Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.8.1.4 (diaphorase)
2,754 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

F344 Male rats weighting between 90 and 110 gm were given 90 ppm diethylnitrosamine in their drinking water for 5 weeks. Seven weeks after the administration of carcinogen was completed, the rats were sacrificed and sections of their livers were embedded in methacrylate. Serial sections 2 or 4 micron in thickness demonstrated the presence of gamma-glutamyl transpeptidase, acid phosphatase, adenosine triphosphatase, aldehyde dehydrogenase, alkaline phosphatase, alpha-naphthyl butyrate esterase, DT diaphorase, glucose-6-phosphate dehydrogenase, and 5'-nucleotidase activity and glycogen. The use of 4-micron sections of methacrylate-embedded tissue allows the evaluation of many more phenotypic markers in serial sections than is currently possible with frozen sections.
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PMID:Examination of enzyme-altered foci with gamma-glutamyl transpeptidase, aldehyde dehydrogenase, glucose-6-phosphate dehydrogenase, and other markers in methacrylate-embedded liver. 287 68

This semi-automated colorimetric assay for the MB isoenzyme of creatine kinase (EC 2.7.3.2) is based on a monoclonal antibody ("Conan-MB") specific for this isoenzyme and is a modification of a previously published method (Vaidya et al., Clin Chem 1986;32:657-63). A 0.64-cm bead coated with 2 to 3 micrograms of antibody is incubated with 100 microL of serum and 10 microL of 0.2 mol/L beta-mercaptoethanol for 1 h at room temperature, to extract CK-MB. The beads are washed with de-ionized water and incubated with CK substrate for 45 min at 37 degrees C. A solution containing trans-1,2-diaminocyclohexane-N,N,N', N'-tetraacetic acid, p-iodonitrotetrazolium violet, and diaphorase is added and the resulting colored product is measured at 492 nm. The standard curve is linear to 200 U of CK-MB per liter, and analytical recovery is 97-113%. Total assay CV for low (9.7 U/L) and high (50.7 U/L) quality-control materials was 14.1% (n = 1878) and 11.6% (n = 1842), respectively. CK-MB activity correlated well (r = 0.978, n = 226) with CK-MB measured by a two-site mass immunoassay, and 99.4% of samples with CK-MB greater than or equal to 12 U/L (n = 347) were verified by electrophoresis on agarose.
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PMID:Semi-automated direct colorimetric measurement of creatine kinase isoenzyme MB activity after extraction from serum by use of a CK-MB-specific monoclonal antibody. 334 10

Investigations were carried out into the activity and localization of NADH-dependant diaphorase in boar spermatozoa. Semen samples were collected from healthy boars, used in A.I. centers. The enzyme was extracted with distilled water and Triton X-100. Two forms of diaphorase were found-water-soluble and Triton X-100 soluble, showing low activity-0.36 U/ml and 0.26 U/ml. The enzyme was localized in the mitochondria, manifesting different intensities of reaction between sperm cells in the same ejaculate. It was found, that a part of the mitochondria and outer doublets showed positive reaction. It is suggested that the enzyme regulates the ratio between reduced and oxidized forms of NADH, takes part in the energy balance and possibly in the mechanism of sperm motility.
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PMID:Activity and localization of NADH-dependant oxidoreductase (diaphorase) in boar spermatozoa. 366 51

Samples of bovine muscle (post rigor) were frozen at different temperatures between -5 degrees and -196 degrees C at different freezing rates, and thawed at room temperature. The activities of the mitochondrial enzymes lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase were determined in the supernatant of the tissue homogenates in phosphate buffer (total enzyme activity), as well as in the press juice of the intact tissue (enzyme activity in the sarcoplasma). Neither the temperature nor the rate of freezing (varying from 25.5 to 0.01 min/degrees C) showed a significant influence on the total enzyme activities. Freezing at -5 degrees and -10 degrees C (at different rates but without intracellular freezing) and thawing did not result in an appreciable release of enzymes. Below -10 degrees C the release of the three enzymes from their binding to the inner membrane of the mitochondrion into the sarcoplasmic fluid increased upon rapid freezing with decreasing temperature i.e. with increasing intracellular ice formation, whereas at slow freezing (with extracellular ice formation only) freezing below -20 degrees C did not cause further enzyme release. At freezing temperatures below -20 degrees C rapid freezing resulted in a significantly stronger release of the three enzymes than slow freezing. From these results it was concluded that the damage to mitochondrial membranes upon fast freezing is primarily a result of intracellular (and perhaps also intramitochondrial) ice formation, whereas the membrane damage during slow freezing is primarily due to dehydration caused by the migration of water from the muscle fibers into the extracellular space as a result of osmotic effects. Ion concentration in the nonfreezing fraction of tissue water seems to be only of minor importance for the disintegration of mitochondrial membranes.
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PMID:[Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle. VIII. The influence of temperature and rate of freezing of bovine muscle on the activity and subcellular distribution of the enzymes in the thawed tissue]. 384 Mar 12

