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:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A technique utilizing Pregnant Mare's Serum Gonadotropin and Human Chorionic Gonadotropin treatment of hens (Gallus domesticus), followed by manual ovulation of the excised follicles, was developed to obtain a large number of mature ova. The intact ova were used to test whether acrosin, partially purified from the spermatozoa of the cock (Gallus domesticus), partially purified rabbit testicular acrosin and commercial preparations of several hydrolytic enzymes could dissolve the inner vitelline membrane. Enzymes were applied to pieces of filter paper placed on the ovum. Cock acrosin and endopeptidases such as trypsin, chymotrypsin, collagenase and elastase hydrolyzed the membrane whereas exopeptidases such as leucine aminopeptidase and carboxypeptidase A did not. Phospholipase A, sulfatase, hyaluronidase, beta-glucuronidase and rabbit testicular acrosin also failed to hydrolyze the membrane. Cock acrosin hydrolysis of the ovum surface was inhibited by soybean trypsin inhibitor. The surface of the ovum over the germinal disc region was hydrolyzed more quickly by cock acrosin than the surface over other regions of the ovum. Acrosin from cock sperm caused the release of trichloroacetic acid soluble material absorbing at 280 nm from sonicated preparations of inner vitelline membranes. Hydrolysis was greatest at pH 8.0 and was inhibited by soybean trypsin inhibitor.
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PMID:Hydrolysis of the hen egg vitelline membrane by cock sperm acrosin and other enzymes. 0 Apr 54

Two proteinases (2A and 2B) purified from the granular fraction of horse blood leucocytes degrade casein (Km values 12.8 and 6mg/ml respectively) with maximum activity at pH 7.4 and in the presence of 2m-urea. Urea-denatured haemoglobin, fibrinogen, albumin and resorcin/fuchsin-stained elastin are digested at a slower rate. The enzymes hydrolyse synthetic substrates of elastase, N-benzyloxycarbonyl-L-alanine 4-nitrophenyl ester (Km 0.114 and 0.178 mM) and N-acetyl-tri-L-alanine methyl ester (Km 5.55 and 0.98 mM), but they do not hydrolyse synthetic substrates of trypsin, chymotrypsin and thrombin. The examined proteinases are completely inhibited by 2 mM-di-isopropyl phosphorfluoridate and show a sensitivity to butyl and octyl isocyanates similar to that of pancreatic elastase. The pH-dependence of their photoinactivation in the presence of Rose Bengal indicates the presence of histidine in the active centre. Proteinase 2A rather insensitive to iodination by IC1 as is pancreatic elastase, whereas proteinase 2B is totally inactivated after incorporation of five iodine atoms per enzyme molecule.
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PMID:Substrate specificity and modifications of the active centre of elastase-like neutral proteinases from horse blood leucocytes. 0 9

An electrophoretically homogeneous trypsin-like proteinase, two homogeneous proteases (presumably metal-containing) and two elastases, possessing the ATEE-esterase activity, were isolated from protofradin, a protease preparation from Actinomyces fradiae 119, using fractionation on KM-cellulose K-32. The trypsin like proteinase of protofradin possesses the esterase activity, equal to the activity of pancreatic trypsin. Protofradin elastases differ in their pH optima, response to EDTA, stability upon storage and the degree of elastin hydrolysis. The specificity of elastase is probably the same, since in elastin both enzymes hydrolyze the peptide bonds, formed by the NH2-group of glycine and alanine residues, found in elastin in large amounts. The end products of elastin hydrolysis are tripeptides.
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PMID:[Isolation of individual proteases from protofradin]. 1 37

