Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

L-alpha-aminocaprolactam hydrolase possessing the L lysine amidase activity was isolated from Klebsiella aerogenes and purified. The procedure of enzymes purification included cell destruction on USDN-I, fractionation by ammonium sulfate, gel chromatography on G-200. The preparation of the purified enzyme possessed specific activity of 50 mumol of lysin per 1 mg of protein per hour. Km was 2.6 mM in case of phosphate buffer (ph 7.2) for I-alpha-aminocaprolactam. Besides L-alpha-aminocaprolactam the enzyme hydrolyses lysine amide, leucine amide tryptophanamide. Magnesium ions are necessary for manifestation of catalytic activity of the enzyme.
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PMID:[Isolation and various properties of alpha-aminocaprolactam hydrolase from Klebsiella aerogenes]. 151 39

The effects of prolonged ischaemia and subsequent reperfusion during and after reconstructive microsurgery on energy metabolism were studied. Repeated skeletal muscle biopsies were taken and analysed for high energy phosphates and their degradation products by high performance liquid chromatography and for lactate by a fluorometric procedure. Moderate changes in adenine nucleotides occurred during the first 4 h of ischaemia. After 6 h of ischaemia, when the creatine phosphate store was almost depleted and the lactate level had increased to 111 mmol kg-1 dry muscle, ATP content decreased and inosine monophosphate started to accumulate. The inosine monophosphate accumulation was however small, in spite of a high lactate level, which suggests that the increase in H+ associated with lactate formation is not important for the activation of AMP-deaminase during the present conditions. In spite of the accelerating metabolic deterioration during the later period of ischaemia, the reperfusion of the muscle resulted in a rapid normalization of all the studied metabolites, thereby indicating a rapid restoration of the muscle energy stores.
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PMID:Small accumulation of inosine monophosphate (IMP) despite high lactate levels in latissimus dorsi during transplantation. 191 40

Peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase F(PNGase F) from Flavobacterium meningosepticum is a highly useful enzyme for the structural analysis of N (asparagine)-linked carbohydrate chains derived from glycoproteins. The enzyme was enriched using a published procedure [Tarentino AL, Gomez CM, Plummer TH, Jr (1984) Biochemistry 1985:4665-71; Tarentino AL, Plummer TH, Jr (1987) Methods Enzymol 138:770-78] and further purified by hydrophobic interaction HPLC on a weak hydrophobic TSK-Ether column from which it was eluted by a decreasing gradient of 1.7 M ammonium sulphate in 100 mM sodium phosphate, pH 7.0, containing 5 mM EDTA. To determine the optimal conditions for a complete deglycosylation of glycoproteins by PNGase F, experiments were performed with human alpha 1-acid glycoprotein, because the five complex type carbohydrate chains are quite resistant to enzymic hydrolysis. The influence of different detergents on the enzyme reaction was studied. Complete deglycosylation of human alpha 1-acid glycoprotein was achieved by the use of 60 mU/ml PNGase F in 0.25 M sodium phosphate buffer, pH 8.6, containing 0.2% (w/v) SDS, 20 mM mercaptoethanol and 0.5% Mega-10.
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PMID:Optimized deglycosylation of glycoproteins by peptide-N4-(N-acetyl-beta-glucosaminyl)-asparagine amidase from Flavobacterium meningosepticum. 213 46

