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)

Seven arginylfluoroalkanes ('arginine fluoroalkyl ketones') were synthesized by using a modified Dakin-West procedure. The structure of benzoyl-Arg-CF2CF3 was analysed by 19F-n.m.r. spectroscopy and m.s. and the compound was shown to exist primarily as a hydrate or cyclic carbinolamine. Arginylfluoroalkanes are good inhibitors of blood-coagulation serine proteinases and were found to be slow-binding inhibitors for bovine trypsin with Ki values of 0.2-56 microM. Benzoyl-Arg-CF2CF3 was the best inhibitor for bovine thrombin and human Factor XIa, and inhibited thrombin and Factor XIa competitively with Ki values of 13 microM and 62 microM respectively. The best inhibitor for pig pancreatic kallikrein was p-toluoyl-Arg-CF3, with a Ki value of 35 microM. Benzoyl-Arg-CF3 and benzoyl-Arg-CF2CF3 inhibited human plasma kallikrein competitively, with Ki values of 50 microM. None of the seven arginylfluoroalkanes was a good inhibitor of human factor Xa or of Factor XIIa. The arginylfluoroalkanes were tested in the prothrombin time (PT) and activated partial thromboplastin time (APTT) coagulant assays. Two fluoroketones, benzoyl-Arg-CF2CF3 and 1-naphthoyl-Arg-CF3, had significant anticoagulant activity. Benzoyl-Arg-CF2CF3 was found to prolong the PT 1.8-fold at 120 microM and to prolong the APTT 2.4-fold at 90 microM, whereas 1-naphthoyl-Arg-CF3 only prolonged the APTT 1.7-fold at 100 microM.
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PMID:The synthesis of arginylfluoroalkanes, their inhibition of trypsin and blood-coagulation serine proteinases and their anticoagulant activity. 230 84

A T-kininogenase has been purified to homogeneity from rat submandibular gland extracts by DEAE-Sepharose chromatography and preparative gel electrophoresis. The purified protein has an apparent Mr of 28,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and splits into heavy and light chains with Mr of 22,000 and 6,000 in the presence of dithiothreitol. It is an acidic glycoprotein with pI of 4.65-4.75. The carbohydrate moiety is located on the light chain and binds concanavalin A and wheat germ agglutinin. The active site serine residue of the heavy chain is labeled with [14C]diisopropylfluorophosphate and visualized by fluorography. NH2-terminal amino acid sequences of the light and heavy chains reveal 74-84% identity to rat tissue kallikrein, tonin, and other kallikrein-related enzymes. The enzyme cleaves T-kininogen to release T-kinin which was separated by high performance liquid chromatography on a reverse phase C18 column and identified by a kinin radioimmunoassay. Its T-kininogenase but not N-tosyl-L-arginine methyl ester esterase activity can be enhanced 10-fold in the presence of dithiothreitol. The esterolytic activity of the enzyme is inhibited by soybean trypsin inhibitor, aprotinin, leupeptin, and antipain; whereas lima bean and ovomucoid trypsin inhibitors stimulate its activity. The enzyme is localized at the granular convoluted tubule and striated duct cells in rat submandibular glands by immunohistochemistry. The results indicate that T-kininogenase belongs to the group of structurally similar yet distinct kallikrein-like serine proteases.
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PMID:Purification and characterization of a kallikrein-like T-kininogenase. 230 30

The amino acid sequence of protease inhibitor II, previously isolated from bovine spleen, has been completely elucidated and reveals a high homology (approximately 90%) with that of bovine pancreatic trypsin inhibitor (BPTI), the well-known Kunitz inhibitor. The secondary and tertiary structure of this new inhibitor appears similar to that of BPTI. Whereas its affinity for bovine trypsin, chymotrypsin, and trypsinogen is almost identical to that of BPTI, the affinity for porcine pancreatic kallikrein is decreased, as expected on the basis of the amino acid substitutions. Analysis of the pH dependence of the affinity constant confirms the previous assignment of the ionizable groups, whose pK values are perturbed on complex formation, to kallikrein and not to the inhibitor molecule.
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PMID:Primary structure and antiproteolytic activity of a Kunitz-type inhibitor from bovine spleen. 241 11

