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)

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

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

alpha-Hydroxyisocaproyltyrosine (HyIc-Tyr-OH), a potent competitive inhibitor of the cobalt-activated acylase form 2, was synthesized. Its derivative, alpha-aminopentyl-HyIc-Tyr-OEt was coupled to cyanogen bromide-activated Sepharose 4B and was used for about 100-fold purification of the acylase from human liver by affinity chromatography. The preparation obtained did not show aminoacylase, aspartyl acylase or alanylarylamidase activities. The same chromatographic method was also applied to isolate form 2 of the serum acylase from patients with viral hepatitis and guinea pig placenta.
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PMID:Purification of cobalt-activated acylase by affinity chromatography. 57 48

Newly synthesized and non-toxic acyl derivatives of p-aminobenzoic acid were used as substrates indiagnostic kit for assay of cobalt-activated acylase activity. The enzyme activity, in serum of patients with viral hepatitis, depends on time, type and treatment of the disease and also on age and sex of patients. The presence of HBs antigen has no influence on it. In the patient sera 1-3 molecular forms of the enzyme were found but in the liver of healthy or sick individuals two forms were noted. Using alpha-hydroxy-isocaproyl-tyrosine covalently coupled to Sepharose 4B as a bioadsorbent; the form 2 of acylase from human liver was isolated and separated from the form 1, aminoacylase and aspartyl acylase. Specific immunoglobulins anti-form 2 does not react with other forms of the enzyme either in serum or in the liver.
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PMID:Cobalt-activated acylase in serum of patients with viral hepatitis. 74 9

Protease I, a periplasmic endopeptidase from Escherichia coli has been further purified by a modified procedure. While the purified protein consists of a single polypeptide chain of about 21000 daltons, its molecular weight in dilute salt solution was estimated to be near 43000, suggesting that the enzyme has a marked tendency to dimerize. It has only one disulphide bond and is very sensitive to urea. In agreement with previous evidence of a chymotrypsin-like specificity, hydrolytic assays of various p-nitrophenyl esters of N-substituted amino acids showed that phenylalanine and tyrosine derivatives are the best substrates for the enzyme. The Km(app) for N-benzoyloxycarbonyl-L-tyrosin-p-nitrophenyl ester at pH 7.5 In 100 mM sodium phosphate buffer at 25 degrees C was found to be 0.2 mM. In contrast to chymotrypsin, protease I is unable to hydrolyse N-acetyl-L-phenylalanine ethyl ester and its tyrosine analogue. Moreover, the enzyme appears devoid of amidase activity and exhibits a low activity upon polypeptides. At 37 degrees C, it cleaves the carboxymethylated B-chain of bovine insulin at four points: Phe25-Tyr26, Phe24-Phe25, Leu15-Tyr16 and Ser9-His10. From a detailed study of peptides bonds hydrolyzed, it was concluded that protease I has a stringent requirement for both residues forming the scissile bond, and appears to possess an extended hydrophobic binding site.
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PMID:Protease I from Escherichia coli. Some physicochemical properties and substrate specificity. 79 43

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

A new D-stereospecific amino acid amidase has been partially purified from Ochrobactrum anthropi SCRC SV3, which had been isolated and selected from soil. The Mr of the enzyme was estimated to be about 38,000, and its isoelectric point was 5.3. The enzyme catalyzes the stereospecific hydrolysis of D-amino acid amide to yield D-amino acid and ammonia. The major substrates included D-phenylalanine amide, D-tyrosine amide, D-tryptophan amide, D-leucine amide, and D-alanine amide.
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PMID:A new D-stereospecific amino acid amidase from Ochrobactrum anthropi. 275 65

