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 syntheses are described of p-guanidino-L-phenylalanine and some of its derivatives. alpha-N-(p-Toluenesulphonyl)-p-guanidino-L-phenylalanine methyl ester is an excellent substrate of bovine trypsin (EC 3.4.21.4) (Km 57 micron; kcat. 320s-1 at pH 7.4-8.0) and a very poor substrate of human thrombin (EC 3.4.21.5) (Km 190 micron, kcat. 0.2s-1) and bovine chymotrypsin (EC 3.4.21.1). The ester inhibits thrombin clotting activity. It also inhibits the amidase and esterase activities of human thrombin, this inhibition being of the mixed type. The inhibition constant, K1, of the order of 1 micron, increases with increasing inhibitor concentration. This suggests that the enzyme binds the inhibitor at multiple sites. The importance of the residue at the P1 position [notation of Berger & Schechter (1970) Philos. Trans. R. Soc. London Ser. B 257, 249-264] in determining the selectivity of a substrate or quasi-substrate among trypsin-like enzymes is borne out. p-Guanidino-L-phenylalanine may have a use in the synthesis of selective peptide inhibitors of thrombin.
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PMID:The interaction of alpha-N-(p-toluenesulphonyl)-p-guanidino-L-phenylalanine methyl ester with thrombin and trypsin. 62 42

An enzyme deacylating preferentially N-acyl-L-aromatic amino acids was partially purified from rat kidney. The purification procedure included DEAE-cellulose column chromatography, (NH4)2SO4 fractionation, gel-filtration on a Sephadex G-200 column and further DEAE-cellulose chromatography. The enzyme was thus separated from aminoacylase (N-acylamino-acid amidohydrolase, EC 3.5.1.14) (acylase I). Although the enzyme preparation contained other acylases, the experimental data (effect of p-chloromercuric benzoate, heat stability and inhibition between substrates) suggest that the enzyme acts preferentially on N-acyl derivatives of L-tryptophan, L-tyrosine, L-phenylalanine and L-histidine. This enzyme appears to be present in many animal tissues.
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PMID:N-Acyl-L-aromatic amino acid deacylase in animal tissues. 62 89

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

1. Two chymotrypsins, called chymotrypsin I and II, were purified from the pyloric caeca of rainbow trout, by (NH4)2SO4 fractionation, hydrophobic interaction chromatography (phenyl-Sepharose) and ion-exchange chromatography (DEAE-Sepharose). 2. The approximate molecular weights of chymotrypsin I and II were 28,200 (+/- 1200) and 28,800 (+/- 900), respectively, as determined by SDS-PAGE and their isoelectric points were about 5. 3. The pH optima of the enzymes were centered around nine, when assayed for succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide (Suc-AAPF-NA) as substrate and both enzymes were unstable at pH values below 5. 4. The amidase activity of both enzymes increased with temperature up to about 55 degrees C. Chymotrypsin I was found to be more heat stable than chymotrypsin II, an effect most likely explained by stronger calcium binding of the former. 5. The trout chymotrypsins were significantly more active than bovine alpha-chymotrypsin when assayed against Suc-AAPF-NA at 25 degrees C and casein at low temperatures (10-20 degrees C), indicating an adaptation of the activities of the trout chymotrypsins to the habitation temperatures of the fish.
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PMID:Purification and characterization of two chymotrypsin-like proteases from the pyloric caeca of rainbow trout (Oncorhynchus mykiss). 149 72

Activity of tissue and blood plasma kallikreins as well as total content of their inactive precursors were studied in rabbit eye structures and media: iris, ciliary body, cornea, vascular striatum, retina, aqueous humor, tear liquid, lacrimal gland by means of fluorimetric procedure using Z-Phe-Arg-MCA as a substrate. Dissimilar capacity of the trypsin soya bean inhibitor and of aprotinin (basic inhibitor of Kunitz type) to inhibit tissue and blood plasma kallikreins enabled to differentiate the enzymatic activity. Lacrimal gland contained the highest activity of tissue kallikrein which amounted to 70% of total Z-Phe-Arg-MCA-hydrolyzing activity of the homogenate. Total Z-Phe-Arg-MCA-amidase activity and activity of individual kallikreins was distinctly lower in all the eye structures and media studied as compared with that of lacrimal gland. Activity of tissue kallikrein was higher than blood serum kallikrein activity in iris, ciliary body, vascular striatum, retina and conjunctiva. The highest content of prekallikreins was found in conjunctiva, aqueous humor, iris and ciliary body. Tissue and blood plasma kallikrein-kinin systems appear to carry out dissimilar functions in eye tissue structures; they are apparently involved in pathogenesis of some eye diseases.
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PMID:[Activity of tissue and plasma kallikrein and level of their precursors in eye tissue structures and media of healthy rabbits]. 172 76

