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:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In Pseudomonas aeruginosa, the synthesis of histidase, urocanase and amidase is severly repressed when succinate is added to a culture growing in pyruvate + ammonium salts medium. When growth is nitrogen-limited, catabolite repression by succinate of histidase and urocanase synthesis does not occur but succinate repression of amidase synthesis persists. Amidase synthesis is not regulated in the same way as histidase synthesis by the availability of other nitrogen compounds for growth. Growth of P. aeruginosa strain PACI in succinate + histidine media is nitrogen-limited since this strain is defective in a histidine transport system. When methyl-ammonium chloride is added to succinate + histidine media, growth inhibition occurs. Mutants isolated from succinate + histidine + methylammonium chloride plates were found to be resistant to catabolite repression by succinate even in ammonium salts media. It is suggested that the hut genes of P. aeruginosa may be regulated in the same way as in Klebsiella aerogenes, by induction by urocanate and activation by either the cyclic AMP-dependent activator protein or by glutamine synthetase.
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PMID:The effect of nitrogen limitation on catabolite repression of amidase, histidase and urocanase in Pseudomonas aeruginosa. 0 23

Mutants of Pseudomonas aeruginosa were isolated that were acetamide-negative in growth phenotype at 41 degrees C and constitutive for amidase synthesis at 28 degrees C. Two mutants were derived from the magno-constitutive amidase mutant PAC111 (C11), and a third from a mutant that had enhanced inducibility by formamide, PAC153 (F6). The three temperature-sensitive mutants produced amidases with the same thermal stabilities as the wild-type enzyme. Cultures growing exponentially at 28 degrees C, synthesizing amidase constitutively, ceased amidase synthesis almost immediately on transfer to 41 degrees C. Cultures growing at 41 degrees C were transferred to 28 degrees C and had a lag of about 0.5 of a generation before amidase synthesis became detectable. Pulse-heating for 10 min at 45 degrees C of a culture growing exponentially at 28 degrees C resulted in a lag of about 0.5 of a generation before amidase synthesis recommenced after returning to 28 degrees C. Acetamide-negative mutants that were unable to synthesize amidase at any growth temperature were isolated from an inducible strain producing the mutant B amidase PAC398 (IB10). Two mutants were examined that gave revertants producing B amidase but with novel regulatory phenotypes. It is suggested that amidase synthesis is regulated by positive control exerted by gene amiR.
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PMID:Positive regulation of amidase synthesis in Pseudomonas aeruginosa. 9 16

Hydroxyurea inhibited growth of Pseudomonas aeruginosa strain AI 3 on media containing either acetanilide (N-phenyl acetamide) or acetamide as sole carbon sources. Mutants resistant to hydroxyurea inhibition of growth on acetanilide (OUCH strains) and acetamide (AmOUCH strains) displayed altered growth properties on various amide media compared with the parent strain AI3. AI3 amidase, which catalyses the initial step in the metabolism of acetanilide and acetamide, was inhibited by hydroxyurea in a time-dependent reaction that was slowly reversible at pH 7.2. Compared with AI3 amidase, amidases from the OUCH mutants were much less sensitive to inhibition by hydroxyurea and showed altered substrate specificities and pH/activity profiles; amidases from the AmOUCH mutants were more sensitive to hydroxyurea inhibition but showed increased activity towards acetamide. Association of resistance to hydroxyurea inhibition with a mutation in the amidase structural gene of strain OUCH 4 was confirmed by transduction.
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PMID:Relationship between mutant amidases of Pseudomonas aeruginosa and hydroxyurea as an inhibitor. 10 40

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

The time-dependent inhibition of amidase from Pseudomonas aeruginosa strain AI 3 by urea, hydroxyurea and cyanate displayed saturation kinetics fitting a model for the reaction sequence in which formation of a complex in a reversible step was followed by an irreversible step. Altered amidases from mutant strains AIU 1N and OUCH 4, selected for their resistance to inhibition of growth by urea and hydroxyurea respectively, had altered kinetic constants for inhibition indicating reduced binding capacity for the inhibitors. The substrate acetamide protected AI 3 amidase against inhibition by urea,.and altered Ki values for inhibition of the mutant amidases were paralleled by alterations in Km values for acetamide indicating that urea acted at the active site. Inhibition of AI 3 amidase involved the binding of one molecule of urea per molecule of enzyme. Urea inhibited amidase slowly regained activity at pH 7.2 through release of urea.
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PMID:Inhibition of the aliphatic amidase from Pseudomonas aeruginosa by urea and related compounds. 11 May 89

