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

Penicillin amidase, alpha-chymotrypsin and urease have been immobilized in water-soluble nonstoichiometric polyelectrolyte complexes (N-PEC). N-PEC are formed by modified poly(N-ethyl-4-vinyl-pyridinium bromide) (polycation) and excess poly(methylacrylic acid) (polyanion). N-PEC are a new class of polymers capable, characteristically, of phase transitions solution in equilibrium precipitate induced by slight change in pH or ionic strength. Neither the chemical structure of the carrier nor the number of cross-linkages between an enzyme and a carrier change on phase transition. That gives an unique opportunity to elucidate the difference between enzymes immobilized on water-soluble and water-insoluble supports. A detailed study of the phase transition effect on thermal stability of the enzymes and protein-protein interactions has been carried out. The following effects were found. Pronounced thermal stabilization of penicillin amidase and urease may be achieved on two conditions: the enzyme is in the precipitate; (b) the enzyme is linked to the N-PEC nucleus. Then the thermal stability of N-PEC-bound penicillin amidase increases 7-fold at pH 5.7, 60 degrees C, and 300-fold at pH 3.1, 25 degrees C, compared to the native enzyme. For urease, the thermal stabilization increases 20-fold at pH 5.0, 70 degrees C. The localization of enzyme on N-PEC has been established by titration of alpha-chymotrypsin bound to a polycation or polyanion with basic pancreatic trypsin inhibitor. Both in solution (pH 6.1) and in N-PEC precipitate (pH 5.7), an alpha-chymotrypsin molecule bound to a polyanion is fully exposed to the solution. If the enzyme is bound to a polycation, only 20% of alpha-chymotrypsin molecules in the precipitate and 40% in solution retain their ability for protein-protein interactions. This means that a polycation-bound enzyme is localized in the hydrophobic nucleus of the complex, whereas the polyanion-bound enzyme sits on the hydrophilic shell of the complex. On pH-induced phase transition (pH decreases from 6.1 to 5.7), there occurs a stepwise decrease in penicillin amidase activity which is due to a 9.8-fold increase in the Km for 2-nitro-4-phenylacetamidobenzoic acid. Change of the catalytic activity and thermal stability of N-PEC-bound penicillin amidase is fully reversible and reproducible. Such soluble-insoluble immobilized enzymes with controllable thermal stability and activity may be used for simulating events in vivo and in biotechnology.
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PMID:Enzymes in polyelectrolyte complexes. The effect of phase transition on thermal stability. 397 68

Various 5-substituted 2'-deoxyuridine (dUrd), 2'-deoxycytidine (dCyd), 1-beta-D-arabinofuranosyluracil (araU) and 1-beta-D-arabinofuranosylcytosine (araC) analogues have been investigated for their stimulatory effect on the growth of a thymidylate (dTMP) synthetase-deficient murine mammary carcinoma cell line (FM3A/TS-) that is auxotrophic for thymidine (dThd). Such stimulatory effect may be considered as indicative for the incorporation of the nucleoside analogue into host cell DNA. Based on this premise, several dUrd analogues were found to be incorporated into FM3A/TS- cell DNA (in decreasing order of incorporation): 5-bromo-dUrd greater than 5-chloro-dUrd greater than 5-(3-hydroxy-1-propynyl)-dUrd greater greater than 5-(1-pentynyl)-dUrd approximately 5-(1-propynyl)-dUrd approximately 5-iodo-dUrd greater than 5-(5-carboxy-1-hexenyl)-dUrd greater than 5-(3,3-dimethyl-1-butynyl)-dUrd greater than 5-ethyl-dUrd greater than 5-(5-chloro-1-pentynyl)-dUrd greater than 5-ethynyl-dUrd approximately 5 vinyl-dUrd greater than 5-phenylethynyl-dUrd greater than 5-(5-cyano-1-pentenyl)-dUrd greater than 5-(1-propenyl)-dUrd greater than 5-(1-hexynyl)-dUrd greater than 5-(5-hexyn-1-enyl)-dUrd. Among the 5-substituted dCyd analogues, 5-methyl-dCyd, 5-chloro-dCyd, 5-bromo-dCyd and 5-iodo-dCyd were also found to stimulate cell growth, and are therefore assumed to be incorporated into FM3A/TS- cell DNA. Since the stimulatory effects of these compounds on FM3A/TS- cell proliferation were suppressed in the presence of a Cyd deaminase inhibitor (tetrahydrouridine) or dCMP deaminase inhibitor (2'-deoxytetrahydrouridine), it is surmised that the dCyd analogues are first deaminated to the corresponding dUrd analogues before they are incorporated into DNA. None of the 5-substituted araU or araC analogues tested were able to sustain the growth of FM3A/TS- cells. It is postulated, therefore, that these araU or araC analogues are not incorporated to any appreciable extent into the DNA of FM3A/TS- cells, or, if they are incorporated, prevent cell growth. Thus, the dTMP synthetase-deficient FM3A/TS- cell line represents a unique system to distinguish those pyrimidine nucleoside analogues that are able to sustain cell growth and, therefore, assumed to be incorporated into the host cell DNA from those pyrimidine nucleoside analogues that are not.
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PMID:Incorporation of 5-substituted pyrimidine nucleoside analogues into DNA of a thymidylate synthetase-deficient murine FM3A carcinoma cell line. 399 Apr 43