Lipoproteins (d = 1.05-1.12 g/ml) were obtained from pooled serum by density gradient ultracentrifugation and used as a source for isolation of apolipoprotein (a) (apo(a]. It was found that both these lipoproteins and purified apo(a) possess negligible amidolytic and proteolytic activity. After preincubation of lipoproteins and apo(a) with collagen-Sepharose, the increase in enzymatic activity was observed. The activation of purified apo(a) also occurred upon its storage in the cold. After two week storage at 7 degrees C, the amidase activity, as measured by splitting of the substrate D-Pro-Phe-Arg-pNA, was increased from 0.009 U/mg to 0.85 U/mg. The amidase activity was completely inhibited by phenylmethylsulfonyl fluoride (10(-3) M) and by soybean trypsin inhibitor (10(-5) M); it was not inhibited by aprotinin (10(-6) M). Activated apo(a) did not split azocasein but converted plasma prekallikrein to kallikrein and degraded apolipoprotein B-100.
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PMID:Enzymatic properties of active form of human apolipoprotein (a). 240 48

Human pancreatic kallikrein (H. Panc. K.) was purified from human pancreas by serial liquid chromatographies. The final preparation had a specific activity of 9.2 AU/A280 (AU: amidase unit for H-Pro-Phe-Arg-MCA) and its N-terminal sequence coincided with the reported sequence determined from cloned cDNA analysis. In HPLC (gel filtration), one symmetrical peak corresponding to a molecular weight of 48,000 was obtained. In SDS-PAGE without 2-mercaptoethanol, one band corresponding to a molecular weight of 52,000 was obtained. Protease inhibitor specificities of H. Panc. K. were the same as those of human urinary kallikrein (HUK) and hog pancreatic kallikrein (hog Panc. K.), while anti-HUK rabbit antibody inhibited the activities of H. Panc. K. and HUK, but not that of hog Panc. K. From the analysis of affinity for concanavalin A and erythroagglutinating phytohemagglutinin, the carbohydrate parts of H. Panc. K. are relatively rich in bi-(or multi-) antennary complex type sugar chains with bisecting GlcNAc compared with those of human salivary kallikrein and HUK. These findings will be a help to clarify the physiological and pathophysiological roles of H. Panc. K. in the pancreas and pancreatic diseases, especially in acute pancreatitis.
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PMID:[Purification of human pancreatic kallikrein and organ-specificities of human glandular kallikreins]. 260 Nov 18

Human pancreatic kallikrein (H.Panc.K.) was purified from human pancreas by ion exchange chromatography on DEAE-cellulose, affinity chromatographies on p-aminobenzamidine Sepharose 6B and aprotinin aminocellulofine, followed by gel filtration on Sephacryl S-200. The final preparation had a specific activity of 9.2 AU/A280 (AU; amidase unit for H-Pro-Phe-Arg-MCA) and its N-terminal sequence coincided with the reported sequence for H.Panc.K.. In HPLC (gel filtration), one symmetrical peak corresponding to a molecular weight of 48,000 was obtained. In SDS-PAGE without 2-mercaptoethanol (2-ME), one band corresponding to a molecular weight of 52,000 was obtained, but with 2-ME, 2 bands, 52,000 and 30,000, were obtained. Km value for MCA was 4.9 x 10(-2) mM. Proteinase inhibitor specificities of H.Panc.K. were the same as those of human urinary kallikrein (HUK) and hog pancreatic kallikrein (hog Panc.K.), while anti-HUK antibody inhibited the activities of H.Panc.K. and HUK, but not that of hog Panc.K.. From the analysis of affinity for concanavalin A (Con A) and erythroagglutinating phytohemagglutinin (E-PHA), the carbohydrate parts of H.Panc.K. are relatively rich in biantennary complex type sugar chains with bisecting GlcNAc compared with those of human salivary kallikrein (H.Saliv.K.) and HUK.
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PMID:Characterization of human pancreatic kallikrein. 261 57

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


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