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)

The substrate specificity of carboxypeptidase (F-II) purified from watermelon for various synthetic peptides and esters was examined kinetically. The enzyme showed a broad substrate specificity against various carbobenzoxy- and benzyl-dipeptides. Peptides containing glycine or proline were hydrolyzed slowly by the enzyme. Peptides containing hydrophobic amino acids were hydrolyzed rapidly. The presence of hydrophobic amino acid residues, not only at the C-terminal position but also at the second position and probably the third position from the C-terminal resulted in an increase in the rate of hydrolysis. Inhibition studies with diisopropyl flurophosphate and diastereomers of carbobenzoxy-Phe-Ala demonstrated that the peptidase and esterase activities of the enzyme are both catalyzed by the same site of the enzyme molecule, but the binding sites for peptides and esters seem not to be the same. The enzyme also had amidase activity, which was optimal at pH 7.0.
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PMID:Substrate specificity of carboxypeptidase from Watermelon. 0 3

Two DFP-sensitive alkaline proteinases with strong esterase activity toward Ac-(Ala)3-OMe, designated as alkaline serine proteinases D and E, were purified pronase, a protease mixture from St. griseus K-1. Each was shown to be homogeneous by acrylamide disc gel electrophoresis. The molecular weights of these enzymes were estimated to be about 27,000 be gel filtration. Studies on their actions on acyl-tl-amino acid methyl or ethyl esters indicated that proteinases D and E both exhibited a broad substrate specificity and hydrolyzed the ester bonds of esters containing Trp, Tyr, Phe, Leu, and Ala. The esterase activities of both enzymes toward Ac-(Ala)3-OMe were the highest among proteinases so far isolated from various sources. Proteinases D and E also lacked cystine residues in their molecules, being entirely different from alkaline serine proteinases A, B, and C in pronase. Some differences were , however, observed between them as regards pH stability, behavior on CM-cellulose, mobility on polyacrylamide electrophoresis, and amidase activity toward Suc-(Ala)3-pNA.
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PMID:Alkaline serine proteinases D and E of Streptomyces griseus K-1. 1 70

A family of mutant amidases has been derived by experimental evolution of the aliphatic amidase of Pseudomonas aeruginosa strain PAC1. Mutation amiE16, in the structural gene for the enzyme, results in the production of the mutant B amidase by strain B6. This strain, unlike the wild-type, can utilize butyramide for growth. Strain B6 gave rise by a single mutational event to strain V9, utilizing valeramide, and strain PhB3, utilizing phenylacetamide. Strain V9 was not itself able to utilize phenylacetamide but gave rise by mutation to the phenylacetamide-utilizing mutant PhV1. Peptide 108 was isolated from chymotryptic digests of mutant amidases from strains B6, PhB3 and PhV1, but could not be detected in chymotryptic digests of the wild-type amidase. The sequence of peptide 108 was established as Met-Arg-His-Gly-Asp-Ile-Phe. Thermolytic digests of mutant amidases from strains B6, PhB3, PhV1 and V9 were compared with digests of the wild-type amidase. A peptide of the composition Met, Arg, His, Gly2, Asp3, Ile, Ser3, Thr, Val was found in the digest of the wild-type amidase and was replaced in the digests of the mutant amidases by a peptide of the composition Met, Arg, His, Gly2, Asp3, Ile, Ser3, Thr, Val, Phe. Mutation amiE16 is common to the four mutant enzymes and can be accounted for by the mutation Ser leads to Phe. The sequence of the chymotryptic peptide corresponds with the N-terminal sequence of the amidase protein, and can also be related to the thermolysin peptides. It is concluded that mutation amiE16 is a Ser leads to Phe change at position 7 from the N-terminus and the effect of this on the enzyme conformation is discussed.
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PMID:Molecular basis of altered enzyme specificities in a family of mutant amidases from Pseudomonas aeruginosa. 11 34