The 3'-C-branched-adenosine and 2'-deoxyadenosine analogues 1-7 were tested as substrate of adenosine deaminase. The 9-(3'-C-ethynyl-beta-D-ribo-pentofuranosyl)adenine 1 and its 2'-deoxy analogue 7 were deaminated by the enzyme while the vinyl and ethyl derivatives 2 and 3 were not. The 9-(3'-C-branched-beta-D-xylo-pentofuranosyl)adenines 4-6 were deaminated by the deaminase.
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PMID:3'-Beta-ethynyl and 2'-deoxy-3'-beta-ethynyl adenosines: first 3'-beta-branched-adenosines substrates of adenosine deaminase. 1067 97

A new enzymatic process is reported, in which penicillin G acylase from Escherichia coli displays a promiscuous activity in catalyzing the Markovnikov addition of allopurinol to vinyl ester.
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PMID:Penicillin G acylase catalyzed Markovnikov addition of allopurinol to vinyl ester. 1587 24

Biotransformations of 3-arylpent-4-enenitriles catalyzed by Rhodococcus erythropolis AJ270, a nitrile hydratase/amidase-containing microbial whole-cell catalyst were studied, and an unusual beta-vinyl effect of the substrate on the biocatalytic efficiency and enantioselectivity of the amidase was observed. While 3-arylpent-4-enenitriles and 3-phenylpentanenitrile were efficiently hydrated by the action of the less R-enantioselective nitrile hydratase, the amidase showed greater activity and higher enantioselectivity against 3-arylpent-4-enoic acid amides than 3-arylpentanoic acid amides. Under very mild conditions, nitrile biotransformations provided an efficient synthesis of highly enantiopure (R)-3-arylpent-4-enoic acids and (S)-3-arylpent-4-enoic acid amides, and their applications were demonstrated by the synthesis of chiral gamma-amino acid, 2-pyrrolidinone, and 2-azepinone derivatives.
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PMID:An unusual beta-vinyl effect leading to high efficiency and enantioselectivity of the amidase, nitrile biotransformations for the preparation of enantiopure 3-arylpent-4-enoic acids and amides and their applications in synthesis. 1713 91

Biotransformations of various functionalized racemic nitriles catalyzed by Rhodococcus erythropolis AJ270, a nitrile hydratase/amidase-containing microbial whole-cell catalyst, were studied. While the nitrile hydratase exhibits high catalytic efficiency but very low enantioselectivity against almost all nitrile substrates examined, the amidase is very sensitive toward the structure of the amides. The release of the steric crowdedness around the stereocenter of the substrates and the introduction of an unsaturated carbon-carbon bond into the substrates led to the significant acceleration of the reaction rate and the dramatic enhancement of the enantioselectivity. Nitrile biotransformations provide a unique and high-yielding synthetic route to highly enantiopure carboxylic acids and amides functionalized with an allyl, propargyl, allenyl, or vinyl group. The synthetic applications have been demonstrated by the synthesis of enantiopure heterocyclic compounds including iodoenol gamma-lactone, gamma-lactam, and 3-allyl-1-phenyl-3,4-dihydro-1H-quinolin-2-one derivatives.
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PMID:Remarkable electronic and steric effects in the nitrile biotransformations for the preparation of enantiopure functionalized carboxylic acids and amides: implication for an unsaturated carbon-carbon bond binding domain of the amidase. 1760 98

A zinc-dependent acylase, D-aminoacylase from Escherichia. Coli, displays a promiscuous activity to catalyze the carbon-carbon bond formation reaction of 1,3-dicarbonyl compounds to methyl vinyl ketone in organic media.
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PMID:Promiscuous zinc-dependent acylase-mediated carbon-carbon bond formation in organic media. 1771 84

Catheter-associated infections still represent a challenging thread because of the likelihood of biofilm formation. The aim of this work was the surface modification of catheters to immobilize lysozyme and acylase under mild conditions while preserving antimicrobial and anti-quorum sensing performances. Glycidyl methacrylate (GMA) was grafted onto poly(vinyl chloride) (PVC) catheters by a pre-irradiation method. The effects of monomer concentration, pre-irradiation dose, reaction time, monomer concentration and reaction temperature were investigated. The grafting process was monitored using FTIR-ATR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and swelling data. Lysozyme was directly immobilized onto PVC-g-GMA maintaining the hydrolytic activity, which hindered Staphylococcus aureus adhesion. For acylase immobilization, the PVC-g-GMA catheters were reacted with ethylenediamine and glutaraldehyde in order to facilitate acylase covalent binding. Free acylase in solution demonstrated notably capability to act as quorum sensing inhibitor, as observed using Chromobacterium violaceum as biosensor, by degrading a wide variety of acylated homoserine lactones (AHLs), including those produced by Pseudomonas aeruginosa and Acinetobacter baumannii. Acylase-immobilized PVC-g-GMA catheters were challenged against degradation of AHLs and the activity monitored using both the biosensor and HPLC-MS. Relevantly, the functionalized catheters completely degraded all tested AHL signals, opening new ways of preventing biofilm formation on medical devices.
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PMID:Immobilization of antimicrobial and anti-quorum sensing enzymes onto GMA-grafted poly(vinyl chloride) catheters. 3063 17