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)

Glucosamine-6-phosphate isomerase deaminase from Escherichia coli, a typical allosteric enzyme, becomes less cooperative and 50% inhibited when treated with zinc. This metal cation behaving as a tight-bound and slow partial inhibitor. Modification of a pair of vicinal reactive thiols with some sulfhydryl reagents mimics this effect. On the other hand, sulfhydryl reactivity disappears in the presence of saturating concentrations of Zn2+, which does not modify the kinetics of S-methylated enzyme, a finding that indicates that vicinal thiols are an essential part of the zinc-binding site. Allosteric activation of the deaminase causes trapping of the metal, which cannot be released by dialysis against a buffer containing EDTA. Cadmium and nickel(II) cations also produce a similar effect.
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PMID:Zinc binding and its trapping by allosteric transition in glucosamine-6-phosphate deaminase from Escherichia coli. 211 Nov 70

Large scale purification of human active urinary kallikrein is described. The final preparation was found homogeneous by means of SDS Page electrophoresis, amino acid composition and N-terminal analysis. The apparent molecular weight, determined on SDS Page electrophoresis, was 4.4 X 10(4). Comparative inhibition studies of the kininogenase and the amidase activities pointed out differences in the sensitivity of these two activities. Sodium inhibited amidase activity whereas kininogenase activity required the presence of this cation. In contrast, kininogenase activity was more sensitive to cadmium inhibition than amidase activity. Antibody against purified kallikrein did not completely inhibit amidase activity in crude urine. These discrepancies are consistent with the existence of several amidase activities in urine and also with possibly distinct catalytic sites on the same molecule, accordingly consideration of the methodology used appears very important when comparing results from different studies.
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PMID:Purification of human active urinary kallikrein: comparative inhibition studies of kininogenase and amidolytic activities. 250 80

A new procedure for the isolation of highly purified acylamino acid amidohydrolase from hog kidney is described which allows the preparation of the enzyme with a recovery of about 45%, a 200 fold purification and a spec. activity of 350-500 U. The essential Zn2+ of the enzyme was exchanged for Co2+, Ni2+, Mn2+ and Cd2+, and the kinetic parameters KM, kcat and kcat/KM of the different enzyme species for a series of acetyl-L-amino acids were determined.
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PMID:[New isolation procedure for swine kidney acylase. Kinetics of Co2+, Mn2+, Ni2+ and Cd2+-enzymes]. 651 35

Aminoacylase (EC 3.5.1.14) from Aspergillus oryzae was purified from a commercially available crude material by heat treatment, precipitation by polyethyleneimine and ammoniumsulfate, gel chromatography and preparative disc-gel-electrophoresis. The purified product was homogenous as judged by polyacrylamide gel electrophoresis. SDS-gel electrophoresis, polyacrylamide-gel-gradient electrohoresis, gel chromatography and amino acid analysis demonstrated the enzyme to be composed of two subunits with Mr of 36 600. The kinetic properties of the enzyme were studied with chloracetyl derivatives of alanine, phenylalanine, methionine, leucine, norleucine and tryptophan. The pH optimum of the acylase activity with chloroacetyl-alanine as substrate is at pH 8.5. Acyl derivatives of hydrophobic amino acids are preferred substrates. The enzyme has no dipeptidase activity. Aminoacylase is not inhibited by SH-blocking agents and no SH-groups could be detected with Ellman's reagent in the native and denatured enzyme. The enzyme activity is insensitive to phenylmethylsulfonyl fluoride and N-alpha-p-tosyl-L-lysine chloromethyl ketone. The microbial acylase is zince metallo enzyme. Mental chelating agents are strong inhibitors; it is further inhibited by Cd2+, Mn2+ and activated by Co2+. The properties of pig kidney and Aspergillus acylase are compared.
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PMID:Aminoacylase from Aspergillus oryzae. Comparison with the pig kidney enzyme. 677 95

