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

---

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

The Bacillus subtilis CwlC and the Bacillus polymyxa var. colistinus CwlV are the cell wall lytic N-acetylmuramoyl-l-alanine amidases in the CwlB (LytC) family. Deletion in the CwlC amidase from the C terminus to residue 177 did not change the amidase activity. However, when the deletion was extended slightly toward the N terminus, the amidase activity was entirely lost. Further, the N-terminal deletion mutant without the first 19 amino acids did not have the amidase activity. These results indicate that the N-terminal half (residues 1-176) of the CwlC amidase, the region homologous to the truncated CwlV (CwlVt), is a catalytic domain. Site-directed mutagenesis was performed on 20 highly conserved amino acid residues within the catalytic domain of CwlC. The amidase activity was lost completely on single amino acid substitutions at two residues (Glu-24 and Glu-141). Similarly, the substitution of the two glutamic acid residues (E26Q and E142Q) of the truncated CwlV (CwlV1), which corresponded to Glu-24 and Glu-141 of CwlC, was critical to the amidase activity. The EDTA-treated CwlV1 did not have amidase activity. The amidase activity of the EDTA-treated CwlV1 was restored by the addition of Zn2+, Mn2+, and Co2+ but not by the addition of Mg2+ and Ca2+. These results suggest that the amidases in the CwlB family are zinc amidases containing two glutamic acids as catalytic residues.
...
PMID:Mutational analysis of catalytic sites of the cell wall lytic N-acetylmuramoyl-L-alanine amidases CwlC and CwlV. 1137 3

The enzyme, glucosamine-6-phosphate isomerase (GNPI) or deaminase (GNPDA) (EC 5.3.1.10), catalyzes the conversion of GNP to fructose-6-phosphate and ammonia, with an aldo/keto isomerization and an amination/deamination. A hamster sperm-derived protein (Oscillin) with high similarity to bacterial GNPI has been proved to be capable of inducing calcium oscillation in eggs at fertilization. GNPI/Oscillin was supposed to be an important factor in starting embryonic development. From the cDNA library of human dendritic cells (DC), we isolated a novel full-length cDNA encoding a 276-amino acid-residue protein that shares high homology with human GNPI/Oscillin. So, the novel molecule is named as GNPI2. The GNPI2 gene consists of seven exons and six introns. It is mapped to chromosome 4. Northern blot analysis indicated that the tissue distribution of GNPI2 mRNA is different from that of human GNPI or Oscillin mRNA. GNPI2 is ubiquitously expressed in most of human tissues with high expression in testis, ovary, placenta, and heart. Like GNPI, the recombinant GNPI2 has been proved to have the enzymatic activity to catalyze the conversion of GNP to fructose-6-phosphate. Our results indicated that GNPI2 is a novel protein with definite function as a GNPI.
...
PMID:Cloning and functional characterization of GNPI2, a novel human homolog of glucosamine-6-phosphate isomerase/oscillin. 1261 32

Analysis of the nitrile hydratase gene cluster involved in nitrile metabolism of Pseudomonas chlororaphis B23 revealed that it contains one open reading frame encoding aldoxime dehydratase upstream of the amidase gene. The amino acid sequence deduced from this open reading frame shows similarity (32% identity) with that of Bacillus phenylacetaldoxime dehydratase (Kato, Y., Nakamura, K., Sakiyama, H., Mayhew, S. G., and Asano, Y. (2000) Biochemistry 39, 800-809). The gene product expressed in Escherichia coli catalyzed the dehydration of aldoxime into nitrile. The Pseudomonas aldoxime dehydratase (OxdA) was purified from the E. coli transformant and characterized. OxdA shows an absorption spectrum with a Soret peak that is characteristic of heme, demonstrating that it is a hemoprotein. For its activity, this enzyme required a reducing reagent, Na2S2O4, but did not require FMN, which is crucial for the Bacillus enzyme. The enzymatic reaction was found to be catalyzed when the heme iron of the enzyme was in the ferrous state. Calcium as well as iron was included in the enzyme. OxdA reduced by Na2S2O4 had a molecular mass of 76.2 kDa and consisted of two identical subunits. The kinetic parameters of OxdA indicated that aliphatic aldoximes are more effective substrates than aromatic aldoximes. A variety of spectral shifts in the absorption spectra of OxdA were observed upon the addition of each of various compounds (i.e. redox reagents and heme ligands). Moreover, the addition of the substrate to OxdA gave a peak that would be derived from the intermediate in the nitrile synthetic reaction. P. chlororaphis B23 grew and showed the OxdA activity when cultured in a medium containing aldoxime as the sole carbon and nitrogen source. Together with these findings, Western blotting analysis of the extracts using anti-OxdA antiserum revealed that OxdA is responsible for the metabolism of aldoxime in vivo in this strain.
...
PMID:Novel aldoxime dehydratase involved in carbon-nitrogen triple bond synthesis of Pseudomonas chlororaphis B23. Sequencing, gene expression, purification, and characterization. 1277 27

