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)

The classical Bowman-Birk soybean proteinase inhibitor was modified by hydroxyethylstarch. The modified inhibitor retained the capacity for simultaneous binding of trypsin and human leukocyte elastase. The inhibition constants, Ki, of bovine trypsin, alpha-chymotrypsin and human leukocyte elastase (HLE) increased not more than 10-, 1.5-, and 20-fold, respectively, on modification of the inhibitor. The less effective inhibition is presumably due to the steric hindrance brought about by the conjugation with polysaccharide molecules. The results obtained indicate the pronounced structure differences of the binding regions for trypsin and chymotrypsin/leukocyte elastase in the modified preparation.
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PMID:Conjugation of the Bowman-Birk soybean proteinase inhibitor with hydroxyethylstarch. 917 Feb 52

Serine proteinase inhibitors (serpins) are classically regulators of extracellular proteolysis, however, recent evidence suggests that some function intracellularly. Such "ovalbumin" serpins include the human proteinase inhibitors 6 (PI-6), 8 (PI-8), and 9 (PI-9), plasminogen activator inhibitor 2, and the monocyte/neutrophil elastase inhibitor. PI-9 is a potent granzyme B (graB) inhibitor that has an unusual P1 Glu and is present primarily in lymphocytes. In a search for the murine equivalent of PI-9 we screened cDNA libraries, and performed reverse transcriptase-polymerase chain reaction on RNA isolated from leukocyte cell lines and from lymph nodes and spleens of allo-immunized mice. We identified 10 new ovalbumin serpin sequences: two resemble PI-8, two resemble PI-9, and the remaining six have no obvious human counterparts. By RNA analysis only one of the two sequences resembling PI-9 (designated SPI6) is present in mouse lymphocytes while the other (a partial clone designated mBM2A) is predominantly in testis. SPI6 comprises a 1.8-kilobase cDNA encoding a 374-amino acid polypeptide that is 68% identical to PI-9. mBM2A is 65% identical to PI-9 and over 80% identical to SPI6. Although the reactive loops of SPI6 and mBM2A differ from PI-9, both contain a Glu in a region likely to contain the P1-P1' bond. SPI6 produced in vitro using a coupled transcription/translation system formed an SDS-stable complex with human graB and did not interact with trypsin, chymotrypsin, leukocyte elastase, pancreatic elastase, thrombin, or cathepsin G. Recombinant SPI6 produced in a yeast expression system was used to examine the interaction with human graB in more detail. The second-order rate constant for the interaction was estimated as 8 x 10(4) M-1 s-1, and inhibition depended on the Glu in the SPI6 reactive center. The SPI6 gene was mapped to the same region on mouse chromosome 13 as Spi3, which encodes the murine homolog of PI-6. We conclude that even though their reactive centers are not highly conserved, SPI6 is a functional homolog of PI-9, and that the regulation of graB in the mouse may involve a second serpin encoded by mBM2A. Our identification of multiple sequence homologs of PI-8 and PI-9, and six new ovalbumin serpins, is consonant with the idea that the larger set of granule and other proteinases known to exist in the mouse (compared with human) is balanced by a larger array of serpins.
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PMID:A new family of 10 murine ovalbumin serpins includes two homologs of proteinase inhibitor 8 and two homologs of the granzyme B inhibitor (proteinase inhibitor 9). 918 75

YM-47141, a peptidic compound recently isolated from Flexibactor sp. Q17897, strongly inhibited human leukocyte elastase (HLE) with Ki value 2.1 x 10(-7) M. Unlike other serine protease inhibitors, YM-47141 exhibited relatively weak effects on cathepsin G and alpha-chymotrypsin and its inhibitory Ki values were 9.2 x 10(-4) M and 1.3 x 10(-6) M, respectively. It had little, or no inhibitory effect on plasmin, thrombin, trypsin and kallikrein (IC50 > 10(-4) M). The inhibition of HLE by YM-47141 was reversible and of a mixed type.
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PMID:Effect of YM-47141, a new inhibitor produced by Flexibactor sp. Q17897, on elastase. 920 94

We describe the use of an HPLC/MS technique for the characterization of nicked fragments of hCG beta-subunit. After reductive alkylation of the nicked hCG beta-subunit with vinylpyridine, endoproteinase Glu-C or trypsin was used to digest the protein to produce peptides that could be analyzed by HPLC/electrospray ionization MS. Human leukocyte elastase digestion was used to produce an experimentally nicked hCG. Two nicking sites were observed, between amino acids 42Thr and 43Arg and between 44Val and 45Leu. The former site has not been previously reported for elastase digestion. The structures of the fragments were confirmed by HPLC/MS after removal of the oligosaccharide by direct mass measurement and by mass determination of their proteolytic digests. Without the glycopeptidase treatment, the microheterogeneity of the two N-linked oligosaccharides could be deduced from the spectra of the proteolytic fragments. Nicking with elastase was found to alter the oligosaccharide structures. Nicked beta-subunit samples isolated from the urine of choriocarcinoma patients were also analyzed and the location of the nicking site(s) agreed with that determined by classical techniques. Important differences in the oligosaccharide structures were also observed in these samples, including the presence of triantennary oligosaccharides not found in hCG from healthy subjects. These findings demonstrate the potential of HPLC/MS for characterization of glycoprotein standard preparations.
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PMID:Mass spectrometric characterization of nicked fragments of the beta-subunit of human chorionic gonadotropin. 921 53