A thermostable aminoacylase (N-acylamino acid amidohydrolase, EC 3.5.1.14) from Bacillus stearothermophilus was overexpressed in E. coli and characterized with respect to metal content, metal dependence, heat stability, and quaternary structure. Like other enzymes of the aminoacylase family, native aminoacylase contains one Zn2+ ion per subunit. Several other transition metal ions (Co2+, Mn2+ and Cd2+) also sustain aminoacylase activity toward N-acetyl L-alanine with Cd2+ giving the highest turnover number. The stability constants of the respective metal complexes were estimated by activity measurements in metal buffer systems. Co2+ also acts as an activator mainly by lowering the Km for the substrate. These data and CD spectra obtained with the native and the metal-free enzyme suggest a predominantly structural role for the intrinsic metal ion of thermostable aminoacylase. In contrast to previous reports the enzyme behaved as a dimer in analytical gel filtration.
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PMID:Thermostable aminoacylase from Bacillus stearothermophilus: significance of the metal center for catalysis and protein stability. 896 73

The present study was made to isolate and assess some physiological characteristics of root nodule-colonizing fungi. During this study, 17 fungal species were isolated from root nodule samples taken from faba bean plants (Vicia faba L.) collected from different sites at Assiut area (Egypt). The growth of faba bean plants in pots was significantly promoted by soil inoculation with most fungi. Growth was checked in pots with inocula of Cladosporium cladosporioides, Fusarium moniliforme, F: oxysporium, F solani, Macrophominia phaseolina and Rhizoctonia solani which were added separately. All growth-promoting fungi were capable of producing cellulase, pectin lyase, polygalacturonase, protease, urease, amidase, acid phosphatase, alkaline phosphatase and arylsulfatase in growth medium supplemented with the corresponding substrates. Four fungal species, Aspergillus awamori, A. flavus, Penicillium chrysogenum and Trichoderma koningii showed the highest rates of enzyme formation. The effect of the addition of six trace elements to the growth media at 30 micromol/ml on enzyme production revealed some dependency on species, enzyme and metal ion. Cd2+, Hg2+ and Zn2+ generally inhibited enzyme activity. Cu(1+), Fe3+ and Al3+ showed a stimulatory effect. Fungicides (afugan and tilt) and herbicides (brominal and fusilade) at 50 ppm generally promoted enzyme activity, but insecticides (kelthane and fenvalerate) caused some inhibition to enzyme activities. Salinization of the growth media with NaCl strongly inhibited the enzymatic activity of all fungi at concentrations between 0.5 and 1.5%.
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PMID:Physiological aspects of fungi isolated from root nodules of faba bean (Vicia faba L.). 1077 56

Fifteen bacterial strains containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase were isolated from the rhizoplane of pea (Pisum sativum L.) and Indian mustard (Brassica juncea L.) grown in different soils and a long-standing sewage sludge contaminated with heavy metals. The isolated strains were characterized and assigned to various genera and species, such as Pseudomonas brassicacearum, Pseudomonas marginalis, Pseudomonas oryzihabitans, Pseudomonas putida, Pseudomonas sp., Alcaligenes xylosoxidans, Alcaligenes sp., Variovorax paradoxus, Bacillus pumilus, and Rhodococcus sp. by determination of 16S rRNA gene sequences. The root elongation of Indian mustard and rape (Brassica napus var. oleifera L.) germinating seedlings was stimulated by inoculation with 8 and 13 isolated strains, respectively. The bacteria were tolerant to cadmium toxicity and stimulated root elongation of rape seedlings in the presence of 300 microM CdCl2 in the nutrient solution. The effect of ACC-utilising bacteria on root elongation correlated with the impact of aminoethoxyvinylglycine and silver ions, chemical inhibitors of ethylene biosynthesis. A significant improvement in the growth of rape caused by inoculation with certain selected strains was also observed in pot experiments, when the plants were cultivated in cadmium-supplemented soil. The biomass of pea cv. Sparkle and its ethylene sensitive mutant E2 (sym5), in particular, was increased through inoculation with certain strains of ACC-utilising bacteria in pot experiments in quartz sand culture. The beneficial effect of the bacteria on plant growth varied significantly depending on individual bacterial strains, plant genotype, and growth conditions. The results suggest that plant growth promoting rhizobacteria containing ACC deaminase are present in various soils and offer promise as a bacterial inoculum for improvement of plant growth, particularly under unfavourable environmental conditions.
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PMID:Characterization of plant growth promoting rhizobacteria isolated from polluted soils and containing 1-aminocyclopropane-1-carboxylate deaminase. 1154 84

