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)

DPC423, 1-[3-(aminomethyl)phenyl]-N-[3-fluoro-2'-(methylsulfonyl)[1,1'-biphenyl]-4-yl]-3-(trifluoromethyl)-1H-pyrazole-5-carboxamide, is a synthetic, orally bioavailable, competitive, and selective inhibitor of human coagulation factor Xa (K(i) [nM]: factor Xa, 0.15; trypsin, 60; thrombin, 6000; plasma kallikrein, 61; activated protein C, 1800; factor IXa, 2200; factor VIIa, >15,000; chymotrypsin, >17,000; urokinase, >19,000; plasmin, >35,000; tissue plasminogen activator, >45,000; complement factor I, 44,000 [IC(50)]). In vitro, DPC423 produced anticoagulant effects in human plasma in which it doubled prothrombin time, activated partial thromboplastin time, and Heptest clotting time at 3.1 +/- 0.4, 3.1 +/- 0.4, and 1.1 +/- 0.5 microM, respectively. In dogs, DPC423 had a good pharmacokinetic profile with an oral bioavailability of 57%, a plasma clearance of 0.24 L/kg/h, and a plasma half-life of 7.5 h. In rabbit and rat models of arteriovenous shunt thrombosis, DPC423 was an effective antithrombotic agent with an IC(50) of 150 and 470 nM, respectively. The antithrombotic effect of DPC423 is likely to be related to the inhibition of factor Xa but not to the inhibition of thrombin or due to direct inhibition of platelet aggregation. Therefore, based on potency, selectivity, efficacy, and oral bioavailability, DPC423 was selected for clinical development as an oral anticoagulant for the potential treatment of thrombotic disorders. Preliminary human data suggest that DPC423 is orally bioavailable in humans and has a long plasma half-life.
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PMID:Nonpeptide factor Xa inhibitors: DPC423, a highly potent and orally bioavailable pyrazole antithrombotic agent. 1217 91

The specific Kunitz Bauhinia ungulata factor Xa inhibitor (BuXI) and the Bauhinia variegata trypsin inhibitor (BvTI) blocked the activity of trypsin, chymotrypsin, plasmin, plasma kallikrein and factor XIIa, and factor Xa inhibition was achieved only by BuXI (K(i) 14 nM). BuXI and BvTI are highly homologous (70%). The major differences are the methionine residues at BuXI reactive site, which are involved in the inhibition, since the oxidized protein no longer inhibits factor Xa but maintains the trypsin inhibition. Quenched fluorescent substrates based on the reactive site sequence of the inhibitors were synthesized and the kinetic parameters of the hydrolysis were determined using factor Xa and trypsin. The catalytic efficiency k(cat)/K(m) 4.3 x 10(7) M(-1)sec(>-1) for Abz-VMIAALPRTMFIQ-EDDnp (lead peptide) hydrolysis by factor Xa was 10(4)-fold higher than that of Boc-Ile-Glu-Gly-Arg-AMC, widely used as factor Xa substrate. Lengthening of the substrate changed its susceptibility to factor Xa hydrolysis. Both methionine residues in the substrate influence the binding to factor Xa. Serine replacement of threonine (P(1)') decreases the catalytic efficiency by four orders of magnitude. Factor Xa did not hydrolyze the substrate containing the reactive site sequence of BvTI, that inhibits trypsin inhibitor but not factor Xa. Abz-VMIAALPRTMFIQ-EDDnp prolonged both the prothrombin time and the activated partial thromboplastin time, and the other modified substrates used in this experiment altered blood-clotting assays.
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PMID:Kinetic characterization of factor Xa binding using a quenched fluorescent substrate based on the reactive site of factor Xa inhibitor from Bauhinia ungulata seeds. 1267 3

Bauhinia ungulata factor Xa inhibitor (BuXI) inactivates factor Xa and LOPAP, a prothrombin activator proteinase isolated from the venom of Lonomia obliqua caterpillar bristles. The reactive site of the enzyme-inhibitor interaction was explored to design specific substrates for both enzymes. Methionine is crucial for LOPAP and factor Xa substrate interaction, since the change of both Met residues in the substrates abolished the hydrolysis. Synthetic substrates containing the sequence around the reactive site of BbKI, a plasma kallikrein inhibitor, were shown to be specific for trypsin hydrolysis. Therefore, these substrates may be an alternative in studies aiming at a characterization of trypsin-like enzyme activities, especially non-mammalian enzymes.
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PMID:Bauhinia proteinase inhibitor-based synthetic fluorogenic substrates for enzymes isolated from insect midgut and caterpillar bristles. 1271

