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)

Evidence is presented that each of the porphyrias represents a different inborn error of metabolism in haem biosynthesis. Control of the pathway takes place by feedback repression and inhibition by haem of delta-aminolaevulinic-acid synthase. It is suggested that insituations where the activity of this enzyme is derepressed, prophobilinogen deaminase represents a secondary control step.
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PMID:Enzyme abnormalities in the porphyrias. 7 7

Clostridiopeptidase B (EC 3.4.22.8) was not inhibited by stoichiometric amounts of lima bean trypsin inhibitor, ovomucoid trypsin inhibitor, Kuntiz bovine trypsin inhibotor, Kunitz soybean trypsin inhibitor or ovoinhibitor. Activity was diminished at relatively high concentrations of the three latter inhibitors. Human plasma alpha 2-macroglobulin inhibited both the amidase and protease activity of the enzyme. Rat and dog plasmas contained high molecular weight inhibitors, presumably macroglobulins as well. Inhibition by this component was greater in rat plasma than in dog plasma, which may be related to the observation that clostridiopeptidase B-induced generation of kinin activity is indirect in the former plasma, but direct in the later. Leupeptin (N-acetyl-L-leucyl-L-leucyl-L-argininal) and antipain ([S)-1-carboxy-2-phenylethyl] carbamoyl-L-arginyl-L-valyl-L-argininal) inhibited clostridiopeptidase B (Ki of 2 . 10(-8) and 3 . 10(-8) M, respectively). They were potent inhibitors of clostridiopeptidase B-induced kinin release in dog plasma.
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PMID:Clostridiopeptidase B inhibition by plasma marcroglobulins and microbial antiproteases. 8 Feb 31

Formamidase from rat liver proved to be microheterogenous. After preparative isoelectric focusing in density gradient columns, two peaks of formamidase with identical substrate specificity were identified. By analytical focusing in thin layers of polyacrylamide or Sephadex G-75 SF, even five bands could be separated. Their isoelectric points were 4.75, 4.78, 4.82, 4.92 (main band) and 5.11, but their Michaelis constants did not differ significantly (54 to 62 mumol/l). An identical molecular weight of 34700 +/- 3200 for all bands was determined by disc electrophoresis. This value was confirmed by sedimentation analyses (so20,w = 3.00 S) and electrophoresis in the presence of sodium dodecyl-sulfate (Mr 34900 +/- 2300), which only gave a single band. The homogeneity was also confirmed by electrophoresis in the presence of 6M urea. Repeated disc electrophoresis of focusing under native conditions with single, isolated formamidases again resulted in different bands which were identified, not only by Coomassie Blue, but also by their hydrolytic cleavage of naphthyl acetate. Formamidase showed neither proteolytic nor asparagine-amidohydrolase activity and oligosaccharide conjugates were not detectable. Ampholytes, buffer ions, pH and peroxodisulfate did not affect the heterogeneity. "Initial burst" measurements with diethyl(4-nitrophenyl) phosphate yielded an equivalent weight of 36,300. Formylkynurenine reduced this inhibition very effectively. Thus, an extraordinary reactive serine residue appeared to be located in the catalytic site of formamidase. A participation of sulfhydrylgroups in the inactivating reaction of arsenite was excluded although two such groups were detected by 5,5'-dithiobis(2-nitrobenzoic acid). N-Bromosuccinimide reacted primarily with one of the nine tryptophan residues without loss of enzymatic activity, but a 18.6-fold excess of this reagent resulted in a complete loss of activity. The reaction rates of the most effective inhibitors and of the protective action of formylkynurenine were determined. Thus, formamidase must clearly be distinguished from typical serine esterases and proteases.
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PMID:[Formamidase--microheterogeneity, catalytic properties and inhibitors (author's transl)]. 8 81

The rate-limiting step in the degradation of adenine nucleotides in the liver is the conversion of adenosine monophosphate (A.M.P.) to inosine monophosphate by A.M.P. deaminase, which is normally 95% inhibited. When the inhibition is released, uric acid is formed in large excess, and the biosynthesis of purines is increased. We therefore propose that congenital hyperuricaemia is caused by the presence of an abnormal A.M.P. deaminase, which is less sensitive to its physiological inhibitors. Verification of the hypothesis depends upon the availability of liver tissue from patients with congenital hyperuricaemia for kinetic analysis of A.M.P. deaminase. A call for collaboration is addressed to the medical community.
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PMID:Enzyme defect in primary gout. 8 69

Obvious protection of the catalytic activity of Esch. coli L-asparaginase by alpha 2-macroglobulin (alpha 2M) was observed under conditions otherwise propitious to the dissociation of the tetrameric molecule into inactive subunits, i.e. very diluted enzyme solutions or the presence of either SDS or urea. The degree of protection depended on enzyme and alpha 2M concentrations respectively, and on the preincubation time of the alpha 2M-enzyme mixture prior to substrate addition. The formation of a catalytically active complex between alpha 2M and L-asparaginase was confirmed by gel filtration on a Sephadex-G column and by polyacrylamide gel electrophoresis. The fact that the migration distance of the active complex corresponded to the migration of alpha 2M and the absence in that case of a migration band corresponding to the intact molecule suggest that complexing of the enzyme with alpha 2M prevented its dissociation into subunits and thus its inactivation. Addition of alpha 2M to the already dissociated enzyme molecule did not restore its catalytic activity. Alpha2-macroglobulin was shown to have an inhibiting effect on the proteolytic activity of almost all proteases and no effect on their esterolytic activity. Furthermore, it prevents the inhibition of esterolytic activity by some natural compounds. The effect of alpha 2M on other types of catalytic activity has not been investigated enough to afford a generalization of the possible role of this macroglobulin in the control of enzyme activity in the body. This paper reports the results of an in vitro study of the effect of alpha 2M on the catalytic activity of an important amidase, i.e. L-asparaginase (L-asparagine amidohydrolase 3.5.1.1), which in recent years has been used in the treatment of acute lymphocytic leukemia in children.
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PMID:Interaction of alpha 2-macroglobulin with L-asparaginase. 9 Mar 34