An early event in the nephrotoxicity of haloalkene cysteine conjugates is their metabolism by cysteine conjugate beta-lyase to generate a reactive "thiol moiety" which binds to protein. This reactive metabolite(s) has been reported to cause mitochondrial dysfunction. We have examined the effect of three haloalkene cysteine conjugates on the activity of rat renal cortical cytosolic glutathione reductase and mitochondrial lipoyl dehydrogenase, two enzymes which have been reported to be inhibited by S-(1,2-dichlorovinyl)-L-cysteine (DCVC) in the liver. N-Acetyl-S-(1,2,3,4,4-pentachloro-1,3-butadienyl)-L- cysteine (N-acetyl PCBC) produced a time- and concentration-dependent inhibition of glutathione reductase and kinetic studies showed that the inhibition was noncompetitive with a Ki of 215 microM. The enzyme activity from male rat kidney was more sensitive to N-acetyl PCBC than that from female rat kidney. Aminooxyacetic acid, an inhibitor of cysteine conjugate beta-lyase, and bis-p-nitrophenyl phosphate, an amidase inhibitor, blocked the effect of N-acetyl PCBC on glutathione reductase, indicating that metabolism by the cytosol is required to produce enzyme inhibition. S-(1,1,2,2-Tetrafluoroethyl)-L-cysteine (TFEC) and DCVC are also noncompetitive inhibitors of glutathione reductase but are less active than N-acetyl PCBC with Ki's of 2.6 and 6.2 mM for DCVC and TFEC, respectively, DCVC produced a time- and concentration-dependent inhibition of lipoyl dehydrogenase and kinetic studies showed that the inhibition was noncompetitive with a Ki of 762 microM. TFEC and PCBC also inhibit lipoyl dehydrogenase. Aminooxyacetic acid blocked the effect of DCVC, TFEC, and PCBC on lipoyl dehydrogenase, indicating that metabolism by the mitochondrial fraction is required to produce enzyme inhibition. Glutathione reductase activity in the renal cortex of male rats treated with 200 mg/kg hexachloro-1,3-butadiene (HCBD) was inhibited as early as 1 hour after dosing, before signs of marked morphological damage. The activity of lipoyl dehydrogenase was also reduced but was only statistically significant 8 hr after dosing when there was marked renal dysfunction. These findings indicate that the reactive thiol moiety formed by cysteine conjugate beta-lyase cleavage of PCBC can inhibit both glutathione reductase and lipoyl dehydrogenase activities in vivo following HCBD administration. We suggest that such inhibition is a general phenomenon, occurring with diverse and as yet unidentified renal proteins. The critical nature of mitochondrial function and the generation of reactive metabolites within this compartment make this organelle a prime target.
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PMID:The effect of haloalkene cysteine conjugates on rat renal glutathione reductase and lipoyl dehydrogenase activities. 236 Feb 7

Adenylic acid (AMP) deaminase is a "catabolic enzyme" involved in nucleotide degradation, transforming AMP into inosinic acid (IMP). We present a simple method for the determination of the enzyme activity, which combines high sensitivity with requirement of low quantities of lymphocytes. Human lymphocytes were isolated with a Lymphocyte Separation Medium from FLOW and sonicated. After centrifugation at 2,000 rpm x 10 min and treatment with Norit A, the cells were incubated at 37 degrees C with ATP 0.8 mM and 14C-AMP 0.1 mM (specific activity 12 microCi/mumole) in potassium phosphate 100 mM (pH 7.4). 14C-IMP and 14C-AMP were separated through HPLC by an isocratic elution, with 20 mM KH2PO4 (pH 5.5) at a 1.5 ml/min flow rate. Identification of the nucleotides was carried out through retention time, coelution with internal standards: their evaluation by determining the radioactivity of the collected peaks. The enzyme activity is decreased in patients affected by CLL: the decrease is evident only when data are referred to the single cells and not when they are referred to the protein.
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PMID:[Purine metabolism: determination of adenyl deaminase in human lymphocytes]. 239 Feb 25

1-beta-D-Arabinofuranosyl-5-azacytosine (ara-5-aza-Cyd) had potent cytotoxicity against human T-type lymphoblastic cells in culture. When Molt-4 cells were exposed to ara-5-aza-Cyd for 24 h, clonogenic survival was reduced by 50 and 98% at initial concentrations of 10(-7) and 10(-6) M, respectively, compared to 3 X 10(-8) and 10(-6) M, respectively, for the same effect with 1-beta-D-arabinofuranosylcytosine (ara-C). The analogue is chemically unstable, with a t1/2 of 12 h at 37 degrees C in phosphate-buffered saline. ara-5-aza-Cyd is not significantly deaminated by human Cyd-deoxycytidine (dCyd) deaminase, in contrast to ara-C. It is phosphorylated by human cytoplasmic dCyd kinase, with a Km of 55 microM and a relative Vmax of 310% compared to dCyd. The primary metabolite (70%) in Molt-4 cells was identified as ara-5-aza-Cyd triphosphate. Thymidine but not uridine or amino acid incorporation was inhibited by ara-5-aza-Cyd. ara-5-aza-Cyd was incorporated in a dose-dependent manner into DNA, but not RNA, primarily in internucleotide linkage as the original compound. Incorporation into the cellular methanol-insoluble fraction was 3- to 5-fold higher at 8 h than was ara-C incorporation. ara-5-aza-Cyd may have a unique activity against tumor cells resistant to ara-C, particularly where high Cyd-dCyd deaminase activity is a factor. The mode of action, like that of ara-C, is probably mediated through its incorporation into DNA and inhibition of DNA synthesis.
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PMID:Metabolism of 1-beta-D-arabinofuranosyl-5-azacytosine and incorporation into DNA of human T-lymphoblastic cells (Molt-4). 241 96