It was confirmed that esterolytic activity was significantly elevated in plasma of patients with acute pancreatitis, which correlated better with the stage of the disease than serum amylase level. Using the several column chromatography procedures, pancreatic kallikrein, trypsin and pancreatic elastase were separated and purified from alpha 2-macroglobulin (alpha 2-M) fractions of patients plasma with acute pancreatitis. From this this result, it was confirmed that kallikrein was liberated into the blood stream from the pancreas during attacks of acute pancreatitis and the liberated kallikrein combined with alpha 2-M. Furthermore, the coexistence of trypsin is required for the complex formation of alpha 2-M and pancreatic kallikrein. It was speculated that alpha 2-M might be decomposed by the excessive amount of elastase, and consequently, might release all of its combining enzymes into the blood stream. In the present study, the activation mechanism of fibrinolytic enzyme system in plasma by human pancreatic elastase was investigated. Elastase not only converted the co-existing plasminogen to low molecular weight plasminogen which could be easily activated by the activators, but also inhibited alpha 2-M and alpha 2-plasmin inhibitor, and consequently, induced the activation of the fibrinolytic enzyme system in plasma. Furthermore, it was also confirmed that elastase could activate plasma kallikreinogen to kallikrein.
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PMID:[Interaction of proteases and their inhibitors in the pathogenesis of pancreatitis]. 241 45

Treatment of aprotinin with Raney nickel in the presence or absence of denaturants yielded [Ala2 14,38]aprotinin. Aprotinin and [Ala2 14,38]aprotinin were separated by ion exchange chromatography at pH 8 using CM-Sepharose, fast flow. [Ala2 14,38]aprotinin is a proteinase inhibitor, but it possesses lower affinities than aprotinin, for the enzymes trypsin, alpha-chymotrypsin, pancreatic kallikrein and plasmin as reflected by higher Ki values [Ala2 14,38]aprotinin is slowly degraded by trypsin. The optical activity of [Ala2 14,38]aprotinin in different solvents is quite similar to that of aprotinin, or that of its hydrolysis products, [seco-15/16]aprotinin or [di-seco-15/16,39/40]-aprotinin. This is taken as good evidence for analogous molecular conformations of all these substances.
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PMID:[Ala214,38]aprotinin: preparation by partial desulphurization of aprotinin by means of Raney nickel and comparison with other aprotinin derivatives. 243 18

Inhibitory effects of nafamostat mesilate (nafamostat) on various enzymes were investigated, and they were compared with those of gabexate mesilate (gabexate), leupeptin, aprotinin and urinastatin in vitro. Nafamostat inhibited trypsin, plasmin, thrombin, pancreatic kallikrein, Clr and Cls more potently than gabexate and leupeptin. Gabexate and leupeptin did not inhibit pancreatic kallikrein and thrombin, respectively. Aprotinin inhibited trypsin, plasmin, pancreatic kallikrein and chymotrypsin. Urinastatin inhibited trypsin and chymotrypsin. Nafamostat inhibited the complement-mediated hemolysis in diluted serum more potently than gabexate and leupeptin, but aprotinin and urinastatin did not. Nafamostat, furthermore, inhibited the complement-mediated hemolysis in undiluted serum, but gabexate did not. Unlike aprotinin and urinastatin, nafamostat and gabexate inhibited alpha 2-macroglobulin bound trypsin as well as free trypsin to the same extent. The inhibitory effect of gabexate toward trypsin was reduced more markedly than that of nafamostat after incubation with plasma at 37 degrees C. These results show that nafamostat is more useful than other inhibitors such as gabexate, leupeptin, aprotinin and urinastatin.
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PMID:[Comparative studies of nafamostat mesilate and various serine protease inhibitors in vitro]. 243 41

The inhibition of trypsin, human blood plasma kallikrein and porcine pancreatic kallikrein by aprotinin (native and immobilized on carboxymethyl ester of dextran) was investigated. The experimental values of Ki of native and immobilized aprotinin--enzyme complexes are equal to 0.037 and 0.045 nM for trypsin, 0.38 and 112.3 nM for pancreatic kallikrein and 34.4 and 454.5 nM for plasma kallikrein with N alpha-benzoyl-L-arginine ethyl ester as substrate, and to 82.6 and 231.7 nM for plasma kallikrein with a natural substrate--kininogen. These data suggest that covalent binding of aprotinin to the water-soluble polysaccharide carrier does not interfere with its interaction with trypsin, whereas the inhibition of kallikreins decreases, especially that of pancreatic kallikrein. The experimental results indicate the marked differences in the structure of the binding site of the active center (or its environment) of plasma and pancreatic kallikreins, on one hand, and trypsin, on the other, as well as the differences between the plasma and pancreatic kallikreins. A high requirement of kallikreins to the maintenance of the native conformation of aprotinin during immobilization is postulated.
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PMID:[Effect of covalent binding of aprotinin with a polysaccharide carrier on its inhibition of kallikrein from human plasma, porcine pancreatic kallikrein and trypsin]. 243 35