Lipoamide dehydrogenase reacts irreversibly with arsonous acids, RAs(OH)2, and arsonic acids, RAs(O)(OH)2, to form enzyme-inhibitor complexes. The formation of inactive enzyme requires NADH and is kinetically first order in the presence of excess arsonous acid. The second-order rate constant for formation of the enzyme-inhibitor complex was 545 min-1 M-1 for phenylarsonous acid, C6H5As(OH)2, and 5640 min-1 M-1 for methanearsonous acid, CH3As(OH)2. The kinetics of formation of inactive enzyme in the presence of arsonic acids was found to obey a rate law predicted by a two-step mechanism in which a rate-limiting reduction of an arsonic acid to the corresponding arsonous acid by reduced enzyme, E(SH)2, preceded formation of an inactive binary complex of reduced enzyme and arsonous acid: ES2 + NADH + H+ = E(SH)2 + NAD+; E(SH)2 + RAs(O)(OH)2 = ES2 + RAs(OH)2 + H2O; and E(SH)2 + RAs(OH)2 = ES2AsR + 2H2O. GSSG reductase reacts reversibly with C6H5As(OH)2 to form an inactive binary addition compound in the presence of NADPH. The value of the association constant for formation of enzyme inhibitor complex at pH 7.0 was 119 M-1. The initial rate of the GSSG reductase-catalyzed oxidation of NADPH by GSSG was insensitive to MeAs(OH)2. The kinetics of inhibition of GSSG reductase by arsenite and C6H5As(O)(OH)2 were found to obey the rate law described for lipoamide dehydrogenase and arsonic acids. GSSG reductase catalyzed the oxidation of NADPH by p-arsanilic acid. The initial rate of oxidation of NADPH was linearly dependent on enzyme concentration. The turnover number for GSSG reductase with p-arsanilic acid as an oxidant was 0.13 mol NADPH mol FAD-1 min-1.
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PMID:Reactions of lipoamide dehydrogenase and glutathione reductase with arsonic acids and arsonous acids. 384 Mar 44

Samples of bovine muscle (post rigor) were frozen at -30 degrees C at two different rates (1.27 min/degrees C and 13.10 min/degrees C) and thawed at different rates between 1.6 (22 degrees C) and 430 min/degrees C (0 degrees C). The activities of the mitochondrial enzymes lipoamide dehydrogenase, citrate synthase, and beta-hydroxyacyl-CoA-dehydrogenase were determined in the supernatant of the tissue homogenate in phosphate buffer (total activity) and in the press juice of the intact tissue (activity in the sarcoplasma). The rate of thawing did not show a significant influence on total enzyme activities. In most cases, however, slow thawing caused a greater release of the enzymes from the mitochondria into the sarcoplasmic fluid than fast thawing, this effect being apparently independent of the rate of freezing. The greater damage to mitochondrial membranes upon slow thawing cannot be due to a longer exposure of the muscle cell to increased ionic strength in the non-freezable part of the cell water at the "critical" temperature around -3 degrees C because freezing of muscle samples at -3 degrees C and incubating them at -3 degrees C for five days resulted neither in changes of the total enzyme activities nor in a release of the three mitochondrial enzymes. From these results it is concluded that the influence of thawing rate on the damage to muscle mitochondria is probably not due to ionic effects or to recrystallization phenomena in the ice phase.
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PMID:[Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase in skeletal muscle. IX. The influence of the rate of thawing on activity and subcellular distribution in fast and slow frozen bovine muscle]. 384 Sep 38

