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)

The interaction of hydrophobic probes, 8-anilinonaphthalene-1-sulfonate (ANS) and 4-benzoylamido-4'-aminostilbene-2, 2'-disulfonate (MBAS), with pig heart lipoamide dehydrogenase [NADH: lipoamide oxidoreductase, EC 1.6.4.3] was investigated. When ANS or MBAS was mixed with the apoenzyme of lipoamide dehydrogenase, the fluorescence quantum yield, of each dye was enhancedd markedly and the emission maxima concurrently shifted to the blue. The quantum yield, 0.038, of ANS bound to the apoenzyme, calculated from the corrected emission spectrum, was eight times higher than that in buffer solution, and the value, 0.0090, for bound MBAS was eighteen times higher than that in buffer solution. Moreover, the absortion bands of both ANS and MBAS shifted to the red upon binding with the apoenzyme. A general feature of the absorption spectra of these dyes observed on changing the solvent from polar to apolar was a red shift of the absorption bands. These results indicate that ANS or MBAS bound to the apoenzyme of lipoamide dehydrogenase is situated in a hydrophobic region of the apoenzyme molecule. It was found that 2 moles of each dye was bound per mole of the apoenzyme, which contains two polypeptide chains. The dissociation constants for the ANS- and MBAS-apoenzyme complexes were estimated to be 1.03X10(-5) and 1.54X10(-5) M, respectively. The enhanced fluorescence of both dyes bound to the apoenzyme decreased linearly upon adding FAD and disappeared at about 2 moles of FAD per mole of the apoenzyme. This suggests that both ANS and MBAS were displaced from their binding sites on the apoenzyme by FAD. The protein fluorescence spectrum of the apoenzyme had a maximum at 352 nm, which was blue-shifted by 6 nm from that of tryptophan in the buffer. Upon binding ANS or MBAS, the maximum of the protein fluorescence of the apoenzyme returned to 350 nm for the holoenzyme, and the fluorescence intensity decreased. Thus, the conformation around some tryptophan residues was affected by the binding of the dyes. When guanidine hydrochloride (GuHCl) was added to the ANS-apoenzyme complex solution, the enhanced fluorescence due to the bound ANS decreased and the emission maximum concurrently shifted to the red. Further, the maximum of the protein fluorescence of the apoenzyme shifted to the red, indicating the exposure of some tryptophan residues buried in an apolar region of the apoenzyme. Thus the binding of ANS to the apoenzyme was inhibited by protein denaturation due to GuHCL. In contrast, the holoenzyme of lipoamide dehydrogenase did not bind ANS or MBAS at all.
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PMID:Interaction of hydrophobic probes with the apoenzyme of pig heart lipoamide dehydrogenase. 95 45

The levels of acetylcholine and choline were measured in various brain regions of the rat after fixation by microwave irradiation of the head and after decapitation and subsequent freezing in liquid nitrogen. Levels of acetylcholine were increased by approximately 50% after microwave irradiation, while choline levels were reduced. These biochemical findings were correlated with virtually complex loss of acetylcholinesterase and NADH-diaphorase activity after 1 s exposure to microwave irradiation at a level of 5 kW.
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PMID:Fast fixation of brain in situ by high intensity microwave irradiation: application to neurochemical studies. 104 75

1. Lipoyl dehydrogenase (NADH: lipoamide oxidoreductase, ED 1.6.4.3) and two asparagusate dehydrogenases from asparagus mitochondria were purified by a series of steps, freezing and thawing, sodium dodecylsulfate extraction, and chromatography on Sephadex G-200 and DEAE-cellulose. 2. Lipoyl dehydrogenase was highly specific for alpha-lipoic acid, which could not be replaced at all by asparagusic acid. Each of the asparagusate dehydrogenases was capable of reducing both asparagusic and alpha-lipoic acids by using NADH as hydrogen donor. 3. Reduction of alpha-lipoic cid with NADH by lipoyl dehydrogenase was activated by NAD, but that of asparagusic acid by asparagusate dehydrogenase was inactivated by NAD. 4. Lipoyl dehydrogenase and two asparagusate dehydrogenases differed in electrophoretic mobility on polyacrylamide gels.
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PMID:Asparagusate dehydrogenases and lipoyl dehydrogenase from asparagus mitochondria. 112 55

