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)

The amidase activity of bacteria possessing a high nitrilase activity was found to display the same spectrum although the bacteria may belong to different taxonomic groups, Bacillus, Bacteridium, Micrococcus, Brevibacteriun. The spectrum of amidase activity, although very broad, is more restricted than that of nitrilase activity. Internal amides as well as vinyl-bound amides are not hydrolyzed.
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PMID:Amidase activity of some bacteria. 94 36

R-(-)-Mandelic acid was produced from racemic mandelonitrile by Alcaligenes faecalis ATCC 8750. Ammonium acetate or L-glutamic acid as the carbon source and n-butyronitrile as the inducer in the culture medium were effective for bacterial growth and the induction of R-(-)-mandelic acid-producing activity. The R-(-)-mandelic acid formed from mandelonitrile by resting cells was present in a 100% enantiomeric excess. A. faecalis ATCC 8750 has an R-enantioselective nitrilase for mandelonitrile and an amidase for mandelamide. As R-(-)-mandelic acid was produced from racemic mandelonitrile in a yield of 91%, whereas no S-mandelonitrile was left, the S-mandelonitrile remaining in the reaction is spontaneously racemized because of the chemical equilibrium and is used as the substrate. Consequently, almost all the mandelonitrile is consumed and converted to R-(-)-mandelic acid. R-(-)-Mandelic acid was also produced when benzaldehyde plus HCN was used as the substrate.
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PMID:Production of R-(-)-mandelic acid from mandelonitrile by Alcaligenes faecalis ATCC 8750. 166 Jun 99

A bacterium capable of utilizing acetonitrile (methyl cyanide) as the sole source of carbon and nitrogen was isolated from soil and identified as Pseudomonas aeruginosa. This bacterium could also utilize and oxidize numerous lower-mol-wt nitrile compounds and their corresponding amides as growth substrates. A metabolite of acetonitrile in the culture medium was determined to be ammonia. The accumulation of ammonia in the culture medium was proportional to the concentration of the substrate and the inoculum. Cell extracts of the bacterium contained activities corresponding to nitrile aminohydrolase (E C 3.5.5.1) and amidase (E C 3.5.1.4), which regulate the degradation of acetonitrile. Both enzymes were inducible and hydrolyzed a wide range of substrates, and it was determined that the specific activity of amidase was far greater than the activity of nitrile aminohydrolase.
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PMID:Degradation of organic cyanides by Pseudomonas aeruginosa. 192 88

Pseudomonas marginalis, capable of utilizing acetonitrile as the sole source of carbon and nitrogen, was isolated from an industrial waste site. P. marginalis metabolized acetonitrile into ammonia and acetate. The minimal inhibitory concentration values of different nitriles and amides for P. marginalis were in the range 5-300 mM. The bacterium was able to transform high-molecular-mass nitrile compounds and their respective amides into ammonia. The data from substrate-dependent kinetics showed that the Km and Vmax values of P. marginalis for acetonitrile were 33 mM and 67 nmol oxygen consumed min-1 (ml cell suspension)-1 respectively. The study with [14C]acetonitrile indicated that nearly 66% of the carbon was released as 14CO2 and 12% was associated with the biomass. The enzyme system involved in the hydrolysis of acetonitrile was shown to be intracellular and inducible. The specific activities of the enzymes nitrile aminohydrolase and amidase were determined in the cell-free extracts of P. marginalis. Both the enzymes could hydrolyze a wide range of nitriles and amides. The present study suggests that the biodegradation of organic nitriles and the bioproduction of organic acids may be achieved with the cells of P. marginalis.
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PMID:Pseudomonas marginalis: its degradative capability on organic nitriles and amides. 754 12

A database search indicated homology between some members of the nitrilase/cyanide hydratase family, Pseudomonas aeruginosa and Rhodococcus erythropolis amidases and several other proteins, some of unknown function. BLOCK and PROFILE searches confirmed these relationships and showed that four regions of the P. aeruginosa amidase had significant homology with corresponding regions of nitrilases. A phylogenetic tree placed the P. aeruginosa and R. erythropolis amidases in a group with nitrilases but separated other amidases into three groups. The active site cysteine in nitrilases is conserved in the P. aeruginosa amidase indicating that Cys166 is the active site nucleophile.
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PMID:Pseudomonas aeruginosa aliphatic amidase is related to the nitrilase/cyanide hydratase enzyme family and Cys166 is predicted to be the active site nucleophile of the catalytic mechanism. 760 22

