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)

Absence of AMP-deaminase was demonstrated by histochemical and biochemical methods in a muscle biopsy of a 25-year-old woman with facial and limb girdle myopathy. Venous ammonia failed to rise after ischaemic exercise. This patient further contributes to the variety of clinical pictures associated with AMP-deaminase deficiency. Whereas AMP-deaminase has been shown to play an essential role in the regulation of adenine nucleotide metabolism in the liver, its physiological function in muscle remains uncertain.
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PMID:Myoadenylate deaminase deficiency in a patient with facial and limb girdle myopathy. 616 80

Glucosamine-6-phosphate isomerase (deaminase), (2-amino-2-deoxy-D-glucose-6-phosphate ketol isomerase (deaminating), EC 5.3.1.10) has been purified to homogeneity from Escherichia coli B as judged by several criteria of purity. The procedure included ammonium sulfate fractionation, anion-exchange chromatography and a biospecific affinity chromatography step with N-epsilon-amino-n- caproyl -D-glucosamine 6-phosphate bound to agarose as the ligand, the elution being performed with GlcNAc6 P. The enzyme appears to be an hexamer of about 178 kDa, composed of six subunits of 29 700 +/- 300 Da; the isoelectric point was 6.0-6.1 and the sedimentation constant 9.0 S. The amino-acid composition of the enzyme was determined and a value for E1%275 of 4.55 was calculated. The molecular activity was 1800 s-1 for the deamination reaction and 455 s-1 for the reaction of GlcN6 P formation. A positive homotropic cooperativity was found for both sugar substrates; it was stronger for GlcN6 P in the deamination reaction (Hill number 2.7 at pH 7.7). Ammonia behaved as a Michaelian substrate. Cooperativity was abolished by 0.1 mM GlcNAc6 P; this allosteric modulator activated the reaction in both directions, with a positive K-effect upon both sugar phosphates, but had no effect on Km for ammonia. The initial velocity patterns for the amination reaction were obtained under conditions of hyperbolic kinetics produced by GlcNAc6 P; the Km values for the allosteric substrates were determined under the same conditions, and their dependence upon pH was studied.
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PMID:Purification, molecular and kinetic properties of glucosamine-6-phosphate isomerase (deaminase) from Escherichia coli. 637 29

Concentrations of key metabolites were determined in goldfish red muscle, while muscle and blood before and after direct electrical stimulation of the myotome (60 pulses/min, amplitude 500 mV, 10 msec pulse duration, during 10 min at 20 degrees C). In white muscle, levels of ATP, aspartate and adenylate energy charge are significantly lowered while those of AMP, IMP, NH3, alpha-ketoglutarate, lactate and malate are increased. In red muscle, the only change induced by stimulation is a 160% increase of the lactate level. In white muscle, IMP-accumulation and ammonia production are equal, suggesting the AMP-deaminase reaction to be the major source of muscular ammonia. Activation of white muscle adenylosuccinate synthetase and adenylosuccinase is suggested by the conversion of aspartate into malate during increased energy demand. There is no evidence of ammonia incorporation into alanine, glutamate or glutamine.
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PMID:Goldfish muscle energy metabolism during electrical stimulation. 661 58

1. The liberation of ammonia from adenosine 5'-phosphate (AMP) and adenosine and the release of inorganic phosphate from AMP were investigated in homogenates of bovine and human parotid glands. 2. Adenosine phosphate deaminase (AMP deaminase) was purified from bovine and human parotid glands. The enzyme preparations obtained were free from adenosine deaminase and 5'-nucleotidase activities. 3. AMP incubated with human parotid gland homogenate produced inosine 5'-phosphate, adenosine, inosine and ammonia. The amount of ammonia accumulating in the incubation mixture was equal to the sum of inosine 5'-phosphate plus inosine. 4. These results demonstrate the presence in human parotid of AMP deaminase and adenosine deaminase.
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PMID:Deamination of adenosine 5'-phosphate and adenosine as a possible source of ammonia in human and bovine parotid glands. 724 42

The enzyme 1-aminocyclopropane-1-carboxylate deaminase (ACPC deaminase) from a pseudomonad is a pyridoxal phosphate (PLP) linked catalyst which fragments the cyclopropane substrate to alpha-ketobutyrate and ammonia [Honma, M., & Shimomura, T. (1978) Agric. Biol. Chem. 42, 1825]. Enzymatic incubations in D2O yield alpha-ketobutyrate with one deuterium at the C-4 methyl group and one deuterium at one of the C-3 prochiral methylene hydrogens. Stereochemical analysis of the location of the C-3 deuteron was accomplished by in situ enzymatic reduction to (2S)-2-hydroxybutyrate with L-lactate dehydrogenase and conversion to the phenacyl ester. The C-3 hydrogens of the (2S)-2-hydroxybutyryl moiety are fully resolved in a 250-MHz NMR spectrum. Absolute assignment of 3S and 3R loci was obtained with phenacyl (2S,3S)-2-hydroxy[3-2H]butyrate generated enzymatically by D-serine dehydratase action on D-threonine. ACPC deaminase shows a stereoselective outcome with a 3R:3S deuterated product ratio of 72:28. 2-Vinyl-ACPC is also a fragmentation substrate with exclusive regiospecific cleavage to yield the straight-chain keto acid product 2-keto-5-hexenoate. The D isomer of vinylglycine is processed to alpha-ketobutyrate and ammonia at 8% the Vmax of ACPC, while L-vinylglycine is not a substrate. It is likely that ACPC and D-vinylglycine yield a common intermediate--the vinylglycine-PLP-p-quinoid adduct--which is then protonated sequentially at C-4 and then C-3 to account for the observed deuterium incorporation. The D isomers of beta-substituted alanines (fluoroalanine, chloroalanine, and O-acetyl-D-serine) partition between catalytic elimination and enzyme inactivation. Each shows a different partition ratio, arguing against the common aminoacrylyl-PLP as the inactivating species.
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PMID:Mechanistic studies on the pyridoxal phosphate enzyme 1-aminocyclopropane-1-carboxylate deaminase from Pseudomonas sp. 732 43