Infusion of 1 mul arachis oil containing 1.5 mug bis-(1 -methylethyl)phosphorofluoridate (di-isopropylfluorophosphate: DFP) into the caudate--putamen nucleus and substantia nigra of rats produced a considerable reduction of histochemical staining for acetylcholinesterase (AChE) in these two brain regions 30--120 min after injection. Thereafter, regeneration of AChE occurred within the zone of DFP effect. These new stores of AChE were associated with discrete neuronal perikarya and their processes. Intracerebral DFP administration had little or no histochemically detectable effect on NADH-diaphorase. Thionin staining was similarly unaffected. The results with punctate intracerebral application of DFP were replicated by intramuscular injection of 1.5 mg/kg DFP. Although the significance of dopaminergic--cholinergic interactions in the neostriatum could not be elucidated on the basis of these histochemical data, the thesis was advanced that dopamine neurons in the pars compacta of the substantia nigra also contained AChE, possibly to inactivate acetylcholine released from cholinergic fibers afferent to this neural structure.
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PMID:Acetylcholinesterase-containing neurons in the neostriatum and substantia nigra revealed after punctate intracerebral injection of di-isopropylfluorophosphate. 123 57

Triamcinoline acetonide (10 mg per kg of body weight a day) was administered to rabbit fed on a laboratory chow diet. The content of flavins in liver but not in kidney, muscle and brain started to decrease 24 h after a single dose. The activities of enzymes in the liver were determined: the activities of pyruvate dehydrogenase complex, lipoamide dehydrogenase (NADH:lipoamide oxidoreductase EC 1.6.4.3), NADH dehydrogenase (NADH : (acceptor) oxidoreductase EC 1.6.99.3) and D-amino acid oxidase (D-amino acid: oxygen oxidoreductase (deaminating) EC 1.4.3.3) were decreased but those of succinate dehydrogenase (succinate : (acceptor) oxidoreductase EC 1.3.99.1) and xanthine oxidase (xanthine : oxygen oxidoreductase EC 1.2.3.2) remained unchanged. The activities of enzymes in the kidney, however, remained unchanged except the decrease in the activity of pyruvate dehydrogenase complex.
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PMID:Effect of triamcinolone administration on content of flavins in rabbit liver. 127 76

The postnatal development of acetylcholinesterase (AChE, EC 3.1.1.7) and NADH-diaphorase was examined in the caudate-putamen nucleus and substantia nigra of rats ranging from 3 to 90 days in age. From 3 to 15 days post partum islands of AChE and NADH-diaphorase activity were observed in the caudate-putamen nucleus. Individual neuronal somata could also be seen in AChE-stained sections up to 15 days. At later ages neuropil staining became increasingly dense, and this presumably accounted for the infrequent visualization of cell bodies in the brains of older animals. During development AChE appeared in the caudate-putamen nucleus in a lateral to medial topographic order; analogously, enzyme staining in the neostriatum reappeared in the same lateral to medial topographic order in adult rats following irreversible AChE inhibition by intramuscularly injected bis-(1-methylethyl)phosphorofluoridate (di-isopropylfluorophosphate: DFP). Furthermore, DFP treatment in mature animals revealed the presence of AChE in striatal neurons having morphologies similar to those observed in newborn rats. A similar time-course of postnatal AChE development was observed in the substantia nigra. In both the pars compacta and pars reticulata individual cell bodies, which were visible at early ages (3-10 days), became increasingly obscured at later times after birth by extra-somata staining. Between the 6th and 15th postnatal days AChE-containing fibers were seen projecting apparently from pars compacta into pars reticulata. Comparison of the present results with histochemical data of other investigators on the postnatal development of monoamines indicated the likelihood of cholinergicmonoaminergic interactions in the neostriatum and substantia nigra.
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PMID:Postnatal development of acetylcholinesterase in the caudate-putamen nucleus and substantia nigra of rats. 127 70

Characteristics of DT diaphorase (NAD(P)H: (quinone acceptor) oxidoreductase, DTD) activity in Ictalurus punctatus and the effect of DTD activity on menadione (MND)-mediated reduction of acetylated cytochrome c (AcC) were examined. DTD activity in cytosols of four organs followed a distinct gradient in the order stomach greater than gill greater than liver greater than posterior kidney. A similar gradient was observed in organ-specific rates of in vitro AcC reduction in the presence of either NADH or NADPH as reducing equivalent. A greater proportion of the AcC reduction rate was sensitive to inhibition by dicoumarol (DC) in organs with relatively high DTD specific activity (e.g., stomach) than in organs with low DTD activity (e.g., kidney). No such trend was observed in the superoxide dismutase (SOD)-sensitive proportion of AcC reduction rates. DTD was observed to contribute to MND-mediated superoxide production to a greater extent in organs with high DTD activity than in organs with low DTD activity. DC-sensitive (i.e., DTD-mediated) AcC reduction was observed to increase with organ-specific DTD activity, and the majority of the AcC reduction rate was inhibitable by SOD. These findings demonstrate a direct contribution by DTD activity to MND-mediated superoxide production in this in vitro system. The role of I. punctatus DTD as a possible deleterious agent in quinone metabolism and implications regarding the traditional conception of DTD as a detoxifying enzyme are discussed.
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PMID:DT diaphorase [NAD(P)H: (quinone acceptor) oxidoreductase] facilitates redox cycling of menadione in channel catfish (Ictalurus punctatus) cytosol. 131 45