Cobalamin (Cbl; vitamin B(12)) malabsorption in pancreatic insufficiency can be partially corrected by bicarbonate and completely corrected by pancreatic proteases but the mechanisms involved are unknown. Because saliva contains enough R-type Cbl-binding protein (R protein) to bind all of the dietary and biliary Cbl, it is possible that R protein acts as an inhibitor of Cbl absorption and that pancreatic proteases are required to alter R protein and prevent such inhibition. To test this hypothesis we studied the ability of R protein and intrinsic factor (IF) to compete for Cbl binding and ability of pancreatic proteases to alter this competition. Human salivary R protein bound Cbl with affinities that were 50- and 3-fold higher than those of human IF at pH 2 and 8, respectively. Cbl bound to IF was transferred to an equal amount of R protein with t((1/2))'s of 2 and 90 min at pH 2 and 8, respectively, and within several hours respective ratios of R protein-Cbl/IF-Cbl of 50 and 2 were observed. Cbl bound to R protein was not transferred to IF at either pH 2 or 8. Incubation of R protein with pancreatic proteases at pH 8 led to a 150-fold decrease in its affinity for Cbl. Incubation of R protein-Cbl with pancreatic proteases led to complete transfer of Cbl to IF within 10 min. Gel filtration studies with R protein-[(57)Co]Cbl and (125)I-R protein showed that pancreatic proteases partially degraded R protein. Pancreatic proteases differed in their ability to effect these changes with trypsin > chymotrypsin > elastase. Pancreatic proteases did not alter IF in any of the parameters mentioned above. Pepsin failed to alter either R protein or IF. THESE STUDIES SUGGEST THE FOLLOWING: (a) that Cbl is bound almost exclusively to R protein in the acid milieu of the stomach, rather than to IF as has been assumed previously; (b) that Cbl remains bound to R protein in the slightly alkaline environment of the intestine until pancreatic proteases partially degrade R protein and enable Cbl to become bound exclusively to IF; and (c) that the primary defect in Cbl absorption in pancreatic insufficiency is a lack of pancreatic proteases and a failure to alter R protein and effect the transfer of Cbl to IF. These studies also suggest that the partial correction of Cbl malabsorption observed with bicarbonate is due to neutralization of gastric HCl, since at slightly alkaline, pH IF can partially compete with R protein for the initial binding and retention of Cbl.
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PMID:Effect of proteolytic enzymes on the binding of cobalamin to R protein and intrinsic factor. In vitro evidence that a failure to partially degrade R protein is responsible for cobalamin malabsorption in pancreatic insufficiency. 2 56

At pH 5.5, sodium trifluoroacetate is a potent competitive inhibitor of porcine elastase (Ki = 2.6 mM) and human leukocyte elastase (Ki = 9.3 mM). For both enzymes the Ki increases strongly with pH. Sodium fluoride is inactive on pancreatic elastase and sodium acetate is a weak inhibitor of this enzyme. Trifluoroethanol inhibits both enzymes but is less active than trifluoroacetate in acidic pH conditions. Bovine trypsin and alpha-chymotrypsin are resistant to the action of sodium trifluoroacetate and trifluoroethanol. The interaction between sodium trifluoroacetate and pancreatic elastase is also demonstrated by 19F NMR spectroscopy. Trifluoroacetyltrialanine is able to displace trifluoroacetate from its complex with pancreatic elastase. In addition, a method using turkey ovomucoid for the active site titration of leukocyte and pancreatic elastase is described.
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PMID:NMR and enzymatic investigation of the interaction between elastase and sodium trifluoroacetate. 2 76

During the process of cultivation of Th. vulgaris several proteases are formed. In the present investigation the extensively purified major component was used. The substrate specificity was determined by means of 7 proteins, 7 amino acid esters, 5 fatty acid esters and 15 amino acid 4-nitroanilides. Among the protein substrates tested, urea denaturated hemoglobin was split best, followed by gelatin, casein, field bean protein, serum albumin and gluten. The weakest rate of hydrolysis was observed with elastin. In contrast to this acetyl-(L-ala)3-methylester, that is a substrate for elastase, was split best from all the esters tested. Only 8% of this activity could be found with the chymotrypsin substrates acetyl-L-tyr-ethylester and acetyl-L-phe-ethylester and 1% of the above activity with the trypsin substrates tosyl-L-arg-methylester and benzoyl-L-arg-methylester. The fatty acid esters and the p-nitroanilides were hydrolyzed much more slowly. The pH-optimum of thermitase was found in the weakly alkaline region of pH 7 to 9. There were only small differences between the individual high and low molecular substrates. The temperature optimum was between 60 and 75 degrees C for esters and p-nitroanilides as substrates and at 90 degrees C for casein. It should be mentioned that the enzyme was quickly inactivated at temperatures above 70 degrees C.
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PMID:[Characterization of a protease from Thermoactinomyces vulgaris (thermitase). 3. Substrate specificity and properties of partially purified thermitase]. 3 57