The effect of chemical modification on the pseudocholinesterase and aryl acylamidase activities of purified human serum pseudocholinesterase was examined in the absence and presence of butyrylcholine iodide, the substrate of pseudocholinesterase. Modification by 2-hydroxy-5-nitrobenzyl bromide, N-bromosuccinimide, diethylpyrocarbonate and trinitrobenzenesulfonic acid caused a parallel inactivation of both pseudocholinesterase and aryl acylamidase activities that could be prevented by butyrylcholine iodide. With phenylglyoxal and 2,4-pentanedione as modifiers there was a selective activation of pseudocholinesterase alone with no effect on aryl acylamidase. This activation could be prevented by butyrylcholine iodide. N-Ethylmaleimide and p-hydroxy-mercuribenzoate when used for modification did not have any effect on the enzyme activities. The results suggested essential tryptophan, lysine and histidine residues at a common catalytic site for pseudocholinesterase and aryl acylamidase and an arginine residue (or residues) exclusively for pseudocholinesterase. The use of N-acetylimidazole, tetranitromethane and acetic anhydride as modifiers indicated a biphasic change in both pseudocholinesterase and aryl acylamidase activities. At low concentrations of the modifiers a stimulation in activities and at high concentrations an inactivation was observed. Butyrylcholine iodide or propionylcholine chloride selectively protected the inactivation phase without affecting the activation phase. Protection by the substrates at the inactivation phase resulted in not only a reversal of the enzyme inactivation but also an activation. Spectral studies and hydroxylamine treatment showed that tyrosine residues were modified during the activation phase. The results suggested that the modified tyrosine residues responsible for the activation were not involved in the active site of pseudocholinesterase or aryl acylamidase and that they were more amenable for modification in comparison to the residues responsible for inactivation. Two reversible inhibitors of pseudocholinesterase, namely ethopropazine and imipramine, were used as protectors during modification. Unlike the substrate butyrylcholine iodide, these inhibitors could not protect against the inactivation resulting from modification by 2-hydroxy-5-nitrobenzyl bromide, N-bromosuccinimide and trinitrobenzenesulfonic acid. But they could protect against the activation of pseudocholinesterase and aryl acylamidase by low concentrations of N-acetylimidazole and acetic anhydride thereby suggesting that the binding site of these inhibitors involves the non-active-site tyrosine residues.
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PMID:Chemical modification of the bifunctional human serum pseudocholinesterase. Effect on the pseudocholinesterase and aryl acylamidase activities. 286 42

We have identified and isolated two new calcium-activated neutral hydrolases from human ventricular muscles. The one is an esterase, of which molecular weight was 300,000, required millimolar concentration of Ca2+, hydrolyzed Ac-Tyr-OEt X H2O, optiaml pH at 7.0. The other is an amidase, of which molecular weight was 70,000, also required millimolar concentration of Ca2+, hydrolyzed a synthetic substrate for chymotrypsin, Suc-Leu-Leu-Val-Tyr-MCA, with optimal pH at 7.2. Both enzymes did not degrade casein or contractile proteins (myosin, actin, troponin and tropomyosin). Their activities were not inhibited by exogenous protease inhibitors, leupeptin, antipain, monoiodoacetic acid and chymostatin, while the amidase activity was blocked by the endogenous inhibitor against calcium-activated neutral protease (CANP). Thus, their characters are different from chymotrypsin or CANP and they seems to be new hydrolases in the human heart.
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PMID:Identification of two new calcium dependent hydrolases in the human heart. 301 Sep 97

Carboxypeptidase Y hydrolyzed N-substituted peptide-4-methylcoumarin-7-amides (peptide-NH-Mec) at pH 7 by releasing 7-amino-4-methylcoumarin (NH2-Mec) which was then followed by carboxypeptidase action. In particular, a chymotrypsin-directed substrate, Suc-Leu-Leu-Val-Tyr-NH-Mec, was hydrolyzed by the enzyme with a second-order rate constant of 7200 M-1 s-1, which is compatible with the rate for an anilide substrate and some N-substituted dipeptides. The activity was completely inhibited by phenylmethylsulfonyl fluoride and competitively depressed by the presence of an N-substituted dipeptide. Dependences of kinetic parameters on pH were different from those of carboxypeptidase, esterase, amidase, and anilidase activities. Carboxypeptidases P from Penicillium janthinellum and W from wheat also hydrolyzed some of these peptide-NH-Mec derivatives in a similar manner but at a rather low rate. Thus, the NH2-Mec-releasing activity may be considered to be intrinsic to serine carboxypeptidases in general. Taking into consideration this endopeptidase-like activity of serine carboxypeptidases, fluorogenic substrates should be used carefully to specify endopeptidases in crude extracts.
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PMID:Action of serine carboxypeptidases on endopeptidase substrates, peptide-4-methyl-coumaryl-7-amides. 390 5


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