Endogenous cytochrome oxidase activity was investigated in the adult rat striatum at the light microscope level to see if it was distributed in accordance with the established striatal patch/matrix compartmentalisation. Striatal sections stained to visualise cytochrome oxidase activity were compared with serial sections stained to visualise tyrosine hydroxylase and calbindinD28k-like immunoreactivity, established markers of the matrix compartment. The distribution of endogenous cytochrome oxidase activity was found to coincide with the immunocytochemical staining pattern seen for tyrosine hydroxylase and calbindinD28k whereby areas of intense tyrosine hydroxylase and calbindinD28k-like immunoreactivity (termed the matrix) corresponded to areas of intense cytochrome oxidase activity. Conversely, areas of less intense tyrosine hydroxylase and calbindinD28k-like immunoreactivity (termed patches) corresponded to areas of low cytochrome oxidase activity. In addition, the distribution of two other oxidative enzymes involved in the regulation of mitochondrial respiration, succinic dehydrogenase and NADH-diaphorase, was examined in the striatum and substantia nigra by using histochemical techniques. Both NADH-diaphorase and succinic dehydrogenase histochemistry showed an uneven pattern of neuropil staining in the striatum. In the substantia nigra a few intensely stained cell bodies were seen in the dorsal-lateral tip of the pars reticulata with both histochemical techniques. By using an anti-cytochrome oxidase antibody an abundance of immunoreactive cell bodies and processes were seen in the substantia nigra, particularly in the dorso-medial rim and dorsal tip of the pars reticulata. The substantia nigra pars lateralis contained many intensely stained cytochrome oxidase-like immunoreactive cell bodies and processes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Compartmental distribution of cytochrome oxidase in the striatum of the rat. 134 42

A feasibility study aimed at stabilization of L-lactate-dehydrogenase, L-malate-dehydrogenase, alcohol-dehydrogenase and diaphorase by the recently described method of enzyme 'encagement' was conducted. This method involves derivatizing the enzymes with polyglutaraldehyde, followed by secondary crosslinking with amino derivatives of polyacrylamide. Encagement conditions were optimized for each of the four enzymes, so as to achieve the highest thermal stability combined with highest catalytic activity. Depending on the encagement conditions, residual activities were in the range of 18% to 96% with higher values in the presence of cofactors. Increases in thermal stabilization of up to 26-fold were obtained. For high retention of enzymic activity and stability, the most significant factor was the concentration of polyglutaraldehyde; the crosslinking polymers had only a negligible effect. Furthermore, the significant enhancement in thermal stability could be attained without perturbing the kinetic parameters: Km values for NADH and pH optima remained unaltered for the stabilized enzymes.
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PMID:Stabilization of NAD(+)-dependent dehydrogenases and diaphorase by bilayer encagement. 136 7

These studies concern the initial steps in 4-nitroquinoline 1-oxide (4NQO) metabolism in relation to mechanisms of anticarcinogenesis. Butylated hydroxyanisole (BHA) administration by a protocol known to inhibit the pulmonary tumorigenicity of 4NQO in A/HeJ mice enhanced hepatic and pulmonary activities for 4NQO metabolism by two major pathways, conjugative detoxification and nitroreductive activation. High-performance liquid chromatography analysis showed approximate doubling of two types of glutathione transferase subunits with 4NQO-conjugating activity in livers of BHA-treated mice. Similar increases were observed in hepatic 4NQO-conjugating activity and in Vmax, while Km for 4NQO was 39 to 43 microM. Pulmonary 4NQO-glutathione transferase activity increased 24 to 29%. DT diaphorase activity toward 4NQO was elevated 3.3-fold in livers and 2.7-fold in lungs of BHA-treated mice. However, the predominant 4NQO reductase of liver and lung was dicumarol resistant, had a strong preference for NADH, and showed little if any response to BHA. This Mr 200,000 enzyme, partially purified from livers of Swiss mice, exhibited the stoichiometry of 2-NADH/4NQO expected for reduction of 4NQO to 4-hydroxyaminoquinoline 1-oxide. Its high affinity for 4NQO (Km, 15 microM) signified a much greater influence on 4NQO metabolism than DT diaphorase (Km, 208 microM). The dicumarol-resistant 4NQO reductase differed from several known cytosolic nitroreductases. The results suggest that protection by BHA may result from alteration of the balance between 4NQO activation and conjugation.
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PMID:Nitroreductases and glutathione transferases that act on 4-nitroquinoline 1-oxide and their differential induction by butylated hydroxyanisole in mice. 137 76


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