An amidase acting on (R,S)-piperazine-2-tert-butylcarboxamide was purified from Pseudomonas azotoformans IAM 1603 and characterized. The enzyme acted S-stereoselectively on (R,S)-piperazine-2-tert-butylcarboxamide to yield (S)-piperazine-2-carboxylic acid. N-terminal and internal amino acid sequences of the enzyme were determined. The gene encoding the S-stereoselective piperazine-2-tert-butylcarboxamide amidase was cloned from the chromosomal DNA of the strain and sequenced. Analysis of 2.1 kb of genomic DNA revealed the presence of two ORFs, one of which (laaA) encodes the amidase. This enzyme, LaaA is composed of 310 amino acid residues (molecular mass 34 514 Da), and the deduced amino acid sequence exhibits significant similarity to hypothetical and functionally characterized proline iminopeptidases from several bacteria. The laaA gene modified in the nucleotide sequence upstream from its start codon was overexpressed in Escherichia coli. The activity of the recombinant LaaA enzyme in cell-free extracts of E. coli was 13.1 units.mg(-1) with l-prolinamide as substrate. This enzyme was purified to electrophoretic homogeneity by ammonium sulfate fractionation and two column chromatography steps. On gel-filtration chromatography, the enzyme appeared to be a monomer with a molecular mass of 32 kDa. It had maximal activity at 45 degrees C and pH 9.0, and was completely inactivated in the presence of phenylhydrazine, Zn2+, Ag+, Cd2+ or Hg2+. LaaA had hydrolyzing activity toward L-amino acid amides such as L-prolinamide, L-proline-p-nitroanilide, L-alaninamide and L-methioninamide, but did not act on the peptide substrates for the proline iminopeptidases despite their sequence similarity to LaaA. The enzyme also acted S-stereoselectively on (R,S)-piperidine-2-carboxamide, (R,S)-piperazine-2-carboxamide and (R,S)-piperazine-2-tert-butylcarboxamide. Based on its specificity towards L-amino acid amides, the enzyme was named L-amino acid amidase. E. coli transformants overexpressing the laaA gene could be used for the S-stereoselective hydrolysis of (R,S)-piperazine-2-tert-butylcarboxamide.
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PMID:S-stereoselective piperazine-2-tert-butylcarboxamide hydrolase from Pseudomonas azotoformans IAM 1603 is a novel L-amino acid amidase. 1506 72