A conserved amino acid sequence motif was identified in four distinct groups of enzymes that catalyze the hydrolysis of the alpha-beta phosphate bond of ATP, namely GMP synthetases, argininosuccinate synthetases, asparagine synthetases, and ATP sulfurylases. The motif is also present in Rhodobacter capsulata AdgA, Escherichia coli NtrL, and Bacillus subtilis OutB, for which no enzymatic activities are currently known. The observed pattern of amino acid residue conservation and predicted secondary structures suggest that this motif may be a modified version of the P-loop of nucleotide binding domains, and that it is likely to be involved in phosphate binding. We call it PP-motif, since it appears to be a part of a previously uncharacterized ATP pyrophophatase domain. ATP sulfurylases, NtrL, and OutB consist of this domain alone. In other proteins, the pyrophosphatase domain is associated with amidotransferase domains (type I or type II), a putative citrulline-aspartate ligase domain or a nitrilase/amidase domain. Unexpectedly, statistically significant overall sequence similarity was found between ATP sulfurylase and 3'-phosphoadenosine 5'-phosphosulfate (PAPS) reductase, another protein of the sulfate activation pathway. The PP-motif is strongly modified in PAPS reductases, but they share with ATP sulfurylases another conserved motif which might be involved in sulfate binding. We propose that PAPS reductases may have evolved from ATP sulfurylases; the evolution of the new enzymatic function appears to be accompanied by a switch of the strongest functional constraint from the PP-motif to the putative sulfate-binding motif.
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PMID:A P-loop-like motif in a widespread ATP pyrophosphatase domain: implications for the evolution of sequence motifs and enzyme activity. 773 53

The bacterial strain Rhodococcus butanica (ATCC 21197), which exhibits nitrilase and nitrile hydratase/amidase activities, catalyses the enantioselective hydrolysis of racemic naproxen nitrile (R/S)-1 to furnish a moderate enantiomeric excess of (S)-naproxen (S)-3. Racemic naproxen amide (R/S)-2 is not a good substrate for this strain. Resting cells of the newly selected bacterial strain Rhodococcus sp. C3II catalyse the enantioselective hydrolyses of racemic naproxen nitrile (R/S)-1 and naproxen amide (R/S)-2 as well, to give (S)-3 in excellent optical (99% e.e.) and good chemical yields in aqueous medium and in the biphasic system of phosphate buffer/hexane.
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PMID:Enzyme-catalysed enantioselective hydrolysis of racemic naproxen nitrile. 785 80

Simultaneous HPLC determination of bromoxynil, ioxynil and dichlobenil, three arylnitrile herbicides, and their metabolic products in soil extracts and microbiological media is described. Limits of detection (LODs) ranged from 0.56 to 3.97 ppb. Slight modification of the mobile phase composition allowed determination of 13 other aromatic nitriles. Assay of aromatic nitrile hydratase, amidase or nitrilase activities is possible by the method developed.
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PMID:High-performance liquid chromatographic study of the aromatic nitrile metabolism in soil bacteria. 879 29

Mesophilic nitrile-degrading enzymes are widely dispersed in the Bacteria and lower orders of the eukaryotic kingdom. Two distinct enzyme systems, a nitrilase catalyzing the direct conversion of nitriles to carboxylic acids and separate but cotranscribed nitrile hydratase and amidase activities, are now well known. Nitrile hydratases are metalloenzymes, incorporating FeIII or CoII ions in thiolate ligand networks where they function as Lewis acids. In comparison, nitrilases are thiol-enzymes and the two enzyme groups have little or no apparent sequence or structural homology. The hydratases typically exist as alpha beta dimers or tetramers in which the alpha- and beta-subunits are similar in size but otherwise unrelated. Nitrilases however, are usually found as homomultimers with as many as 16 subunits. Until recently, the two nitrile-degrading enzyme classes were clearly separated by functional differences, the nitrile hydratases being aliphatic substrate specific and lacking stereoselectivity, whereas the nitrilases are enantioselective and aromatic substrate specific. The recent discovery of novel enzymes in both classes (including thermophilic representatives) has blurred these functional distinctions. Purified mesophilic nitrile-degrading enzymes are typically thermolabile in buffered solution, rarely withstanding exposure to temperatures above 50 degrees C without rapid inactivation. However, operational thermostability is often increased by addition of aliphatic acids or by use of immobilized whole cells. Low molecular stability has frequently been cited as a reason for the limited industrial application of "nitrilases"; such statements notwithstanding, these enzymes have been successfully applied for more than a decade to the kiloton production of acrylamide and more recently to the smaller-scale production of nicotinic acid, R-(-)-mandelic acid and S-(+)-ibuprofen. There is also a rapidly growing catalog of other potentially useful conversions of complex nitriles in which the regioselectivity of the enzyme coupled with the ability to achieve high conversion efficiencies without detriment to other sensitive functionalities is a distinct process advantage.
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PMID:Biochemistry and biotechnology of mesophilic and thermophilic nitrile metabolizing enzymes. 978 67

The amidase from Rhodococcus rhodochrous J1, which hydrolyzes an amide to an acid and ammonium, was surprisingly found to catalyze the hydrolytic cleavage of the C-N triple bond in a nitrile to form an acid and ammonium stoichiometrically. The amidase exhibited a Km of 3.26 mM for benzonitrile in contrast to that of 0.15 mM for benzamide as the original substrate, but the Vmax for benzonitrile was about 116000 of that for benzamide. A mutant amidase containing alanine instead of Ser195, which is essential for amidase catalytic activity, showed no nitrilase activity, demonstrating that this residue plays a crucial role in the hydrolysis of nitriles as well as amides.
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PMID:The catalytic mechanism of amidase also involves nitrile hydrolysis. 984 47


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