Effects of feeding the methane inhibitor, amicloral, and the deaminase inhibitor (DAI), 4,4'-dimethyldiphenyliodonium chloride, at 1,500 and 25 mg/kg of diet, respectively, were investigated in finishing steers. Digestibility and ruminal VFA and ammonia concentrations were measured in six steers per treatment. Organic matter digestibility was increased significantly by amicloral, DAI and amicloral plus DAI. There were no treatment effects on molar proportions of acetic acid or propionic acid, but butyric acid was highest (P < .05) when both additives were fed. Ruminal ammonia concentrations were lower (P < .05) with all three treatment diets. Ninety-six steers were allotted to eight groups, two pens (replicates) per treatment, in a 112-day feedlot study. Neither amicloral nor DAI had any effect on intake or daily gain, although feed efficiency was increased (P > .05) by 9 and 4%, respectively. Feeding amicloral plus DAI lowered intake by 19% (P < .05) and gains by 8% (P > .05) but increased the efficiency of feed utilization by 12% (P < .05).
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PMID:Use of feed additives to reduce ruminal methane production and deaminase activity in steers. 740 58

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

Urea amidohydrolase (urease) was immobilized within poly[di(methoxyethoxyethoxy)phosphazene] (MEEP) hydrogels. This was accomplished by mixing an aqueous solution (pH 7) of the soluble polymer with the enzyme. Films of the conjugate were cast and the solvent removed to yield an MEEP/enzyme composite. The conjugate films were dried in a vacuum and were then cross-linked by exposure to 0.2 or 0.5 Mrad of 60Co gamma-radiation to give an MEEP network with the enzyme entrapped within its matrix. The cross-linked films were sectioned into strips and were washed with pH 7 buffer to remove enzyme adhering to the surface. The films were then allowed to swell to form a hydrogel in pH 7 buffer to which was added a 1.0 M aqueous urea solution. The increase in pH from the conversion of urea to ammonia was monitored over a 24 h period. The immobilized enzyme could be recycled at least five times without significant loss of activity. Several control experiments were also performed by monitoring the pH of buffer solutions that contained hydrogels devoid of entrapped urease, and by monitoring the pH of solutions of the free, non-irradiated and free, irradiated urease after the addition of the urea solution. The polymer-free, irradiated urease lost little to no activity compared with its non-irradiated counterpart. The MEEP gel-immobilized enzyme retained approximately 80% of the activity of the non-irradiated, polymer-free urease.
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PMID:Activity of urea amidohydrolase immobilized within poly[di(methoxyethoxyethoxy)phosphazene] hydrogels. 791 2

Porphobilinogen deaminase (EC 4.3.1.8) has been purified to homogeneity (16,000-fold) from the plant Arabidopsis thaliana in yields of 8%. The deaminase is a monomer of M(r) 35,000, as shown by SDS/PAGE, and 31,000, using gel-filtration chromatography. The pure enzyme has a Vmax. of 4.5 mumol/h per mg and a Km of 17 +/- 4 microM. Determination of the pI and pH optimum revealed values of 5.2 and 8.0 respectively. The sequence of the N-terminus was found to be NH2-XVAVEQKTRTAI. The deaminase is heat-stable up to 70 degrees C and is inhibited by NH3 and hydroxylamine. The enzyme is inactivated by arginine-, histidine- and lysine-specific reagents. Incubation with the substrate analogue and suicide inhibitor, 2-bromoporphobilinogen, results in chain termination and in inactivation.
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PMID:Purification and properties of porphobilinogen deaminase from Arabidopsis thaliana. 819 81

A new method of assaying deaminase activity was established in which methylamine and/or dimethylamine formed from drugs containing N,N-dimethyl or N-methyl group were derivatized with phenylisothiocyanate to phenylthiourea derivatives. After purification with Sep-PAK C18 cartridge, the derivatives were separated by a reversed phase high-performance liquid chromatography monitored by ultraviolet absorption. The recoveries and determination limits of methylamine and dimethylamine were over 55% and about 0.4 nmol/ml of incubation mixture, respectively. The method was used to measure the deaminase activities of liver microsomes of rats, rabbits and guinea pigs for 11 drugs. Of the compounds tested, diphenhydramine and diltiazem are deaminated with microsomes from all the above animal species; rat and rabbit liver microsomes also well deaminated promethazine. Most other drugs such as chlorpromazine, promazine, imipramine, amitriptyline and tetracaine were found to be poor substrates. In general, dimethylamine but not methylamine was the predominant metabolite formed from drugs containing N,N-dimethylamino group. The results also suggested that the deamination of these compounds takes place mainly via a one step mechanism, thus implying that the sequential reaction consisting of N-demethylation and elimination of ammonia is of minor importance. The relation between in vitro deaminase activity and the extent of the in vivo deamination for drugs is discussed.
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PMID:Metabolic formation of dimethylamine and methylamine from basic drugs containing N-methyl group: a newly established chromatographic assay and its application to the determination of deaminase activity. 826 49


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