Rats were coexposed to lead (Pb) and Copper (Cu) through drinking water and intraperitoneally, respectively, for a period of 21 days. Neurochemical studies in these rats showed significant reduction in the activity of adenosine triphosphatase, cytochrome-c-oxidase, diaphorase and in the levels of biogenic amines in the rats simultaneously exposed to the two metals compared to either of the metal alone. These neurotoxic effects were not related to the contents of either of the metals in the brain since their accumulation after combined exposure was much less than observed after individual exposure to Pb or Cu.
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PMID:Neurochemical changes in rats coexposed to lead and copper. 628 90

The compartimentation and the relative strength of binding of the enzymes lipoamide dehydrogenase (LIPDH), citrate synthase (CS), and beta-hydroxyacyl-coenzyme A-dehydrogenase (HADH) in mitochondria isolated from bovine muscle (M. sternomandibularis) were studied using the following methods: Availability of the enzymes for proteases before and after opening of the intracrystal line space and after disintegration of the mitochondrial membranes; release of the enzymes after different treatments of the mitochondria: homogenization with phosphate buffer plus Triton X-100; suspension in dest. water and saccharose-tris buffer with and without added digitonin; ultrasonic treatment; freezing and thawing. From the results it can be concluded that the three enzymes are bound to the inner surface of the inner membrane of the mitochondrion, and that the binding strength increases according to the series CS less than HADH less than LIPDH.
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PMID:[Lipoamide dehydrogenase, citrate synthase and beta-hydroxyacyl-CoA-dehydrogenase of skeletal muscle. II. Compartmentalization of the enzymes in muscle mitochondria and their relative binding capacity]. 638 Jan 31

The water-soluble carbodiimide, N-ethyl-3-(3-dimethylaminopropyl)carbodiimide was found to effectively cross-link ferredoxin to ferredoxin-NADP+ reductase. The covalent complex has a stoichiometry of 1 mol of ferredoxin per mol of the reductase. The flavoprotein moiety of the cross-linked complex maintains most of its diaphorase activity and more interestingly has gained the capacity to catalyze the NADPH-cytochrome c reaction without addition of free ferredoxin in the assay mixture. Furthermore, the cross-linked complex binds NADP+ with a Kd = 88 microM at an ionic strength of 0.02 M. These results show that a ternary complex among the reductase and its substrates can be formed, suggesting that the binding sites for ferredoxin and the pyridine nucleotides are distinct. The bound ferredoxin can interact with cytochrome c; the iron-sulfur cluster of the cross-linked complex is shown to be reduced under anaerobic conditions by NADPH and to be required for the catalysis of the NADPH-cytochrome c reductase reaction. The cross-linked complex, added to thylakoids inhibited by the antibody against the reductase, catalyzes the H2O-cytochrome c photoreduction, which suggests that the ferredoxin moiety of the complex can interact with its electron donor in the photosynthetic chain. Restoration of NADP+ photoreduction requires the addition of free ferredoxin.
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PMID:A cross-linked complex between ferredoxin and ferredoxin-NADP+ reductase. 672 48

We investigated the involvement of nitric oxide in trinitrobenzene-sulfonic acid (TNB) colitis. Every 24 h after TNB, rats were orally dosed with NG-nitro-L-arginine methyl ester (L-NAME; 30 mg/kg), NG-nitro-D-arginine methyl ester (D-NAME), or water, and food intake, body weight, and plasma nitrite levels were measured. On day 6, colonic nitric oxide synthase and myeloperoxidase (MPO) activity, histology, intestinal muscle growth, NADPH-diaphorase, and myenteric nerve function were assessed. Food intake and body weight were reduced during the first 72 h of colitis. On day 6 post-TNB, a fourfold increase in mucosal nitric oxide synthase, a 30-fold increase in MPO, and a fivefold elevation in plasma nitrite were measured. Smooth muscle hyperplasia and hypertrophy in both colonic muscle layers, numerous diaphorase-positive macrophages in the myenteric plexus, and a suppression of myenteric nerve function were also observed. Unlike D-NAME, oral L-NAME reduced MPO and intestinal muscle hyperplasia by > 90%. Likewise, plasma nitrite and colonic nitric oxide synthase were reduced by > 70%. L-NAME completely prevented macrophage infiltration into the muscle. Conversely, it had no effect on anorexia or intestinal smooth muscle hypertrophy, nor did it affect suppressed myenteric nerve neurotransmitter release. These results demonstrate the selective transmural protective effects of L-NAME in the inflamed colon, implicating nitric oxide as a mediator.
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PMID:The selective beneficial effects of nitric oxide inhibition in experimental colitis. 753 57


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