Adenosine and the adenine nucleotides have a potent depressant action on cerebral cortical neurons, including identified corticospinal cells. Other purine and pyrimidine nucleotides were either weakly depressant (inosine and guanosine derivatives) or largely inactive (xanthine, cytidine, thymidine, uridine derivatives). The 5'-triphosphates and to a lesser extent the 5'-diphosphates of all the purine and pyrimidines tested had excitant actions on cortical neurons. Adenosine transport blockers and deaminase inhibitors depressed the firing of cortical neurons and potentiated the depressant actions of adenosine and the adenine nucleotides. Methylxanthines (theophylline, caffeine, and isobutylmethylxanthine) antagonized the depressant effects of adenosine and the adenine nucleotides and enhanced the spontaneous firing rate of cerebral cortical neurons. Intracellular recordings showed that adenosine 5'-monophosphate hyperpolarizes cerebral cortical neurons and suppresses spontaneous and evoked excitatory postsynaptic potentials in the absence of any pronounced alterations in membrane resistance or of the threshold for action potential generation. It is suggested that adenosine depresses spontaneous and evoked activity by inhibiting the release of transmitter from presynaptic nerve terminals. Furthermore, the depressant effects of potentiators and excitant effects of antagonists of adenosine on neuronal firing are consistent with the hypothesis that cortical neurons are subject to control by endogenously released purines.
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PMID:Effects of adenosine and adenine nucleotides on synaptic transmission in the cerebral cortex. 9 18

The acylase activity was studied with 65 cultures of mycophilic fungi belonging to 56 species and 33 genera. Among these: 9 species displayed the acylase activity toward ampicillin; 8 species, toward phenoxymethylpenicillin; 6 species, toward benzylpenicillin; and 21 species manifested the complex activity. Many of the active species belonged to the bionecrotrophic group of mycophilic fungi, the number of necrotrophic fungi was less, while that of biotrophs and saprotrophs was even lower.
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PMID:[Acylase activity of mycophilic fungi]. 9 1

Mutants of Pseudomonas aeruginosa were isolated that were acetamide-negative in growth phenotype at 41 degrees C and constitutive for amidase synthesis at 28 degrees C. Two mutants were derived from the magno-constitutive amidase mutant PAC111 (C11), and a third from a mutant that had enhanced inducibility by formamide, PAC153 (F6). The three temperature-sensitive mutants produced amidases with the same thermal stabilities as the wild-type enzyme. Cultures growing exponentially at 28 degrees C, synthesizing amidase constitutively, ceased amidase synthesis almost immediately on transfer to 41 degrees C. Cultures growing at 41 degrees C were transferred to 28 degrees C and had a lag of about 0.5 of a generation before amidase synthesis became detectable. Pulse-heating for 10 min at 45 degrees C of a culture growing exponentially at 28 degrees C resulted in a lag of about 0.5 of a generation before amidase synthesis recommenced after returning to 28 degrees C. Acetamide-negative mutants that were unable to synthesize amidase at any growth temperature were isolated from an inducible strain producing the mutant B amidase PAC398 (IB10). Two mutants were examined that gave revertants producing B amidase but with novel regulatory phenotypes. It is suggested that amidase synthesis is regulated by positive control exerted by gene amiR.
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PMID:Positive regulation of amidase synthesis in Pseudomonas aeruginosa. 9 16

The specific activities of enzymes participating in AMP-catabolizing reactions in promastigotes of Leishmania tropica were determined. The following sequence of reactions is suggested: AMP leads to adenosine leads to adenine leads to hypoxanthine. The initial enzyme of this sequence, AMP nucleotidase, is apparently membrane-bound. The significance of AMP catabolism with respect to adenylate energy charge and a signal transfering mechanism is discussed. Adenine deaminase has been partially purified and characterized. Several purine analogues, inter alia allopurinol, proved to be inhibitors of the adenine deaminase catalyzed reaction.
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PMID:Catabolism of adenosine 5'-monophosphate in promastigotes of Leishmania tropica. 10 64

Hydroxyurea inhibited growth of Pseudomonas aeruginosa strain AI 3 on media containing either acetanilide (N-phenyl acetamide) or acetamide as sole carbon sources. Mutants resistant to hydroxyurea inhibition of growth on acetanilide (OUCH strains) and acetamide (AmOUCH strains) displayed altered growth properties on various amide media compared with the parent strain AI3. AI3 amidase, which catalyses the initial step in the metabolism of acetanilide and acetamide, was inhibited by hydroxyurea in a time-dependent reaction that was slowly reversible at pH 7.2. Compared with AI3 amidase, amidases from the OUCH mutants were much less sensitive to inhibition by hydroxyurea and showed altered substrate specificities and pH/activity profiles; amidases from the AmOUCH mutants were more sensitive to hydroxyurea inhibition but showed increased activity towards acetamide. Association of resistance to hydroxyurea inhibition with a mutation in the amidase structural gene of strain OUCH 4 was confirmed by transduction.
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PMID:Relationship between mutant amidases of Pseudomonas aeruginosa and hydroxyurea as an inhibitor. 10 40


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