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Results 401 - 450 of 811
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Butò S - - 1994
The study reports on the development of a bioreactor for the production of alpha-keto acids from D,L- or D-amino acids using Rhodotorula gracilis D-amino acid oxidase. D-amino acid oxidase was co-immobilized with catalase on Affi-Gel 10 matrix, and the reactor was operated as a continuous-stirred tank reactor (CSTR) or stirred ...
Chen K - - 1994
A trout liver monoamine oxidase (MAO) cDNA was cloned by screening a cDNA library with a human MAO-A cDNA probe. The trout MAO cDNA encodes 499 amino acids, with a molecular mass of 56.6 kDa. The deduced amino acid sequence of trout MAO shows 70% and 71% identity with those ...
Jayanthi S - - 1994
Glyoxylic lithiasis by acute intoxication with sodium glyoxylate, significantly raised the levels of renal tissue calcium and oxalate which has been reflected simultaneously in their urinary levels. Administration of DL alpha-lipoic acid lowered the oxalate levels in the kidney and urine. Sodium glyoxylate administration resulted in enhanced liver glycollate oxidase ...
O'Regan M H - - 1994
The efflux of hypoxanthine, xanthine and uric acid into cortical superfusates was studied with the cortical cup technique in the rat. Twenty minutes of four vessel occlusion followed by reperfusion results in a massive increase in the efflux of these purine metabolites. Amflutizole, 10 microM administered topically into the cortical ...
Gonvindaraj S - - 1994
Cytochrome P450BM-3 is a fatty acid hydroxylase that consists of a heme domain covalently attached to a diflavin (FMN+FAD) cytochrome P450 reductase domain. The heme and flavin domains can be separately expressed and purified from E. coli recombinant expression systems. Normally P450s require a protein redox partner as a source ...
Kamiyama T - - 1994
Novel thrombin inhibitors, bacithrocins A, B and C, have been isolated from the culture broth of Bacillus laterosporus Laubach NR 2988. The structures of these inhibitors have been determined to be N-acyl-L-phenylalanyl-DL-arginal by the 2D-NMR experiments on their oxidation products and by amino acid analysis. Bacithrocin A inhibits thrombin, factor ...
Gadda G - - 1994
D-amino acid oxidase from the yeast Rhodotorula gracilis is irreversibly inactivated by reaction with TNBS with complete inactivation accompanied by covalent modification of lysine residues of the protein. The inactivation was biphasic, the fast phase being dependent on TNBS concentration and completed in less than 1 minute. The competitive inhibitor ...
Shimamura A - - 1994
The glucosyltransferases (GTFs) of mutans streptococci are important virulence factors in the sucrose-dependent colonization of tooth surfaces by these organisms. To investigate the structure-function relationship of the GTFs, an approach was initiated to identify amino acid residues of the GTFs which affect the incorporation of glucose residues into the glucan ...
Rocha L - - 1994
A new gamma-pyrone (hyperbrasilone), three known xanthones (1,5-dihydroxyxanthone, 5-hydroxy-1-methoxyxanthone and 6-deoxyjacareubin) and betulinic acid have been isolated from a dichloromethane extract of stems and roots of Hypericum brasiliense. Their structures were established by spectroscopic methods (UV, EI-MS, 1H and 13C NMR) and that of the gamma-pyrone was confirmed by X-ray ...
Roy S K - - 1994
The role of rat liver cytosolic lipoxygenase in the metabolism of benzidine was studied using linoleic acid as a cosubstrate. Under optimum assay conditions, cytosolic dioxygenase activity in the presence of 3.5 mM linoleic acid at pH 7.2 was 74.07 +/- 1.43 nmoles/min/mg protein. Benzidine was oxidized at the rate ...
Nakayama N - - 1994
Fatty acid subterminal (omega-1 approximately omega-3) hydroxylase of the fungus Fusarium oxysporum was solubilized from the microsomal fraction and partially purified. The hydroxylase activity was recovered into a single active fraction, and its spectral nature showed the presence of cytochrome P-450 (P-450). Fatty acid hydroxylase activity was markedly restored upon ...
Endo Y - - 1994
Monoamine oxidase B (MAO-B) inhibitors were isolated from the bark of a Brazilian plant, Himatanthus sucuuba (SPR.). Assignments of the 1H- and 13C-NMR data using two dimensional (2D)-NMR techniques showed the active components to be known lichen depsides, confluentic acid (1) and 2'-O-methylperlatolic acid (2). The depside (1) showed selective ...
Seip J E - - 1994
A variety of methods for the immobilization of glycolate oxidase have been examined for the preparation of a catalyst for the oxidation of glycolic acid to glyoxylic acid. The co-immobilization of glycolate oxidase and catalase on oxirane acrylic beads produced a catalyst which was stable to the reaction conditions used ...