A novel amidase acting on (R,S)-piperazine-2-tert-butylcarboxamide was purified from Pseudomonas sp. MCI3434 and characterized. The enzyme acted R-stereoselectively on (R,S)-piperazine-2-tert-butylcarboxamide to yield (R)-piperazine-2-carboxylic acid, and was tentatively named R-amidase. The N-terminal amino acid sequence of the enzyme showed high sequence identity with that deduced from a gene named PA3598 encoding a hypothetical hydrolase in Pseudomonas aeruginosa PAO1. The gene encoding R-amidase was cloned from the genomic DNA of Pseudomonas sp. MCI3434 and sequenced. Analysis of 1332 bp of the genomic DNA revealed the presence of one open reading frame (ramA) which encodes the R-amidase. This enzyme, RamA, is composed of 274 amino acid residues (molecular mass, 30 128 Da), and the deduced amino acid sequence exhibits homology to a carbon-nitrogen hydrolase protein (PP3846) from Pseudomonas putida strain KT2440 (72.6% identity) and PA3598 protein from P. aeruginosa strain PAO1 (65.6% identity) and may be classified into a new subfamily in the carbon-nitrogen hydrolase family consisting of aliphatic amidase, beta-ureidopropionase, carbamylase, nitrilase, and so on. The amount of R-amidase in the supernatant of the sonicated cell-free extract of an Escherichia coli transformant overexpressing the ramA gene was about 30 000 times higher than that of Pseudomonas sp. MCI3434. The intact cells of the E. coli transformant could be used for the R-stereoselective hydrolysis of racemic piperazine-2-tert-butylcarboxamide. The recombinant enzyme was purified to electrophoretic homogeneity from cell-free extract of the E. coli transformant overexpressing the ramA gene. On gel-filtration chromatography, the enzyme appeared to be a monomer. It had maximal activity at 45 degrees C and pH 8.0, and was completely inactivated in the presence of p-chloromercuribenzoate, N-ethylmaleimide, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Hg2+, or Pb2+. RamA had hydrolyzing activity toward the carboxamide compounds, in which amino or imino group is connected to beta- or gamma-carbon, such as beta-alaninamide, (R)-piperazine-2-carboxamide (R)-piperidine-3-carboxamide, D-glutaminamide and (R)-piperazine-2-tert-butylcarboxamide. The enzyme, however, did not act on the other amide substrates for the aliphatic amidase despite its sequence similarity to RamA.
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PMID:A novel R-stereoselective amidase from Pseudomonas sp. MCI3434 acting on piperazine-2-tert-butylcarboxamide. 1506 83

An opportunity of formation of ammonia (NH3) in utera endometrium and its influence on exchange of Ca2+ and H+ in plasmalemma of myometrium was investigated. Dissociation of endometrium stroma cells and myocytes suspension was carried from utera of pigs and rats in accordance with the traditional techniques. In suspension of stroma cells a rather high AMP-deaminase activity (53 +/- 2 mmol IMP/hour on 1 mg of protein) was determined. It was demonstrated that ammonia release in extracellular space (measured by the changes of colouring of trinitrobenzolsulfonate acid) was significantly amplified by 1 mM acetylcholine and decreased by 0,1 mM fluoride ions, nonspecific AMP-deaminase inhibitor. It enables to assume a role of AMP-deaminase in formation of NH3 by endometrium stroma cells and its release into extracellular space during acetylcholine stimulation. The addition of ammonia (4 mM) to suspension of myocytes is accompanied by significant increase in pH (measured by the change in BCECF fluorescence) in extracellular and intracellular space, and the last parameter is inhibited by the blockers of passive H+ transport across the membrane: 0,1 mM 4-aminopyridine and tetraethylammonium. It is possible that addition of ammonia-containing solution results in increase in proton gradient on myocyte membrane and in amplification of H+ efflux. The opportunity of stimulation ofacetylcholine-activated passive Ca2+ transport in myocytes by 4 mM NH4+ that was suppressed by 1 mM cadmium and 1 nM nifedipine was also shown using fluorescent probe FURA-2AM. The increase in Ca2+ concentration in cytoplasm in the given conditions is intensively oppressed by protonophore (0.04% 2,4-dinitrophenol) and is effectively amplified by Na+/H+-exchange inhibitor 0,1 mM amyloride. It is possible to assume an amplification of lygand-activated passive Ca2+ transport caused by dispersion of transmembrane proton gradient which exists on plasmalemma and can be increased by ammonia formation in endometrium. The role of diffused from endometrium NH3 in regulation of utera functional activity requires further investigation, however already at this stage it is possible to assume, that NH3 molecules (or ion NH4+) can carry out a role of paracrine regulator in the system endometrium-myometrium.
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PMID:[Possible role of ammonium as a paracrine regulator in the uterine tissue]. 1573 59


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