Dehydrogenases prostaglandin

Coggins KG, Latour A, Nguyen MS et al (2002) Metabolism of PGE2 by prostaglandin dehydrogenase is essential for remodeling the ductus arteriosus. Nat Med 8 91-92... 

This enzyme [EC 1.1.1.50], also referred to as hydroxy-prostaglandin dehydrogenase, catalyzes the reaction of androsterone with NAD(P)+ to produce 5a-androstane-3,17-dione and NAD(P)H. Other 3a-hydroxysteroids can act as substrates as well as 9-, 11- and 15-hydroxy-prostaglandins. The stereochemistry is B-specific with respect to the pyridine coenzymes. 

A. 17,20 lyase is required for androgen synthesis, cyclooxygenase for prostaglandin production, 11- 3-hydroxysteroid dehydrogenase-2 acts as a reductase-converting cortisol to its inactive 11-keto derivative cortisone, whereas 18-hydroxylase is required for aldosterone production. 

A similar mechanism has been found for 17(3-hydroxysteroid dehydrogenase (17(3-HSD), the enzyme that regulates the concentrations of estradiol and testosterone in human [5,16,17] (Figure lb). Genetics diseases associated with mutations in this enzyme lead to developmental abnormalities [18]. Enzymes that regulate the concentrations of retinoids [19] and prostaglandins [20] may also have a similar role [6]. 

Baker ME. Genealogy of regulation of human sex and adrenal function, prostaglandin action, snapdragon and petunia flower colors, antibiotics, and nitrogen fixation functional diversity from two ancestral dehydrogenases. Steroids 56 1991 354-360. 

For foreign compounds, the majority of oxidation reactions are catalyzed by monooxygenase enzymes, which are part of the mixed function oxidase (MFO) system and are found in the SER (and also known as microsomal enzymes). Other enzymes involved in the oxidation of xenobiotics are found in other organelles such as the mitochondria and the cytosol. Thus, amine oxidases located in the mitochondria, xanthine oxidase, alcohol dehydrogenase in the cytosol, the prostaglandin synthetase system, and various other peroxidases may all be involved in the oxidation of foreign compounds. 

Oxidation Cytochrome P450s Prostaglandin synthetase Flavin-containing monooxygenases Alcohol and aldehyde dehydrogenases... 

Hydroxyhept-6-enoates have been key intermediates in the synthesis of a variety of natural products, especially of the arachidonic acid metabolic pathway, including prostaglandins, leukotrienes, and isoprostanes [105, 113-118]. The usage of two enantiocomplementary enzymes allowed convenient access to both enantiomers via an ADH-catalyzed reduction of 5-oxo-hept-6-enoate. Alcohol dehydrogenase from Lactobacillus brevis (ADH-LB) furnished the (S )-enantiomer, Thermoanaerobacter sp. ADH (ADH-T) the (7 )-enantiomer in excellent enantiomeric access respectively [119]. A cross-metathesis reaction followed by cyclopropanation led to the formal synthesis of constanolactones C and D (Fig. 16) [86, 120, 121]. 

Besides 12-LOX in platelets, the 5-LOX isoforms are constitutive in neutrophils. Evidences indicate that LOXs are involved in inflammation diseases and in atherosclerosis. 5-LOX is the enzyme that catalyzes the formation of leukotrienes with potential role for leukocytes and platelets interaction and inflammation. After platelet and leukocyte stimulation, products of both COX-1 and 5-LOX pathways increase. COX-1 activity derivatives increase the vascular permeability mediated by prostaglandins and produce platelet aggregation mediated by TXA2. The product of the lipoxygenase pathway, 5-oxo-6,8,1 1,14-eicosatetraenoic acid (5-Oxo-ETE), induces leukocyte chemotaxis and inflammation. 5-Oxo-ETE is formed by the oxidation of 5S-hydroxy-ETE (5-HETE) by 5-hydroxyeicosanoid dehydrogenase (5-HEDH), a microsomal enzyme found in leukocytes and platelets (42). 

PropUtrabacUrium arabinosum, -gly-cerophosphate dehydrogenase of, 260 2-Propyn-l-ol, catalase and, 404 Prostaglandin, biosynthesis, 168 Prosthetic groups, succinate dehydrogenase, 234-235... 

Phosphatidic acid phosphatase Post proline cleaving enzyme Prostaglandin dehydrogenase Succinate dehydrogenase Sulfotransferase... 

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