Zhang Z R - - 1994
The electrochemical properties of benzoquinone and ferrocene monocarboxylic acid, which can be used as mediators for enzymatic reactions were studied at a polyaniline coated platinum electrode. Benzoquinone and ferrocene monocarboxylic acid were used in the catalytic cycle of a glucose oxidase-glucose reaction.
Anyanwutaku I O - - 1994
The copper oxidases human ceruloplasmin and Polyporous anceps laccase catalyze the oxidative coupling of mithramycin (1) and its aglycone chromomycinone (2) with p-hydroquinone to form new mithramycin-hydroquinone (3) and chromomycinone-hydroquinone adducts (4), respectively. Similar adducts could be formed by the nonenzymatic mimic of this reaction using benzoquinone and these aureolic ...
Bazzett T J - - 1994
We recently reported the use of a chronic dialytic delivery system for intrastriatal administration of quinolinic acid in the rat. This system produces neurodegeneration with some characteristics similar to post mortem brain tissue from Huntington's disease patients, including reduced cytochrome oxidase staining, a decreased number of Nissl-stained neurons, and relative ...
Castillo M P - - 1994
This method was proposed earlier for measuring glucose in a peroxidase-glucose oxidase system but has not been studied for determination of manganese peroxidase (MnP) activity. The assay is based on the oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone (MBTH) and 3-(dimethylamino)benzoic acid (DMAB). The reaction of MBTH and DMAB in the presence ...
Denu J M - - 1994
D-Amino acid oxidase catalyzes the oxidation of D-amino acids to imino acids with subsequent transfer of the electrons to molecular oxygen. Proposed mechanisms for the mode of cleavage of the substrate CH bond include stepwise formation of a carbanion, followed by attack of the carbanion on the enzyme-bound FAD, direct ...
Warhurst A M - - 1994
Rhodococcus rhodochrous NCIMB 13259 grows on styrene, toluene, ethylbenzene, and benzene as sole carbon sources. Simultaneous induction tests with cells grown on styrene or toluene showed high rates of oxygen consumption with toluene cis-glycol and 3-methylcatechol, suggesting the involvement of a cis-glycol pathway. 3-Vinylcatechol accumulated when intact cells were incubated ...
Nanda A - - 1994
In phagocytes, superoxide generation by the NADPH oxidase is accompanied by metabolic acid production. Cytoplasmic acidification during this metabolic burst is prevented by a combination of H+ extrusion mechanisms, including a unique H+ conductance. NADPH oxidase is deficient in chronic granulomatous disease (CGD) patients. The burst of acid production is ...
Yamamoto T - - 1994
Two new Capnocytophaga species, for which we propose the names Capnocytophaga haemolytica and Capnocytophaga granulosa, were isolated from supragingival dental plaque of adults. The phenotypic characteristics of these organisms were the same as those of the genus Capnocytophaga: gram-negative rods; CO2 requirement; gliding motility; catalase negative; oxidase negative; acids produced ...
Juorio A V - - 1994
These studies were carried out to determine whether the greater abundance of monoamine oxidase B in the guinea pig affects the actions of (-)-deprenyl on dopamine metabolism in whole tissue or in extracellular fluid. The administration of (-)-deprenyl in doses that do not affect monoamine oxidase A activity (1-4 mg ...
Adkins R M - - 1994
We examined the nucleotide and amino acid sequence variation of the cytochrome c oxidase subunit II (COII) gene from 25 primates (4 hominoids, 8 Old World monkeys, 2 New World monkeys, 2 tarsiers, 7 lemuriforms, 2 lorisiforms). Marginal support was found for three phylogenetic conclusions: (1) sister-group relationship between tarsiers ...
Chang W S - - 1994
The stems of Bougainvillea spectabillis Wild (Nyctaginaceae) have been used in folk medicine against hepatitis. Spinasterol, 22, 23-dihydrospinasterol and caffeic acid were isolated from the plant stems and characterized. Caffeic acid has not been previously isolated from this plant but spinasterol has been isolated from the leaves. Caffeic acid was ...
Yu P H - - 1994
Aliphatic N-propargylamines have recently been discovered to be highly potent, selective, and irreversible monoamine oxidase B (MAO-B) inhibitors. N-Methyl-N-(2-pentyl)propargylamine (M-2-PP) and N-methyl-N-(2-hexyl) propargylamine (2-HxMP), for example, are approximately fivefold more potent that l-deprenyl at inhibiting mouse brain MAO-B activity following oral administration. These inhibitors are nonaromatic compounds and are chemically ...
