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)

Factor XII was assayed in acetone-treated and kaolin-activated human citrated plasma (total plasma dilution 1.0 + 0.3 v/v during activation with kaolin, 1.8 mg/ml incubate). Measurements were performed with the tetrapeptide Bz-Ile-Glu-Gly-Arg-pNa (S-2222) and with prekallikrein as substrates. The correlation of both methods to another S-2222 based method recently described was good, r = 0.90 and 0.85 for the two methods respectively. Under the assay conditions used, FXIIa was present as a S-2222 amidase that could be blocked by corn inhibitor, whereas plasma kallikrein was found to be present partly as an amidase blocked by a low concentration of soybean trypsin inhibitor, and partly in a functional state not inhibited and adding to the measured level of FXII. The presence of benzamidine 0.7 to 2.1 mM during acetone treatment increased the measured level of FXII assayed both as prekallikrein activator and as S-2222 amidase.
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PMID:Assay of factor XII in human plasma using prekallikrein or the chromogenic peptide S-2222 as substrates--significance of the functional state of plasma kallikrein. 278 41

Human hepatoma (Hep G2) cells secrete nanogram quantities of carboxypeptidase enzymes which are capable of hydrolyzing COOH-terminal lysine and arginine residues. A carboxypeptidase with a neutral pH optimum (greater than pH 7.0) was partially purified from the conditioned medium and compared with pure plasma carboxypeptidase N. The two enzymes behaved in a similar manner on gel filtration (apparent Mr = 280,000), DE52 ion exchange chromatography, and concanavalin A-affinity chromatography and were indistinguishable enzymatically and immunologically. Immunoblots of the Hep G2 and plasma carboxypeptidase N before and following deglycosylation with peptide-N4-[N-acetyl-beta-glucosaminyl]asparagine amidase F revealed a similar, if not identical, multimeric structure. A second carboxypeptidase with a lower molecular weight and a pH optimum of 5.0 was also detected in the Hep G2 medium.
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PMID:Characterization of the carboxypeptidase N secreted by Hep G2 cells. 284 69

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

Two subsequent phases of hepatogenic encephalopathy (HE), the metabolic and precomatous phase, were produced in rats by thioacetamide treatment. Plasma and brain levels of arginine and its metabolites in the arginine-glutamate pathway, and activities of 2 brain enzymes of this pathway: arginase (L-arginine amidohydrolase, EC3521) and ornithine amino-transferase (OAT, ornithine-oxo-acid aminotransferase, EC26113) were measured in these rats. Plasma arginine sharply decreased in the metabolic phase and rose above control level in the precomatous phase, whereas ornithine and glutamate increased and urea decreased in both phases. Brain amino acids levels remained unchanged throughout, confirming earlier report of their insensitivity to external manipulation. Both brain enzymes showed a similar stepwise increase in their activities up to 150% the control level. The results are indicative of increased involvement of arginine as a precursor of amino acid neurotransmitters glutamate and GABA, with possible implication for the course of HE.
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PMID:Arginine in thioacetamide-induced hepatogenic encephalopathy in rats: activation of enzymes of arginine metabolism to glutamate. 287 5

An assay for sperm-bound amidase activity was validated using bovine spermatozoa and N-benzoyl-DL-arginine p-nitroanilide as substrate. The assay had intra- and interassay coefficients of variations of 5 and 12%, respectively. It is an inexpensive, simple and rapid assay since 100 samples can be evaluated in 2 hours and it requires only 4 X 10(6) spermatozoa per sample. Sperm-bound amidase activity was proportional (r = 0.95) to the percentage of spermatozoa with an intact acrosome, as determined by differential interference-contrast microscopy. A change of five percentage units in the incidence of damaged spermatozoa was detectable. Using this procedure, assessment of sperm-bound amidase activity is therefore a sensitive and efficient means of evaluating acrosomal integrity.
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PMID:Sperm-bound amidase activity as a marker for acrosomal integrity in bull spermatozoa. 303 14

The detrimental effects of excessive Ni on plant growth have been well known for many years. More recent evidence indicates that Ni is required in small amounts for normal plant growth and development. Ni is an essential component of urease in plants and microorganisms. A deficiency of Ni in plants is reported to result in necrotic lesions in leaves in response to toxic accumulations of urea. Urease plays an essential role in mobilization of nitrogenous compounds in plants, a process that is especially important during seed germination and fruit formation when protein reserves are degraded into amino acids. Arginine, an abundant amino acid in plants, when degraded produces urea as a product and urease is needed for urea utilization. Theories of urea formation during allantoin degradation in Glycine max have been recently refuted. In G. max ureides apparently are metabolized via an amidohydrolase reaction with subsequent degradation of ureidoglycine, yielding glyoxylate, NH+4 and CO2. No evidence is available for the formation of urea in this pathway. Nitrogen-fixing symbionts, such as Rhizobium and Bradyrhizobium, contain two known Ni enzymes: urease and hydrogenase. Optimum growth of nodulated legumes and actinorhizal plants may depend on an adequate supply of Ni to meet the requirements of the Ni-requiring enzymes in host plants and endophytes. The seeds of severely Ni-deficient Hordeum are completely inviable, thus providing conclusive evidence for the essentiality of Ni for this species. The evidence indicates that Ni must be added to the list of micronutrient elements generally required by plants.
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PMID:Nickel as a micronutrient element for plants. 307 27