Of 120 laboratory-maintained strains of Listeria monocytogenes and two of L. ivanovii examined for haemolytic and lipolytic activity, 62 exhibited haemolytic activity alone, 20 of these showed haemolytic and lipolytic activity and 40 had neither activity. The L. ivanovii strains showed both activities. The results indicated a relationship between haemolysin production and lipolytic activity which was not explained by the serotype of the organism. In addition, the following hydrolytic activities were detected in the cell-free growth media of strains L. monocytogenes Boldy and L. ivanovii (formerly L. monocytogenes) Type 5 (substrates acted upon are given in parentheses): acid phosphate (4-nitrophenylphosphate, naphthyl phosphate, glycerophosphate, phosphorylcholine and GTP); neutral phosphatase (4-nitrophenylphosphate, naphthyl phosphate, phosphorylcholine, NADP and UDPG); phosphodiesterase (bis-4-nitrophenylphosphate, ATP and NADP); NADase (NAD); phospholipase C (4-nitrophenylphosphoryl-choline, phosphatidyl choline and ethanolamine, and sphingomyelin); and lipase and esterase (triacetin, tributyrin, triolein, naphthyl-laurate,-myristate,-caprylate,-palmitate and -oleate, 4-nitrophenyl-acetate-laurate and Tween 80). The preparations also showed weak catalase activity. No evidence was found for the presence of RNAase, DNAase, peptidase/amidase, phosphoamidase, alpha-amylase, glucosidase, galactosidase, pyranosidase or glucose aminidase.
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PMID:Haemolysins and extracellular enzymes of Listeria monocytogenes and L. ivanovii. 250 86

Rat liver L-serine dehydratase (E.C.4.2.1.13) catalyzes the deamination both of L-serine and of L-threonine. These reactions show different rates and, at this moment, the "preferential" substrate of the enzyme is not clear. We have analysed, in various experimental conditions, the behaviour of the deaminase reaction toward the two substrates. From the obtained data, it is evident that at lower pH values L-serine and at higher pH values L-threonine, are the preferred substrates, respectively. A peculiar behaviour is shown by Km values, because they are different by changing the pH in the assay mixtures, and changes are related to the presence of pyridoxal-5'-phosphate in the assay mixtures.
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PMID:[Kinetic properties of L-serine dehydratase of the rat liver]. 251 63

Tryptophan deaminase was isolated from Proteus vulgaris and purified. The procedure for enzyme purification included the cell destruction on USD-1, fractionation by ammonium sulphate, gel chromatography on ultragel AcA34, ion exchange chromatography on DEAE-cellulose. A degree of the enzyme purification--95, yield--5.7%. The pH optimum was 7.5, the temperature optimum--47 degrees C. The enzyme molecular weight (105 kD) was estimated by gel chromatography on Sephadex G-200, Km--5.0 mM in the K-phosphate buffer (pH 7.5). The SH groups are supposed to be present in the active site of the enzyme. The enzyme does not accelerate oxidation deamination of phenylalanine and tyrosine.
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PMID:[Isolation and various characteristics of tryptophan deaminase from Proteus vulgaris]. 268 39

By inserting a lambda placMu bacteriophage into gene glmS encoding glucosamine 6-phosphate synthetase (GlmS), the key enzyme of amino sugar biosynthesis, a nonreverting mutant of Escherichia coli K-12 that was strictly dependent on exogenous N-acetyl-D-glucosamine or D-glucosamine was generated. Analysis of suppressor mutations rendering the mutant independent of amino sugar supply revealed that the catabolic enzyme D-glucosamine-6-phosphate isomerase (deaminase), encoded by gene nagB of the nag operon, was able to fulfill anabolic functions in amino sugar biosynthesis. The suppressor mutants invariably expressed the isomerase constitutively as a result of mutations in nagR, the locus for the repressor of the nag regulon. Suppression was also possible by transformation of glmS mutants with high-copy-number plasmids expressing the gene nagB. Efficient suppression of the glmS lesion, however, required mutations in a second locus, termed glmX, which has been localized to 26.8 min on the standard E. coli K-12 map. Its possible function in nitrogen or cell wall metabolism is discussed.
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PMID:Alternative route for biosynthesis of amino sugars in Escherichia coli K-12 mutants by means of a catabolic isomerase. 268 46


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