Pinot F - - 1994
Incubation of the microsomal fraction from etiolated wheat shoots (Triticum aestivum L. cv Etoile de Choisy) with [1-14C]oleic acid led to the formation of three polar metabolites which were identified as 18-, 17- and 16-hydroxyoleic acids by gas chromatography/mass spectra analysis. They were generated in a molar ratio of 1.4/4.6/4, ...
Tsujita M - - 1994
Retinal oxidase (retinoic acid synthase) (EC 1.2.3.11) was purified electrophoretically, as a single protein band, from rabbit liver cytosol. The characteristic properties, enzymatic reaction mechanism, substrate specificity and kinetic parameters for retinals and molecular oxygen of the retinal oxidase were investigated. The Km values for all-trans-retinal of the retinal oxidase ...
Rui C S - - 1994
Leucine dehydrogenase/L-amino acid oxidase was proposed as an enzymatic conversion system for ammonia and its application to amperometric assay of creatinine was investigated. Ammonia formed by creatinine deiminase catalyzed hydrolysis of creatinine was converted to L-leucine by leucine dehydrogenase, and the oxidation of L-leucine by L-amino acid oxidase was detected ...
Herbert M A - - 1994
This report describes a patient with high serum phytanic acid concentration due to phytanic acid alpha-oxidase deficiency (classical Refsum disease). He presented unusually early, hypotonia and developmental delay being apparent by 7 months. A generalized peroxisomal disorder (so-called 'infantile Refsum disease') was excluded by analyses of pristanic acid, very long-chain ...
Carter D A - - 1994
Cyclization of aspartic acid and asparagine to succinimides is thought to be a common spontaneous aging reaction in proteins, but the instability of the succinimide ring has made it difficult to directly measure this structure. Chemical reduction has now been tested as a means of trapping succinimides as stable derivatives, ...
D'Aniello A - - 1993
D-Amino acids administered to animals are absorbed by the intestine and transported through the blood-stream to solid tissues where they are oxidized in vivo by D-amino acid oxidase and D-aspartate oxidase to produce the same compounds they do in vitro; i.e. NH3, H2O2, and the keto acid corresponding to the ...
Johansson E - - 1993
A biosensor for the analysis of D-amino acids is described. Carbon paste (graphite/paraffin oil) was chemically modified with immobilized D-amino acid oxidase and either horse-radish peroxidase or fungal peroxidase from Arthromyces ramosus. The two enzymes dissolved in buffer, together with an amine containing oligomer or polymer, were adsorbed on dry ...
Poquet I - - 1993
The analyses of hybrid proteins and of deletion and insertion mutations reveal that the only amino acid at the amino-proximal end of the cell surface lipoprotein pullulanase that is specifically required for its extracellular secretion is an aspartate at position +2, immediately after the fatty acylated amino-terminal cysteine. To see ...
Allegrezza-Giulietti A - - 1993
Reported here are the results of a study carried out in order to assess the possible influence of the major circulating active metabolite of nabumetone, 6-methoxy-2-naphthylacetic acid, on some aspects of polymorphonuclear leukocytes activation. The action of 6-methoxy-2-naphthylacetic acid was tested on the following features of polymorphonuclear leukocytes activation: reactive ...
Cancel A M - - 1993
Phanerochaete chrysosporium is a white rot fungus which secretes a family of lignin-degrading enzymes under nutrient limitation. In this work, we investigated the roles of veratryl alcohol and lignin in the ligninolytic system of P. chrysosporium BKM-F-1767 cultures grown under nitrogen-limited conditions. Cultures supplemented with 0.4 to 2 mM veratryl ...
Sawai T - - 1993
The superoxide-generating NADPH oxidase system in phagocytes consists of membrane-associated cytochrome b558 and three cytosolic components named p67-phox, p47-phox, and rac p21s. In a cell-free system consisting of membrane and cytosol, the oxidase can be activated with guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) and an unsaturated fatty acid such as arachidonic ...
Grune T - - 1993
The accumulation of the aldehydic lipid peroxidation product 4-hydroxynonenal and thiobarbituric acid-reactive substances was demonstrated during anoxia/reoxygenation of isolated rat hepatocytes. 4-Hydroxynonenal was detected as dinitrophenylhydrazone derivative by means of an isocratic HPLC separation. The highest 4-hydroxynonenal level was found 15 min after the beginning of reoxygenation. The concentration of ...
Frederiks W M - - 1993
D-Amino acid oxidase activity was demonstrated in peroxisomes of rat liver using unfixed cryostat sections and a histochemical technique using cerium ions as capture reagent for hydrogen peroxide and diaminobenzidine, cobalt ions and exogenous hydrogen peroxide to visualize the final reaction product for light microscopical analysis. Cytophotometric analysis of liver ...