To localize the binding region of porcine tissue-type plasminogen activator (EC 3.4.21.31) (t-plasminogen activator) to heparin, functionally active A and B chains (molecular mass of each 33 kDa) were separated from the two-chain t-plasminogen activator after mild reduction and alkylation. The A chain bound to fibrin-Sepharose, but not to heparin-Sepharose. In contrast, the B chain showed amidase activity toward HD-Ile-Pro-Arg-p-nitroanilide (S-2288) and a high affinity for heparin-Sepharose, but no affinity for fibrin-Sepharose. Plasminogen activator activity of the B chain was stimulated by heparin (about 3-fold), but not by fibrin. On the other hand, the elastase digestion fragments of plasminogen, kringle 1-3 and kringle 4, had no affinity for a heparin-Sepharose column, whereas the other fragment, Val442-plasminogen, efficiently bound to the column and was eluted with 1.6 M KSCN-containing buffer. The stimulatory effect of fibrin on two-chain t-plasminogen activator-catalyzed Val442-plasminogen activation was clearly diminished by heparin. These results suggest that heparin can form a complex with both t-plasminogen activator and plasminogen molecules through their catalytic regions located in each B chain, and that the heparin connection between t-plasminogen activator and plasminogen may improve the plasminogen activation kinetics by making a situation in which t-plasminogen activator is easily approachable to plasminogen.
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PMID:Localization of the binding sites of porcine tissue-type plasminogen activator and plasminogen to heparin. 312 Jul 75

A covalent conjugate between the plasminogen activator urokinase and polyclonal rabbit anti-human fibrinogen has been formed using the heterobifunctional coupling reagent N-succinimidyl 3-(2-pyridyldithio) propionate. The resultant urokinase-anti-human fibrinogen conjugate was separated from unreacted material by gel filtration. The conjugate exhibited amidase activity against the small chromogenic substrate pyroglutamyl-glycyl-arginine-p-nitroanilide as well as plasminogen activator activity in an assay employing plasminogen and the plasmin substrate D-valyl-leucyl-lysine-p-nitroanilide. Retention of antibody specificity for fibrinogen was demonstrated using an enzyme linked immunoassay procedure. The conjugate was found to have greater stability in human plasma than unconjugated urokinase.
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PMID:Plasminogen activator-anti-human fibrinogen conjugate. 316 1

The toxic and biological activities of four samples of Trimeresurus purpureomaculatus venom were examined. The lethality, protein composition and biological activities of the four venom samples were similar. Three of the venom samples had LD50 (i.v.) values of 0.9 micrograms/g while the fourth had a lower LD50 (i.v.) of 0.45 micrograms/g. All four venom samples exhibited hemorrhagic, edema-inducing, anticoagulant and thrombin-like activities as well as the usual enzymes found in crotalid venoms. DEAE-Sephacel ion exchange chromatographic fractionation of the venom yielded 10 protein fractions. Only two fractions (fractions A and F) were lethal to mice; the major lethal fraction being fraction F. This fraction had an LD50 (i.v.) of 0.2 micrograms/g and exhibited hemorrhagic, edema-inducing and thrombin-like activity. It also exhibited phospholipase A, arginine ester hydrolase, arginine amidase, protease, 5'-nucleotidase, acetylcholinesterase and alkaline phosphomonoesterase activities. The lethal potency of fraction F is potentiated by fraction G, which exhibited anticoagulant activity as well as hemorrhagic, edema-inducing and enzymatic activities. Fractions F plus G account for almost 100% of the lethal potency of the venom.
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PMID:Biological properties of Trimeresurus purpureomaculatus (shore pit viper) venom and its fractions. 324 58

Human plasma alpha-1-antiproteinase interacted with porcine trypsin in two different manners. One was a well known interaction, which resulted in inhibition of the proteolytic activity of the trypsin. The other has not been described to date, and resulted in retention of the amidolytic activity of the trypsin towards benzoyl-L-arginine p-nitroanilide in the presence of soybean trypsin inhibitor. The latter, so-called trypsin-protein amidase, activity is essentially the same as that observed with vertebrate alpha-macroglobulin and rodent murinoglobulin under similar conditions. All attempts to separate the two different activities as well as to abolish either activity by means of chemical or physical modifications were unsuccessful. The proteolysis-inhibiting interaction, which was virtually completed within 5 min, was predominant over the amidolysis-retaining interaction, when the inhibitor/trypsin molar ratio was less than 1. On the other hand, the amidolysis-retaining interaction, which proceeded much more slowly, became evident when the molar ratio was greater than 1.
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PMID:Amidolytic activity of porcine trypsin bound to human plasma alpha-1-antiproteinase. 325 75


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