Diphenyl 1-(N-peptidylamino)alkanephosphonate esters are highly reactive, specific, and aqueously stable irreversible inhibitors which can be used to probe the functions of many serine proteases, including the lymphocyte granzymes. We synthesized 16 peptide phosphonates with Ala, Met, Phe, or Val P1 amino acid residues, including two biotinylated derivatives for future functional and biochemical characterization of granzymes. The reactivity of the inhibitors was characterized with human leukocyte elastase (HLE), porcine pancreatic elastase (PPE), bovine chymotrypsin, and the granzymes of natural killer (NK) cells, which include a number of proteolytic activities (Asp-ase, Met-ase, etc.) that cleave peptide substrates with these residues in the P1 position. The reactivity and specificity of the phosphonates depended on the length and sequence of the peptidyl moiety and on the leaving group. Z-Ala-Ala-AlaP(OPh)2 was a good inhibitor of HLE and PPE (k(obsd)/[I] = 38 and 30 M(-1) s(-1), respectively) and had little reactivity with chymotrypsin. Z-Phe-Pro-Phe-P(OPh)2 was a good inhibitor of chymotrypsin (k(obsd)/[I] = 17,000 M(-1) s(-1)) and had little reactivity with the elastases. The leaving group of Z-MetP(OPh-4-Cl)2 made it a more effective chymotrypsin inhibitor than Z-MetP(OPh)2 (k(obsd)/[I] values of 142 and 30 M(-1) s(-1), respectively). With granzymes, the compounds reacted with a fraction of the Met-ase, chymase, and Ser-ase activities and lacked reactivity with Asp-ase and tryptase. Z-MetP(OPh-4-Cl)2 was an excellent inhibitor of Met-ase 1. Bi-Aca-Aca-Phe-Leu-PheP(OPh)2 appears to react specifically with one chymase while leaving other chymases untouched. Perforin-dependent lysis mediated by cytotoxic lymphocyte granules was inactivated by Z-Ala-Ala-AlaP(OPh)2, Z-MetP(OPh-4-Cl)2, Z-Leu-PheP(OPh)2, and Bi-Aca-Aca-Phe-Leu-PheP(OPh)2. The biochemical properties and biological efficacy of these inhibitors make them suitable for cellular and physiological studies of granzyme function.
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PMID:Synthesis and kinetic studies of diphenyl 1-(N-peptidylamino)alkanephosphonate esters and their biotinylated derivatives as inhibitors of serine proteases and probes for lymphocyte granzymes. 926 39

Heparan sulfate is rapidly degraded by an endoglycosidase (heparanase) secreted by activated platelets. Since the cleavage and release of heparan sulfate would profoundly alter the local physiology of the endothelium, platelet heparanase activity should be tightly regulated. Consistent with this hypothesis, platelet heparanase was found to degrade endothelial cell heparan sulfate at pH 6.0 but not at pH 7.4, even though 25% of maximum activity was detected at pH 7.4. Loss of heparanase activity occurred rapidly (t1/2 is approximately equal to 20 min) and reversibly at physiologic pH but did not occur at acidic pH (<7.0). Inactivation of heparanase at pH 7.4 did not affect heparin binding and was reversed by 0.5 M NaCl or by heparan sulfate but not by chondroitin sulfate, suggesting inactive heparanase could be tethered on cell surfaces and the function regulated by heparan sulfate. Heparanase was gradually inactivated by trypsin and urokinase (t1/2 = 5 h) but resisted cleavage by leukocyte cathepsin G, leukocyte elastase, plasmin, and thrombin. These findings are consistent with a model in which platelet heparanase is active at the low pH of inflammation but inactive under physiologic conditions preventing inadvertent cleavage of heparan sulfate and loss of physiologic functions of endothelial cells.
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PMID:Regulation of platelet heparanase during inflammation: role of pH and proteinases. 957 70

The effect of modification of basic pancreatic trypsin inhibitor (BPTI) by derivatives of fatty acids (oleic, stearic) on the inhibition of bovine trypsin and human leukocyte elastase (HLE) was studied. Kinetic constants of interaction with trypsin and inhibition constants of both enzymes were determined. Hydrophobization of BPTI had virtually no effect on its high affinity for trypsin. The coupling of cis-unsaturated oleoyl radicals to the inhibitor molecule significantly increased the efficiency of HLE inhibition, whereas the coupling of saturated stearoyl radicals completely canceled the anti-elastase activity and in some cases promoted the substrate hydrolysis.
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PMID:Effect of hydrophobization of basic pancreatic proteinase inhibitor on the inhibition of bovine trypsin and human leukocyte elastase. 986 42