On incubation of [di-seco-15/16,39/40]aprotinin with human plasmin, porcine pancreatic kallikrein or bovine or porcine trypsin in neutral or slightly alkaline solutions [seco-39/40]aprotinin is slowly formed with enzymatic resynthesis of the reactive-site bond 15/16. With chymotrypsin, however, further degradation of [di-seco-15/16,39/40]aprotinin takes place without enzymatic resynthesis. The apparent rate constants for the synthesis of [seco-39/40]aprotinin with kallikrein and trypsin have been determined and indicate that the bond-forming reaction is 10-200-fold slower with [di-seco-15/16,39/40]aprotinin than with [seco-15/16]aprotinin. The newly formed [seco-39/40]aprotinin has similar kinetic constants for the complexation with its cognate enzymes as aprotinin, indicating that any distortion of the secondary binding region due to cleavage of the Arg39-Ala40 bond does not seriously influence binding and affinities.
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PMID:Enzymatic resynthesis of the "reactive site" bond in the modified aprotinin derivatives [seco-15/16]aprotinin and [Di-seco-15/16,39/40]aprotinin. 246 26

The interactions of mouse murinoglobulin and alpha-macroglobulin with several proteinases were investigated by filtration and by assays of amidolytic activity towards synthetic substrates in the presence of proteinaceous enzyme inhibitors as well as assays of the inhibition of proteolytic activity. Mouse alpha-macroglobulin formed complexes with thrombin, clotting factor Xa, plasmin, pancreatic kallikrein, plasma kallikrein, submaxillary gland trypsin-like proteinase, neutrophil elastase, and pancreatic elastase. These complexes lost the proteolytic activities against high-molecular-weight substrates, but protected the active sites of the enzymes from inactivation by their proteinaceous inhibitors. Mouse murinoglobulin showed essentially the same properties except (i) that it did not form a complex with the clotting factor Xa, and (ii) that it did not protect plasma kallikrein, neutrophil elastase or submaxillary proteinase from inactivation by their proteinaceous inhibitors, although it formed complexes with these proteinases. No interaction was detected between Clostridium histolyticum collagenase and murinoglobulin or alpha-macroglobulin. These results indicate (i) that murinoglobulin has a proteinase-binding spectrum similar to that of alpha-macroglobulin, but is weaker in the ability to protect the bound proteinases from inactivation by the proteinaceous inhibitors than alpha-macroglobulin and (ii) that mouse alpha-macroglobulin has essentially the same inhibitory spectrum as the human homologue.
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PMID:Proteinase inhibitory spectrum of mouse murinoglobulin and alpha-macroglobulin. 248 76

Kininogen sequence analogs containing amino acid residues around the Arg-Ser cleavage site of bovine kininogens were prepared with bulky aliphatic residues in P3 position. KKI-7 (containing a cyclohexylacetyl group) and KKI-8 (containing an adamantaneacetyl group) both inhibited human urinary kallikrein (HUK) with Ki of 4 microM. These inhibitors were 40 times more potent than the corresponding peptide containing the naturally occurring Pro at P3 and were one-seventh as susceptible to hydrolysis by HUK. Rat submaxillary kallikrein (RSK) and porcine pancreatic kallikrein (PPK) were also inhibited by these analogs. Both analogs were poor inhibitors of human plasma kallikrein, while their capacity to inhibit bovine trypsin was 1/3 and 1/17, respectively, that to inhibit HUK. In a rat blood flow study, KKI-7 infusion depressed the response to injected RSK. The response gradually returned toward normal 30 to 60 min after the infusion was terminated. Blood flow increase of dog jejunal artery in response to infused PPK was blunted by the simultaneous local infusion of Trasylol, KKI-7, or KKI-8, whereas these infusions did not alter the response to infused bradykinin. The vehicle infusion did not attenuate the response either to PPK or bradykinin. These analogs appear to have greater specificity and stability than those previously developed and to be appropriate for the in vivo inhibition of glandular kallikreins.
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PMID:In vivo inhibition of tissue kallikreins by kininogen sequence analogue peptides. 248 44


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