Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The kinetic constants for hydrolysis and transfer (with hydroxylamine as the alternate acceptor) of the aliphatic amidase (acylamide amidohydrolase, EC 3.5.1.4) from Pseudomonas aeruginosa were determined for a variety of acetyl and propionyl derivatives. The results obtained were consistent with a ping-pong or substitution mechanism. Product inhibition, which was pH dependent, implicated an acyl-enzyme compound as a compulsory intermediate and indicated that ammonia combined additionally with the free enzyme in a dead-end manner. The uncompetitive activation of acetamide hydrolysis by hydroxylamine and the observation that the partitioning of products between acetic acid and acetohydroxamate was linearly dependent on the hydroxylamine concentration substantiated these conclusions and indicated that deacylation was at least partially rate limiting. With propionamide as the acyl donor apparently anomalous results, which included inequalities in certain kinetic constants and a hyperbolic dependence of the partition ratio on the hydroxylamine concentration, could be explained by postulating a compulsory isomerisation of the acyl-enzyme intermediate prior to the transfer reaction.
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PMID:Kinetic mechanism of the aliphatic amidase from Pseudomonas aeruginosa. 11 Mar 50

Strains of Geotrichum candidum were isolated from the surface of a commercial sample of Limburger cheese and from raw milk. Growth of the isolates in an acidified tryptone-yeast extract medium was accompanied by a rise in the pH of the medium from 3.5 to above 7.0 Ammonia production, as indicated by Nesslerization, was associated with the deamination of glutamic and aspartic acids. The first reaction in the production of ammonia from glutamic acid, isomerization to beta-methylaspartic acid, required vitamin B12 and the second reaction, the deamination of beta-methylaspartic acid to mesaconic acid and ammonia, was dependent on magnesium and potassium. The conversion of aspartic acid to fumaric acid and ammonia required magnesium. These minerals were in sufficient amounts in the Limburger cheese for optimum deaminase activity.
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PMID:Deamination of glumatic and aspartic acids by Geotrichum candidum. 58 76

It is established that purified nuclear and mitochondrial fractions of the rat brain possess a noticeable AMP-deaminase activity. ATP is an effective activator of AMP-deaminase in the both fractions, but this enzyme is also stimulated by hexokinase in the mitochondrial fraction. The ammonia production from ADP in the mitochondrial fraction is connected with the formation on ATP and AMP under the influence of myokinase and subsequent deamination of AMP by AMP-deaminase.
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PMID:[AMP-deaminase activity of rat brain nuclear and mitochondrial fractions]. 72 89

A strain of Klebsiella pneumoniae that used aliphatic nitriles as the sole source of nitrogen was adapted to benzonitrile as the sole source of carbon and nitrogen. Gas chromatographic and mass spectral analyses of culture filtrates indicated that K. pneumoniae metabolized 8.4 mM benzonitrile to 4.0 mM benzoic acid and 2.7 mM ammonia. In addition, butyronitrile was metabolized to butyramide and ammonia. The isolate also degraded mixtures of benzonitrile and aliphatic nitriles. Cell extracts contained nitrile hydratase and amidase activities. The enzyme activities were higher with butyronitrile and butyramide than with benzonitrile and benzamide, and amidase activities were twofold higher than nitrile hydratase activities. K. pneumoniae appears promising for the bioremediation of sites contaminated with aliphatic and aromatic nitriles.
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PMID:Metabolism of benzonitrile and butyronitrile by Klebsiella pneumoniae. 153 79

Porphobilinogen-deaminase (PBG-D) and PBG-D-isomerase complex (PBG-D-I) from pig liver were isolated and partially purified. Uroporphyrinogen I and III formation was found to be linear with time and protein concentration. Optimal pH was about 7.4 and 7.6-7.8 for PBG-D and PBG-D-I complex, respectively. Some properties of the isolated enzymes were studied. Molecular mass determination gave a value of 40,000 Da for PBG-D and 50,000 Da for the complex. Both enzymes exhibited classical Michaelis-Menten kinetics. Km and Vmax parameters were estimated. The effect of several divalent cations, ammonia and thiol reagents was also investigated. The differential action of some of these chemicals on PBG-D and PBG-D-I system would suggest that PBG-D and isomerase may not be only physically adjacent but actually associated.
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PMID:Studies on uroporphyrinogen biosynthesis in pig liver. 181 18

Growth studies of Helicobacter pylori were performed involving analysis of the bacterium and its microenvironment, to lend insight into the factors responsible for the morphologic conversion phenomenon. H. pylori converted from bacillary to coccoid forms in broth culture after incubation for 5 days under microaerobic conditions with agitation. This morphologic conversion was paralleled by a dramatic decrease in colony-forming units per milliliter (CFU/ml) and a significant endogenous increase in the pH of the broth culture. In addition, removal of broth cultures from microaerobic conditions after 3 days of incubation resulted in a rapid increase in culture pH, a morphologic conversion, and a concomitant decrease of CFU/ml. These observations suggest an inhibitory effect of basic pH, endogenously produced, on the growth of H. pylori in vitro. Experiments designed to identify the reason for the endogenous increase in culture pH demonstrated that the urease enzyme of H. pylori is not primarily responsible for this phenomenon. Rather, H. pylori appears to produce a deaminase enzyme that is likely responsible for the generation of ammonia, which results in the increase in culture pH, the morphologic conversion, and the loss of culturability observed in vitro. Also indicated is the need for a buffering component (for example, bicarbonate) to maintain pH conditions favorable to the growth of H. pylori.
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PMID:Characterization of the morphologic conversion of Helicobacter pylori from bacillary to coccoid forms. 186 96