Guanylate cyclase activity (GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2.), measured in purified rat liver plasma membranes, was markedly increased by treatment with various purified proteases. The effect was maximal with trypsin, alpha-chymotrypsin, papain, and thermolysin (6- to 8-fold increase with 5 to 20 microgram of protease/ml) and lower with subtilisin and elastase (3- to 4-fold increase). The activation was due to an increase in the maximal velocity of the cyclizing reaction. No modification was observed either in the apparent affinity for the substrate MnGTP or in the cooperative behavior of the enzyme kinetics which displayed Hill coefficients of 1.6 for both basal and activated states. The Triton X-100-dispersed guanylate cyclase remained sensitive to papain, which suggests that the action of proteases was not restricted to an indirect action upon the membranous environment of the guanylate cyclase. In contrast, the cytosolic soluble guanylate cyclase, assayed in the presence or absence of sodium azide, was absolutely insensitive to papain. Thus, proteolysis represents a previously undescribed mechanism for activating membranous guanylate cyclase systems, which might be of importance in the physiological regulation of this enzyme.
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PMID:Activation of rat liver guanylate cyclase by proteolysis. 3 29

Highly sensitive gelatin substrate films prepared according to a recent variant of the procedure are studied for their susceptibility to the action of various endopeptidases and exopeptidases. Trypsin, papain, elastase, and chymotrypsin are found to hydrolyze the gelatin films most easily, while higher enzyme concentrations are required in case of pepsin, plasmin and collagenase. The exopeptidases, i.e. leucine aminopeptidase, amino acid arylamidase and carboxypeptidases A and B do not cause lysis of gelatin substrate films. The example of a rabbit blastocyst protease involved in implantation is given to demonstrate the application of gelatin substrate film tests for studies of enzymes which have no or little activity against known synthetic substrates (like BANA or GPNA) but hydrolyze gelatin films. Studies of interactions of this blastocyst protease with various inhibitors of known specificity, however, show that the active center of this enzyme nevertheless has striking similarities to trypsin (and also to chymotrypsin). The enzyme is possibly related to elastase. It is emphasized that, besides this, there are a number of different protease type enzymes in rabbit blastocyst and uterine tissues, some of which can be demonstrated only with chromogenic substrates and some only by gelatin methods. Aspects of applicability of the two types of protease tests are briefly discussed.
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PMID:[The specificity and sensitivity of the gelatin base protease substrate film test ]. 4 23

Pancreatitis was induced by injection of autologous bile into the main pancreatic duct of dogs. An initial fall in blood pressure was accompanied by appearance of large quantities of active trypsin, chymotrypsin, and elastase in pancreatic exudate with full saturation of protease inhibitors. The enzymes soon appeared in ascitic fluid and lymph, but only in the form of complexes with alpha1-antitrypsin, and alpha2-macroglobulin. No such complexes were detected in venous blood indicating short half-life in the circulation. These studies confirm the release of pancreatic enzymes during bile-induced pancreatitis, and quantify an important protective role for plasma protease inhibitors in this situation.
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PMID:Release of proteolytic enzymes in bile-induced pancreatitis in dogs. 5 Sep 58

Human leukocytes, when exposed to aggregated human gamma-globulin (AHGG) or immune complexes (isolated from RA synovial fluid) fixed to a cartilagenous surface, release neutral proteases that degrade the extracellular matrix of cartilage. The chondromucoprotein destruction by these proteases is suppressed by a variety of synovial fluids but is not susceptible to inhibition by trypsin, chymotrypsin, elastase inhibitors, or a combination of these agents. The inhibitory effect of synovial fluid can be reversed in the presence of increasing enzyme concentrations. Intact viable human polymorphonuclear leukocytes in the presence of AHGG also release a collagenase precursor that can be activated by limited proteolysis with trypsin or RA synovial fluids. Enzyme release (neutral proteases) by phagocytosing cells is inhibited by the antiinflammatory agents phenylbutazone and colchicine; these agents do not affect release of the collagenase precursor. However, the latent collagenase release is susceptible to inhibition when leukocytes are preincubated (prior to exposure to AHGG) with inhibitors of protein synthesis. Under these conditions, neutral protease release is unaffected.
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PMID:Connective tissue-degrading enzymes of human leukocytes. 5 2


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