Cell extracts of Agrobacterium tumefaciens, immobilised in calcium alginate beads, had a 7-fold increase in N-carbamoylase (N-carbamylamino acid amidohydrolase E.C. 3.5.1) activity on reaction with N-carbamylglycine. The hydantoinase (dihydropyrimidinase E.C. 3.5.2.2) and N-carbamoylase activities remained stable over 4 weeks storage at 4 degrees C relative to the non-immobilised enzymes, with the hydantoinase activity showing a 5-fold increase in activity relative to the non-immobilised hydantoinase. The pH optima of the immobilised hydantoinase and N-carbamoylase enzymes decreased to pH 7 and pH 8, respectively. The temperature optimum remained at 40 degrees C for the N-carbamoylase enzyme while the hydantoinase activity was optimal at 50 degrees C.
...
PMID:Enhanced hydantoinase and N-carbamoylase activity on immobilisation of Agrobacterium tumefaciens. 1288 9

Penicillin amidase from Alcaligenes faecalis is a recently identified N-terminal nucleophile hydrolase, which possesses the highest specificity constant (kcat/Km) for the hydrolysis of benzylpenicillin compared with penicillin amidases from other sources. Similar to the Escherichia coli penicillin amidase, the A. faecalis penicillin amidase is maturated in vivo from an inactive precursor into the catalytically active enzyme, containing one tightly bound Ca2+ ion, via a complex post-translational autocatalytic processing with a multi-step excision of a small internal pro-peptide. The function of the pro-region is so far unknown. In vitro addition of chemically synthesized fragments of the pro-peptide to purified mature A. faecalis penicillin amidase increased its specific activity up to 2.3-fold. Mutations were used to block various steps in the proteolytic processing of the pro-peptide to obtain stable mutants with covalently attached fragments of the pro-region to their A-chains. These extensions of the A-chain raised the activity up to 2.3-fold and increased the specificity constants for benzylpenicillin hydrolysis mainly by an increase of the turnover number (kcat).
...
PMID:Fragments of pro-peptide activate mature penicillin amidase of Alcaligenes faecalis. 1462 60