Amino acid analysis on the acid hydrolyzate of polymyxin S1 revealed its amino acid composition. Isolation of the constituent amino acids and measurement of their optical activities clarified their chiralities: Dab(5L), Thr(3L), Ser(1D) and Phe(1D). The constituent fatty acid was identified with anteisononanoic acid by gas chromatography and mass spectrometry. By the action of polymyxin acylase, deacyl polymyxin S was obtained. Successive EDMAN degradation reaction on deacyl polymyxin S revealed the amino acid sequence. Further evidence for the structure of polymyxin S1 was obtained by partial acid hydrolysis on tetra-(DNP)-polymyxin S1.
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PMID:The structure of polymyxin S. (Studies on antibiotics from the genus Bacillus. XXI). 20 83

Amino acid analysis of the acid hydrolyzate of polymyxin T1 revealed the amino acid composition. Isolation of the constituent amino acids and measurement of their optical activities clarified their chiralities. These were 2,4-diaminobutyric acid (6L), Thr(1L), Leu(2L) and Phe(1D). The constituent fatty acid was identified as anteisononanoic acid by gas chromatography and mass spectrometry. Deacylation with polymyxin acylase afforded deacyl polymyxin T. Successive EDMAN degradation on deacyl polymyxin T revealed most of its amino acid sequence. The chemical cleavage reaction for fragmentation of threonyl peptide amino acid sequence. The chemical cleavage reaction for fragmentation of threonyl peptide on penta(DNP)-polymyxin T1 cleaved it at the C-terminal side of the Thr residue to afford a DNP-octapeptide, whose sequence was clarified by EDMAN degradation. Thus, the structure of polymyxin T1 was determined.
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PMID:The structure of polymyxin T1. (Studies on antibiotics from the genus Bacillus. XXII). 20 84

The uptake of L-4-azaleucine was examined in Escherichia coli K-12 strains to determine the systems that serve for its accumulation. L-4=Azaleucine in radio-labeled form was synthesized and resolved by the action of hog kidney N-acylamino-acid amidohydrolase (EC 3.5.1.B) on the racemic alpha-N-acetyl derivative of DL-[dimethyl-14C]4-azaleucine. L-4-Azaleucine is taken up in E. coli by energy-dependent processes that are sensitive to changes in the pH and to inhibition by leucine and the aromatic amino acids. Although a single set of kinetic parameters was obtained by kinetic experiments, other evidence indicates that transport systems for both the aromatic and the branched-chain amino acids serve for azaleucine. Azaleucine uptake in strain EO317, with a mutation leading to derepression and constitutive expression of branched-chain amino acid (LIV) transport and binding proteins, was not repressed by growth with leucine as it was in parental strain EO300. Lesions in the aromatic amino acid transport system, aroP, also led to changes in the regulation of azaleucine uptake activity when cells were grown on phenylalanine. Experiments on the specificity of azaleucine uptake and exchange experiments with leucine and phenylalanine support the hypothesis that both LIV and aroP systems transport azaleucine. The ability of external azaleucine to exchange rapidly with intracellular leucine may be an important contributor to azaleucine toxicity. We conclude from these and other studies that at least four other process may affect azaleucine sensitivity: the level of branched-chain amino acid biosynthetic enzymes; the level of leucine, isoleucine, and valine transport systems; the level of the aromatic amino acid, aroP, uptake system; and, possibly, the ability of the cell to racemize D and L amino acids. The relative importance of these processes in azaleucine sensitivity under various conditions is not known precisely.
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PMID:Transport of L-4-azaleucine in Escherichia coli. 23 51

The possibility to keep some biochemical reactions of the parent strains (urease-positive, glucose fermentation, phenylalanine-deaminase-positive, H2S but not indol production) was demonstrated in 5 L-forms, obtained from as many strains of Pr. mirabilis and in 1 L-form, isolated from a vaginal secretion and identified as belonging to the same species. The indirect hemagglutination technique, made by the sonicated antigen in 3 of the 6 L-forms with Proteus OXK antiserum, resulted positive in titers varying from 1:128 to 1:1024. Crossed tests made with antisera for different bacterial species (e. coli, Shigella, klebsiella, ecc.) and of Mycoplasma (M. hominis, M. orale, M. salivarium, M. fermentans, M. arthritidis) put in evidence aspecific reactions only in 1.3% of the bacterial antisera. On the contrary, all 5 antisera for Mycoplasma were able to agglutinate the sensitized erythrocytes at titers quite analogous to that of the homologous antiserum. The sensitivities to various antibiotics of the 6 L-forms and the parent strains has been determined. All of L-forms were more resistent to the tetracycline than L-forms of other bacterial species. On the basis of te results got by biochemical and serological tests, we confirm the necessity to make use of both the groups of tests, in order to identify the L-forms of recent isolation.
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PMID:[Researches on some biochemical and serological properties and on the sensitivity to antibiotics of L-forms of "Proteus" (author's transl)]. 40 87