Kvam C - - 1993
The scavenging effect of 2,6-diisopropylphenol on hydroxy radicals produced by xanthine oxidase was assessed by evaluating the in vitro depolymerisation of hyaluronan in artificial synovial fluid by size-exclusion chromatography. After 1 hour, the number-average molecular weight of hyaluronan remained unchanged (100%) with 2,6-diisopropylphenol, whereas it dropped to 90% with methylprednisolone ...
Pedersen J Z - - 1993
Protein-radical enzymes use a free radical located on an intrinsic amino acid residue as a cofactor. The amino acid involved can be a tyrosine (ribonucleotide reductase, photosystem II, prostaglandin H synthase), a modified tyrosine (amine oxidase, galactose oxidase), a tryptophan (cytochrome c peroxidase), a modified tryptophan (methylamine dehydrogenase) or a ...
Kienle I - - 1993
An enzymatic end-point assay of trehalose using acid trehalase from yeast is described. After quantitative hydrolysis of trehalose by acid trehalase, the resulting glucose is assayed with the commercially available glucose oxidase/peroxidase dye system. Pre-existing glucose is determined in a control reaction from which acid trehalase is omitted. When intact ...
Dyck L E - - 1993
The effects of the administration of selective and non-selective inhibitors of monoamine oxidase (MAO) on the concentrations of three trace acid metabolites [phenylacetic acid (PAA); m-hydroxyphenylacetic acid (mHPAA); and p-hydroxyphenylacetic acid (pHPAA)] and of an acid metabolite of dopamine [3,4-dihydroxyphenylacetic acid (DOPAC)] in the rat striatum were determined. Administration of ...
Male K B - - 1993
A flow injection analysis (FIA) biosensor system was developed for the determination of the artificial sweetener aspartame (L-aspartyl-L-phenylalanine methyl ester). The system consisted of an enzyme column of pronase immobilized on activated arylamine glass beads and a L-amino acid oxidase electrode connected in series. The dipeptide bond of aspartame was ...
Morais M da S Mda - - 1993
1. An organic solvent-extractable product was obtained from incubations of primaquine (70 mM) with H2O2 (70mM) and horseradish peroxidase (0.5 mg/ml) in acetate buffer, pH4.2. 2. The metabolite was characterized as 5,5-di-(8-[(4-amino-1-methylbutyl)amino]-6-methoxyquinoline) by 1H-n.m.r., mass, FT-i.r. and u.v.-visible spectroscopy. 3. Incubations of rat erythrocytes with 5,5-di-(8-[(4-amino-1-methylbutyl)amino]-6-methoxyquinoline) led to the formation ...
Male K B - - 1993
A flow injection analysis (FIA) biosensor system has been developed for the determination of glucose from urine, blood plasma and foodstuffs. Glucose oxidase was immobilized onto porous aminopropyl glass beads via glutaraldehyde activation to form an enzyme column. The hydrogen peroxide released from the conversion of glucose to gluconic acid ...
D'Aniello A - - 1993
This study reports the presence of high concentrations of free D-aspartic acid (D-Asp) in the circumoesophageal ganglia of the opisthobranch mollusc Aplysia fasciata. D-Asp was discovered using specific methods that employ Octopus D-aspartate oxidase and hog kidney D-amino acid oxidase to measure D-Asp levels. The concentration of D-Asp was 0.281 ...
Solinas S P - - 1993
The oxidation of L-aminoethylcysteine (AEC) by L-amino acid oxidase has been compared with that of the respective sulfoxide (AEC-SO) and sulfone (AEC-SO2). Spectral and HPLC analyses of the incubates reveal the formation of the respective cyclic ketimines. While the ketimine coming from AEC is subjected to autooxidation yielding the sulfoxide ...
Manno M - - 1992
1 Two cases of lethal poisoning following acute inhalation of extremely high concentrations of dichloromethane (DCM) are reported. The concentrations of the solvent found in the blood of the two subjects collected at autopsy and analysed by gas chromatography/mass spectrometry (572 and 601 mg l-1) were compatible with those measured ...
Saeki T - - 1992
The essential part of the ETB-selective agonist N-acetyl-GluAlaValTyrPheAlaHisLeuAspIleIleTrp (N-Ac-4AlaET-1(10-21)) for ETB agonism was studied by single amino acid replacement. Single L-alanine substitutions at positions 14, 17, 20 and 21 and the corresponding D-amino acid substitutions at positions 14 and 16-21 resulted in remarkable decreases in ETB binding activity. Furthermore, these ...
Cserháti T - - 1992
The interaction of 17 monoamine oxidase inhibitory drugs (propargylamine derivatives) with amino acids was studied by charge-transfer chromatography. The data set was evaluated by principal component analysis (PCA). To assess the effect of the information loss caused by normalization, PCA was separately carried out on the covariance and on the ...
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