The chemoenzymatic route to 2-deoxy-2-propionamido-D-mannose (1b), 2-butyramido-2-deoxy-D-mannose (2b) and 2-deoxy-2-phenylacetamido-D-mannose (3b) involved N-acylation of 2-amino-2-deoxy-D-glucose followed by alkaline C-2 epimerization and selective microbial removal of the epimers with gluco-configuration. The latter step employed whole cells of Rhodococcus equi A4 able to degrade 2-deoxy-2-propionamido-D-glucose (1a), 2-butyramido-2-deoxy-D-glucose (2a) and 2-deoxy-2-phenylacetamido-D-glucose (3a) but inactive towards the corresponding manno-isomers. The metabolism of the gluco-isomers probably involved phosphorylation and subsequent deacylation. 2-Acetamido-2-deoxy-6-O-phospho-D-glucose amidohydrolase [EC 3.5.1.25] but not 2-acetamido-2-deoxy-D-glucose amidohydrolase was detected in the cell extract, the former enzyme being partially purified (15.8-fold with an overall yield of 18.1% and a specific activity of 0.95 units mg-1 protein). According to SDS-PAGE electrophoresis, gel filtration and mass spectrometry, the enzyme was a monomer with an apparent molecular mass of approximately 42 kDa. The optimum temperature and pH of the enzyme were 60 degrees C and 8.0-9.0, respectively. 2-Acetamido-2-deoxy-6-O-phospho-D-glucose and 2-acetamido-2-deoxy-6-O-sulfo-D-glucose but not 2-acetamido-2-deoxy-1-O-phospho-D-glucose or 2-acetamido-2-deoxy-D-glucose were substrates of the enzyme. Its activity was slightly inhibited by the addition of 1 mM Al3+, Ca2+, Co2+, Cu2+, Mn2+ or Zn2+ and activated by 1 mM Mg2+. The concentrated enzyme is highly stable at 4 degrees C in the presence of 0.1 M ammonium sulfate.
...
PMID:A chemoenzymatic route to mannosamine derivatives bearing different N-acyl groups. 1560 34

One plausible hypothesis for selective neuronal death in sporadic amyotropic lateral sclerosis (ALS) is excitotoxicity mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors, which are a subtype of ionotropic glutamate receptors. The Ca2+ conductance of AMPA receptors differs markedly depending on whether the GluR2 (or GluR-B) subunit is a component of the receptor. The properties of GluR2 are generated posttranscriptionally by RNA editing at the Q/R site in the putative second membrane domain (M2), during which the glutamine (Q) codon is substituted by an arginine (R) codon. AMPA receptors containing the unedited form of GluR2Q have high Ca2+ permeability in contrast to the low Ca2+ conductance of those containing the edited form of GluR2R. The role of Ca(2+)-permeable AMPA receptors, particularly GluR2 Q/R site RNA editing status, in neuronal death has been clearly demonstrated both in mice deficient in editing at the GluR2 Q/R site and in mice transgenic for an artificial Ca(2+)-permeable GluR2 subunit. We analyzed the expression level of mRNA of each AMPA receptor subunit in individual motor neurons, as well as the editing efficiency of GluR2 mRNA at the Q/R site in the single neuron level in control subjects and ALS cases. There was no significant difference as to the expression profile of AMPA receptor subunits or the proportion of GluR2 mRNA to total GluRs mRNA between normal subjects and ALS cases. By contrast, the editing efficiency varied greatly, from 0% to 100%, among the motor neurons of each individual with ALS, and was not complete in 44 of them (56%), whereas it remained 100% in normal controls. In addition, GluR2 editing efficiency was more than 99% in the cerebellar Purkinje cells of ALS, spinocerebellar degeneration and normal control groups. Thus, GluR2 underediting occurs in a disease specific and region selective manner. GluR2 modification by RNA editing is a biologically crucial event for neuronal survival, and its deficiency is a direct cause of neuronal death. Therefore, marked reduction of RNA editing in ALS motor neurons may be a direct cause of the selective motor neuron death seen in ALS. It is likely that the molecular mechanism underlying the deficiency in RNA editing is a reduction in the activity of ADAR2, a double- strand RNA specific deaminase. The restoration of this enzyme activity in ALS motor neurons may open the novel strategy for specific ALS therapy.
...
PMID:Deficient RNA editing of GluR2 and neuronal death in amyotropic lateral sclerosis. 1562 11