In acute pancreatitis, particularly in severe cases, polymorphonuclear neutrophil (PMN) elastase induces tissue damage in remote organs such as the lung, as well in the pancreas itself. Therefore, we examined the therapeutic effect of a specific synthetic inhibitor of PMN elastase (ONO-5046: Ono Pharmaceuticals, Osaka, Japan) on the lung, liver, and kidney, as well as pancreas, in severe hemorrhagic pancreatitis in dogs. Acute hemorrhagic pancreatitis was induced by the injection of a mixture of autologous bile and porcine trypsin into the main pancreatic duct. Lipopolysaccharide (LPS) was administered intravenously as a septic challenge. Two animal groups were used. In one group, continuous infusion of ONO-5046 was started prior to the injection of LPS (ONO group). In the other group (control), saline was infused instead. At the end of the experiment (330 min after the injection of bile and trypsin), the pancreas revealed severe hemorrhagic pancreatitis, and a large amount of bloody ascites had accumulated in the peritoneal cavity. The white blood cell count was markedly reduced in response to the induction of pancreatitis, and was decreased further by the septic attack, irrespective of the administration of ONO-5046, although the count increased again in the ONO group. Serum levels of amylase and alpha2-macroglobulin-trypsin complex increased similarly in both groups following administration of bile and trypsin. Serum Ca levels decreased in both groups. At the end of the experiment, the wet weight of the lung was slightly higher in the control group (without ONO-5046). Microscopically, the pancreas showed severe hemorrhage accompanied by extensive interstitial edema in both groups. The lung and liver demonstrated mild infiltration of inflammatory cells in the interstitium in both groups, although the inflammatory change in the liver was slightly milder in the ONO group. These findings indicate that severe hemorrhagic pancreatitis cannot be alleviated by the administration of a specific inhibitor of PMN elastase alone, although this may lessen damage to remote organs such as the liver and lung. The white blood cell count decreased markedly after the induction of acute pancreatitis, and much more after a septic challenge. This seems to be closely related to the accumulation of bloody ascites in the peritoneal cavity.
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PMID:Effect of a specific synthetic inhibitor of neutrophil elastase (ONO-5046) on the course of acute hemorrhagic pancreatitis in dogs. 993 92

We investigated the regulation of arachidonic acid liberation catalyzed by group-IV cytosolic phospholipase A2 (cPLA2) in human platelets upon stimulation with thrombin through interaction with protease-activated receptor-1 (PAR-1) or glycoprotein Ib. Leupeptin, a protease inhibitor, completely inhibited thrombin-induced arachidonic acid liberation and Ca2+ mobilization, with inhibition of its protease activity. However, preincubation with thrombin in the presence of leupeptin potentiated Ca2+ ionophore-induced arachidonic acid liberation. The preincubation did not affect the intracellular Ca2+ level or cPLA2 activity in response to ionomycin. Human leukocyte elastase, which cleaves glycoprotein Ib, did not inhibit the enhancement of arachidonic acid liberation by thrombin in the presence of leupeptin. However, the effect of thrombin with leupeptin was abolished by a peptide corresponding to residues 54-65 of hirudin (hirudin peptide), which impairs the binding of thrombin to PAR-1. Furthermore, Phe-Pro-Arg chloromethyl ketone (PPACK)-thrombin, which binds to platelets but has no protease activity, also enhanced Ca2+ ionophore-induced arachidonic acid liberation. In contrast, trypsin with leupeptin did not mimic the effect of thrombin with leupeptin, and furthermore trypsin-induced arachidonic acid liberation was insensitive to hirudin peptide. On the basis of the present results, we suggest that thrombin may accelerate cPLA2-catalyzed arachidonic acid liberation through non-proteolytic action toward PAR-1 but not toward glycoprotein Ib in co-operation with the proteolytic action leading to Ca2+ mobilization.
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PMID:Acceleration of Ca2+ ionophore-induced arachidonic acid liberation by thrombin without the proteolytic action toward the receptor in human platelets. 1009 48

The effect of modifications of Met, Arg, and Lys residues on the inhibitory activity of a serine proteinase-inhibiting 21-kD protein from potato tubers has been studied. The data indicate that the 21-kD protein has two independent reactive sites for human leukocyte elastase (or chymotrypsin) and trypsin. It is concluded that the 21-kD inhibitor has Met and Arg residues in the P1 position of the reactive sites responsible for interactions with elastase (or chymotrypsin) and trypsin. It is shown that the 21-kD protein is capable of forming a triple complex binding simultaneously one molecule of trypsin and one molecule of chymotrypsin.
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PMID:Reactive sites of the 21-kD protein inhibitor of serine proteinases from potato tubers. 1052 25


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