Mitomycin C induced a pyocinogenic Pseudomonas aeruginosa P15 to produce a bacteriolytic enzyme, PR1-lysozyme, together with pyocin R1. No significant accumulation of the enzyme was observed inside the induced cells. The enzyme was partially purified by acrinol treatment and Amberlie CG-50 column chromatography. The mode of action of the enzyme on the host bacterial cells as well as on Micrococcus lysodeikticus cells or peptidoglycan isolated from Salmonella typhimurium, was compared with that of hen egg-white lysozyme or phage lambda-lysozyme. It is suggested that PR1-lysozyme should be classified as a glycosidase, rather than an amidase or an endopeptidase.
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PMID:Induction of bacteriolytic enzyme from pyocinogenic Pseudomonas aeruginosa and its enzymatic properties. 11 82

A family of mutant amidases has been derived by experimental evolution of the aliphatic amidase of Pseudomonas aeruginosa strain PAC1. Mutation amiE16, in the structural gene for the enzyme, results in the production of the mutant B amidase by strain B6. This strain, unlike the wild-type, can utilize butyramide for growth. Strain B6 gave rise by a single mutational event to strain V9, utilizing valeramide, and strain PhB3, utilizing phenylacetamide. Strain V9 was not itself able to utilize phenylacetamide but gave rise by mutation to the phenylacetamide-utilizing mutant PhV1. Peptide 108 was isolated from chymotryptic digests of mutant amidases from strains B6, PhB3 and PhV1, but could not be detected in chymotryptic digests of the wild-type amidase. The sequence of peptide 108 was established as Met-Arg-His-Gly-Asp-Ile-Phe. Thermolytic digests of mutant amidases from strains B6, PhB3, PhV1 and V9 were compared with digests of the wild-type amidase. A peptide of the composition Met, Arg, His, Gly2, Asp3, Ile, Ser3, Thr, Val was found in the digest of the wild-type amidase and was replaced in the digests of the mutant amidases by a peptide of the composition Met, Arg, His, Gly2, Asp3, Ile, Ser3, Thr, Val, Phe. Mutation amiE16 is common to the four mutant enzymes and can be accounted for by the mutation Ser leads to Phe. The sequence of the chymotryptic peptide corresponds with the N-terminal sequence of the amidase protein, and can also be related to the thermolysin peptides. It is concluded that mutation amiE16 is a Ser leads to Phe change at position 7 from the N-terminus and the effect of this on the enzyme conformation is discussed.
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PMID:Molecular basis of altered enzyme specificities in a family of mutant amidases from Pseudomonas aeruginosa. 11 34

Synthesis of the Pseudomonas aeruginosa aliphatic amidase was repressed severely by succinate and malate and less severely by glucose, acetate or lactate. Amidase synthesis in inducible and constitutive strains was stimulated by cyclic AMP, which also gave partial relief to catabolite repression produced by the addition of lactate to cultures growing in pyruvate medium. Mutants which were resistant to catabolite repression were isolated from succinate+lactamide medium.
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PMID:Catabolite repression of Pseudomonas aeruginosa amidase: the effect of carbon source on amidase synthesis. 17 Mar 65

Among mutants of Pseudomonas aeruginosa isolated from fluoroacetamide medium were some which synthesized amidase at about 5% of the rate of the parent constitutive strain, PAC101. Seven fluoroacetamide-resistant mutants with low amidase activity gave rise to secondary mutant strains on succinate+butyramide plates. One appeared to be an 'up-promotor' mutant and synthesized amidase at a high rate. This mutant, PAC433, was not stimulated by cyclic-AMP and was much less sensitive to catabolite repression by succinate. The mutation conferring resistance to catabolite repression was cotransduced at a frequency of 96% (26/27) with the amidase genes amiR, amiE. Five other revertants had catabolite repression-resistance mutations which were linked to the amidase genes and these also were probably promotor mutants. One strain had a mutation conferring resistance to catabolite repression which was unlinked to the amidase genes.
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PMID:Catabolite repression of Pseudomonas aeruginosa amidase: isolation of promotor mutants. 17 Mar 66

Allantoinase (allantoin amidohydrolase, EC 3.5.2.5.) and allanoicase (allantoate amidinohydrolase, EC 3.5.3.4) of Pseudomonas aeruginosa are inducible enzymes, whose syntheses are enhanced by the presence of allantoin, allantoate, ureidoglycolate, N-carbamoyl-L-asparagine, N-carbamoyl-L-aspartate, hydantoate, and diureidomethane. For each compound a specific ratio between the activities of allantoinase and allantoicase was obtained. The synthesis of these enzymes is not coordinately controlled. N-Carbamoyl-L-aspartate, hydantoate, and diureidomethane are gratuitous inducers.
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PMID:Allantoinase and allantoicase synthesis in Pseudomonas aerguinosa. 40 22


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