Although plant growth-promoting rhizobacteria (PGPR) have been reported to influence plant growth, yield and nutrient uptake by an array of mechanisms, the specific traits by which PGPR promote plant growth, yield and nutrient uptake were limited to the expression of one or more of the traits expressed at a given environment of plant-microbe interaction. We selected nine different isolates of PGPR from a pool of 233 rhizobacterial isolates obtained from the peanut rhizosphere on the basis of ACC-deaminase activity. The nine isolates were selected, initially, on the basis of germinating seed bioassay in which the root length of the seedling was enhanced significantly over the untreated control. All the nine isolates were identified as Pseudomonas spp. Four of these isolates, viz. PGPR1, PGPR2, PGPR4 and PGPR7 (all fluorescent pseudomonads), were the best in producing siderophore and indole acetic acid (IAA). In addition to IAA and siderophore-producing attributes, Pseudomonas fluorescens PGPR1 also possessed the characters like tri-calcium phosphate solubilization, ammonification and inhibited Aspergillus niger and A. flavus in vitro. P. fluorescens PGPR2 differed from PGPR1 in the sense that it did not show ammonification. In addition to the traits exhibited by PGPR1, PGPR4 showed strong in vitro inhibition to Sclerotium rolfsii. The performances of these selected plant growth-promoting rhizobacterial isolates were repeatedly evaluated for 3 years in pot and field trials. Seed inoculation of these three isolates, viz. PGPR1, PGPR2 and PGPR4, resulted in a significantly higher pod yield than the control, in pots, during rainy and post-rainy seasons. The contents of nitrogen and phosphorus in soil, shoot and kernel were also enhanced significantly in treatments inoculated with these rhizobacterial isolates in pots during both the seasons. In the field trials, however, there was wide variation in the performance of the PGPR isolates in enhancing the growth and yield of peanut in different years. Plant growth-promoting fluorescent pseudomonad isolates, viz. PGPR1, PGPR2 and PGPR4, significantly enhanced pod yield (23-26%, 24-28% and 18-24%, respectively), haulm yield and nodule dry weight over the control in 3 years. Other attributes like root length, pod number, 100-kernel mass, shelling out-turn and nodule number were also enhanced. Seed bacterization with plant growth-promoting P. fluorescens isolates, viz. PGPR1, PGPR2 and PGPR4, suppressed the soil-borne fungal diseases like collar rot of peanut caused by A. niger and PGPR4 also suppressed stem rot caused by S. rolfsii. Studies on the growth patterns of PGPR isolates utilizing the seed leachate as the sole source of C and N indicated that PGPR4 isolate was the best in utilizing the seed leachate of peanut, cultivar JL24. Studies on the rhizosphere competence of the PGPR isolates, evaluated on the basis of spontaneous rifampicin resistance, indicated that PGPR7 was the best rhizoplane colonizer and PGPR1 was the best rhizosphere colonizer. Although the presence of growth-promoting traits in vitro does not guarantee that an isolate will be plant growth promoting in nature, results suggested that besides ACC-deaminase activity of the PGPR isolates, expression of one or more of the traits like suppression of phytopathogens, solubilization of tri-calcium phosphate, production of siderophore and/or nodulation promotion might have contributed to the enhancement of growth, yield and nutrient uptake of peanut.
...
PMID:Growth promotion and yield enhancement of peanut (Arachis hypogaea L.) by application of plant growth-promoting rhizobacteria. 1564 84

Escherichia coli NCIM 2569 was evaluated for its potential for amidase production under submerged fermentation. Among the various amide compounds screened, maximum substrate specificity and enzyme yield (8.1 U/mL) were obtained by using 1% acetamide. Fermentation was carried out at 30 degrees C in shake-flask culture under optimized process conditions. A maximum of 0.52 U/mL of intracellular amidase activity was also obtained from cells incubated for 24 h. Studies were also performed to elucidate the optimal conditions (gel concentration, initial biomass, curing period of beads, and calcium ion concentration in the production medium) for immobilization of whole cells. By using E. coli cells entrapped in alginate, a maximum of 6.2 U/mL of enzyme activity was obtained after 12 h of incubation under optimized conditions. Using the immobilized cells, three repeated batches were carried out successfully, and 85% of the initial enzyme activity was retained in the second and third batches. The study indicated that the immobilized E. coli cells offered certain advantages such as less time for maximum enzyme production, more stability in the enzyme production rate, and repeated use of the biocatalyst.
...
PMID:Comparative study of amidase production by free and immobilized Escherichia coli cells. 1569 39

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.
...
PMID:[Possible role of ammonium as a paracrine regulator in the uterine tissue]. 1573 59


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---