenase
alpha 1-Antitrypsin
3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)
A ketone oxidoreductase that catalyzes the overall conversion of alpha-keto acids to ACYL-CoA and CO2. The enzyme requires THIAMINE DIPHOSPHATE as a cofactor. Defects in genes that code for subunits of the enzyme are a cause of MAPLE SYRUP URINE DISEASE. The enzyme was formerly classified as EC 1.2.4.3.
Hydroxybutyrate Dehydrogenase
3-Hydroxyacyl CoA Dehydrogenases
Enzymes that reversibly catalyze the oxidation of a 3-hydroxyacyl CoA to 3-ketoacyl CoA in the presence of NAD. They are key enzymes in the oxidation of fatty acids and in mitochondrial fatty acid synthesis.
Pyruvate Dehydrogenase (Lipoamide)
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)
RNA, Messenger
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Catalysis
Dihydrouracil Dehydrogenase (NADP)
Uridine Diphosphate Glucose Dehydrogenase
Cytosol
Glucosephosphate Dehydrogenase Deficiency
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).
Receptors, Adrenergic, alpha
One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.