Genito-urethral specimens from 3260 women and 1170 men, with ailments suggestive of gonorrhoea, were examined for growth of oxidase positive rodshaped bacteria, as well as of gonococci. Moraxella osloensis was identified in 26 cases (0.64 per cent of women and 0.43 per cent of men). Three patients harboured phenylalanine negative (or weakly reacting) and tryptophan deaminase negative M. phenylpyrouvica and, in three cases, a Flavobacterium species was detected. Among six oropharyngeal specimens from patients suspected of gonorrhoea, two yielded growth of oxidase positive rods, Kingella kingae and Neisseria elongata, respectively, N. gonorrhoeae was isolated from 537 patients, i.e., 12.1 per cent of all cases. The isolates of oxidase positive rods were in most cases completely identified by streptomycin resistance transformation. On this basis, the diagnostic reliability of some morphological and cultural-biochemical tests and gas chromatography was examined. Gas chromatographic analysis of fatty acid and alcohol composition of whole cells proved distinctive of species defined genetically, irrespective of confusing behaviour of some strains in other tests.
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PMID:Oxidase positive rods from cases of suspected gonorrhoea. A comparison of conventional, gas chromatographic and genetic methods of identification. 40 88

Two molecular forms of cobalt-activated acylase present in human tissues and one or three in sera of patients with viral hepatitis were noted. They have different substrate specificity. Only form 2 is strongly inhibited by alpha-hydroxyisocaproyl-tyrosine and -phenylalanine. Electrophoretic migrations of all enzyme forms are different from those of aminoacylase. Immunoglobulin antiform 2 of the acylase does not precipitate other forms of cobalt-activated acylase or aminoacylase.
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PMID:Molecular forms of cobalt-activated acylase in human tissues and serum of patients with viral hepatitis. 44 40

Protein C is a vitamin K-dependent protein, which exists in bovine plasma as a precursor of a serine protease. In this study, protein C was isolated to homogeneity from human plasma by barium citrate adsorption and elution, ammonium sulfate fractionation, DEAE-Sephadex chromatography, dextran sulfate agarose chromatography, and preparative polyacrylamide gel electrophoresis. Human protein C (M(r) = 62,000) contains 23% carbohydrate and is composed of a light chain (M(r) = 21,000) and a heavy chain (M(r) = 41,000) held together by a disulfide bond(s). The light chain has an amino-terminal sequence of Ala-Asn-Ser-Phe-Leu- and the heavy chain has an aminoterminal sequence of Asp-Pro-Glu-Asp-Gln. The residues that are identical to bovine protein C are underlined. Incubation of human protein C with human alpha-thrombin at an enzyme to substrate weight ratio of 1:50 resulted in the formation of activated protein C, an enzyme with serine amidase activity. In the activation reaction, the apparent molecular weight of the heavy chain decreased from 41,000 to 40,000 as determined by gel electrophoresis in the presence of sodium dodecyl sulfate. No apparent change in the molecular weight of the light chain was observed in the activation process. The heavy chain of human activated protein C also contains the active-site serine residue as evidenced by its ability to react with radiolabeled diisopropyl fluorophosphate. Human activated protein C markedly prolongs the kaolin-cephalin clotting time of human plasma, but not that of bovine plasma. The amidolytic and anticoagulant activities of human activated protein C were completely obviated by prior incubation of the enzyme with diisopropyl fluorophosphate. These results indicate that human protein C, like its bovine counterpart, exists in plasma as a zymogen and is converted to a serine protease by limited proteolysis with attendant anticoagulant activity.
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PMID:Human plasma protein C: isolation, characterization, and mechanism of activation by alpha-thrombin. 46 91


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