Pseudomonas sp. strain ACP is capable of growth on 1-aminocyclopropane-1-carboxylate (ACC) as a nitrogen source owing to induction of the enzyme ACC deaminase and the subsequent conversion of ACC to alpha-ketobutyrate and ammonia (M. Honma, Agric. Biol. Chem. 49:567-571, 1985). The complete amino acid sequence of purified ACC deaminase was determined, and the sequence information was used to clone the ACC deaminase gene from a 6-kb EcoRI fragment of Pseudomonas sp. strain ACP DNA. DNA sequence analysis of an EcoRI-PstI subclone demonstrated an open reading frame (ORF) encoding a polypeptide with a deduced amino acid sequence identical to the protein sequence determined chemically and a predicted molecular mass of 36,674 Da. The ORF also contained an additional 72 bp of upstream sequence not predicted by the amino acid sequence. Escherichia coli minicells containing the 6-kb clone expressed a major polypeptide of the size expected for ACC deaminase which was reactive with ACC deaminase antiserum. Furthermore, a lacZ fusion with the ACC deaminase ORF resulted in the expression of active enzyme in E. coli. ACC is a key intermediate in the biosynthesis of ethylene in plants, and the use of the ACC deaminase gene to manipulate this pathway is discussed.
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PMID:Isolation, sequence, and expression in Escherichia coli of the Pseudomonas sp. strain ACP gene encoding 1-aminocyclopropane-1-carboxylate deaminase. 188 10

The proteolysis of native glucosamine-6-phosphate synthase (Mr 67,000) from Escherichia coli was investigated using two nonspecific and five specific endoproteinases, alpha-chymotrypsin generated two nonoverlapping polypeptides CT1 and CT2 of Mr 40,000 and 27,000 lacking glucosamine-6P synthesizing activity. Amino terminal and carboxy terminal sequence analysis showed that cleavage occurred between positions 240 and 241 of the primary sequence without further degradation. The glutamine amidohydrolase activity was located in the CT2 N-terminal polypeptide which was capable of incorporating 0.7 equivalent of the glutamine site-directed affinity label [2-3H]-N3-(4-methoxyfumaroyl)-diaminopropionic acid indicating that it bears the amidotransferase function. CT1 which displayed a higher reactivity than CT2 for fructose-6P binding contains the ketose/aldose isomerase activity. These data suggest the existence of a hinge structure essential for the catalytically efficient coupling between the ammonia generating domain and the sugar binding domain and support the model recently proposed by Mei and Zalkin in which purF-type amidotransferases contain a glutamine hydrolase domain of approximately 200 amino acids fused to an ammonia-transfer domain.
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PMID:Glucosamine-6-phosphate synthase from Escherichia coli yields two proteins upon limited proteolysis: identification of the glutamine amidohydrolase and 2R ketose/aldose isomerase-bearing domains based on their biochemical properties. 189 18

Ureidoglycolate is an intermediate of allantoin catabolism in ureide-transporting legumes. This report describes the first purification of ureidoglycolate degrading activity (UGDA) from plant tissue in which the enzyme has been separated from urease. The enzyme from developing fruits of Phaseolus vulgaris has been purified 48-fold to give a preparation free of allantoinase and urease activity. UGDA was inhibited by EDTA while the Vmax was increased in the presence of Mn2+. The Km values for ureidoglycolate in the presence and the absence of Mn2+ were 2.0 and 5.4 mM, respectively. In the absence of Mn2+ UGDA was heat labile at 40 degrees C, but in the presence of Mn2+ the activity was stable up to temperatures of 60 degrees C. The Mr of UGDA was determined to be 300,000 by gel filtration chromatography and the pH optimum ranged from pH 7.0 to 8.5. Ammonia was determined to be the nitrogen-containing product of UGDA by a microdiffusion assay. This enzyme should therefore be described as ureidoglycolate amidohydrolase. The activity was shown to be associated with peroxisomes by fractionation of a crude extract on a sucrose density gradient. The products of ureidoglycolate degradation are glyoxylate, ammonia, and presumably carbon dioxide, which can be readily utilized by pathways of metabolism that are known to be present in this organelle.
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PMID:Ureidoglycolate amidohydrolase from developing French bean fruits (Phaseolus vulgaris [L.].). 191 Feb 98

A bacterium capable of utilizing either acetonitrile as the sole source of carbon and nitrogen or biphenyl as the sole source of carbon was isolated from soil and identified as Pseudomonas aeruginosa. The bacterium also utilized other nitriles, amides, and polychlorinated biphenyls (PCBs) as growth substrates. Acetonitrile- or biphenyl-grown cells oxidized these substrates without a lag. In studies with [14C]acetonitrile, nearly 74% of the carbon was recovered as 14CO2 and 8% was associated with the biomass. In studies with [14C]biphenyl, nearly 68% of the carbon was recovered as 14CO2 and nearly 6% was associated with the biomass. Although higher concentrations of acetonitrile as the sole sources of nitrogen inhibited the rates of [14C]biphenyl mineralization, lower concentrations (0.05%, w/v) gave a 77% stimulation in 14CO2 recovery. Pseudomonas aeruginosa metabolized acetonitrile to ammonia and acetic acid and biphenyl to benzoic acid. The bacterium also simultaneously utilized biphenyl as the sole carbon source and acetonitrile as the sole nitrogen source. However, biphenyl utilization increased only after the depletion of acetonitrile. Metabolites of the mixed substrate were ammonia and benzoic acid, which completely disappeared in the later stages of incubation. Nitrile hydratase and amidase were responsible for the transformation of acetonitrile to acetic acid and ammonia.
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PMID:Simultaneous degradation of acetonitrile and biphenyl by Pseudomonas aeruginosa. 191 44


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