Benzothiophene-anthranilamide 1 (3-chloro-N-[2-[[(4-fluorophenyl)amino]carbonyl]-4-methylphenyl]benzo[b]thiophene-2-carboxamide) was discovered by high throughput screening to be a highly potent and selective non-amidine inhibitor of human factor Xa with a K(i) of 15+/-4nM. Compound 1 is a selective inhibitor of human factor Xa as suggested by the K(i)((app)) determined for nine other human serine proteases and bovine trypsin. The activity of reconstituted human prothrombinase complex was inhibited by compound 1 when assayed in physiological concentrations of the substrate prothrombin. However, 27-fold higher inhibitor concentrations were needed to achieve the same level of inhibition than were required for the inhibition of free factor Xa, due in part to non-specific binding of the inhibitor to phospholipid under the assay conditions. Failure to demonstrate enzymatic cleavage of compound 1 suggests that compound 1 is solely an inhibitor rather than a substrate for factor Xa. The inhibition of factor Xa by compound 1 was reversible upon dilution of the enzyme/inhibitor mixture. Analyses of the inhibition mechanism with Dixon, Cornish-Bowden, and Lineweaver-Burk plots showed that compound 1 is a linear mixed-type inhibitor with 5-fold higher affinity for free factor Xa than the factor Xa/substrate complex. The linear mixed-type inhibition suggests that compound 1 binds to the active site region of factor Xa, but its binding cannot be fully displaced by the substrate S2222 (1:1 mixture of N-benzoyl-Ile-Glu-Gly-Arg-p-nitroanilide and N-benzoyl-Ile-Glu(gamma-OMe)-Gly-Arg-p-nitroanilide hydrochloride). Thus, the inhibition mechanism for compound 1 is novel compared to most serine protease inhibitors including amidine-containing factor Xa inhibitors, which rely on binding to the S1 pocket of the enzyme active site. Compound 1 represents an attractive, novel structural template for further development of efficacious, safe, and potentially orally active human factor Xa inhibitors.
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PMID:Discovery and characterization of a potent and selective non-amidine inhibitor of human factor Xa. 1273 52

1. Crystallized soy bean trypsin inhibitor, at a concentration of 100 microg./ml., suppressed the production of thrombin from a mixture of prothrombin and blood thrombokinase. The experiment was performed in the presence of 0.011 M oxalate, in order to minimize the possibility of participation by accessory factors which require ionic calcium. The results are in accord with the view that thrombokinase is a trypsin-like enzyme. 2. When a solution of blood thrombokinase was centrifuged at 85,000 g for 120 minutes, almost all the activity remained in the supernate. This supernate activated the supernate from a prothrombin solution which had been similarly centrifuged. The activation of prothrombin by thrombokinase can proceed in the absence of material completely sedimentable in 120 minutes at 85,000 g. 3. An "accelerator" reagent was prepared by treating bovine serum with barium carbonate, and then passing the serum through a column of diatomaceous earth. This "accelerator" was used together with prothrombin, blood thrombokinase, Howell's cephalin, and calcium chloride to compose a five-reagent thrombin-producing system. In this system, no thrombin was produced without thrombokinase. On the other hand, thrombin was produced from prothrombin and thrombokinase, even when all the other reagents were omitted. When calcium was omitted, thrombokinase was able to function; but cephalin and the "accelerator" reagent were ineffective. 4. Quantitative tests indicated that the "accelerator" reagent exerted an effect distinct from those of thrombokinase and cephalin. However, it is not certain whether the "accelerator" reagent functioned as an accessory factor, as a potential source of more thrombokinase, or both. In the experiments reported, thrombokinase was primary to, or necessary for, the effect of "accelerator." 5. The effectiveness of thrombokinase was multiplied a hundred times or more, when complemented by calcium, cephalin, and "accelerator" reagent. Ionic calcium was a necessary component of this complementing system. This may help to explain why removal of calcium ions keeps blood fluid, even though thrombokinase, by itself, is little influenced either by calcium ions or by oxalate.
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PMID:Effect of blood thrombokinase, as influenced by soy bean trypsin inhibitor, ultracentrifugation, and accessory factors. 1324 62

Thrombokinase of the blood, while resembling enterokinase in its role of activator, is more closely analogous to trypsin in its intrinsic origin. It probably arises from a plasma precursor; but it is different from plasmin (fibrinolysin). Like trypsin, thrombokinase can activate prothrombin without the aid of other factors; however, it is potentiated by platelets plus calcium. Unlike certain tissue "thromboplastins," it does not sediment appreciably in 2 hours at 85,000 g. Like trypsin, it hydrolyzes p-toluenesulfonylarginine methyl ester (TAMe). Chromatography on DEAE-cellulose separated thrombin from thrombokinase. The TAMe esterase associated with the thrombokinase fractions was largely suppressed by soybean trypsin inhibitor, while that associated with the thrombin fractions was not. Highly purified thrombokinase was used as starting material; and thrombokinase was eluted in the last major protein band. Under these conditions stepwise elution was as effective as gradient in leading to further purification. The product of 199 liters of bovine plasma was chromatographed in 1 day; and the specific activity was comparable to that attained previously by repeated electrophoretic fractionations. The assembled data suggest that the thrombokinase protein may be approaching homogeneity.
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PMID:Thrombokinase of the blood as trypsin-like enzyme. 1403 95

Thrombokinase has been isolated from bovine plasma by a procedure which begins with the highly purified product of a previously described method, chromatographs it on DEAE-cellulose, and then fractionates it by continuous flow electrophoresis, yielding 0.2 mg per liter of oxalated plasma. The electrophoretic fraction has shown a single boundary in the ultracentrifuge; and its esterase activity on toluenesulfonylarginine methyl ester has been about the same as that of thrombokinase previously isolated by repeated electrophoretic fractionations. Thrombokinase is a euglobulin with minimum solubility near pH 5.0. It is most stable within the pH range 7.5 to 9.5; but there is also a peak in the stability curve near pH 1.8. A few micrograms of thrombokinase per milliliter can activate prothrombin in the presence of EDTA. A few thousandths of a microgram causes rapid production of thrombin in the system: prothrombin, thrombokinase, calcium chloride, phosphatide, "accelerator." But, thrombokinase has less than 1/175 the proteolytic activity of crystallized trypsin.
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PMID:OUTSTANDING CHARACTERISTICS OF THROMBOKINASE ISOLATED FROM BOVINE PLASMA. 1408 Aug 18

In order to examine the possible participation of trypsin-like proteases in the onset and progress of muscular dystrophy, we investigated the expression of the trypsin-like protease in muscular tissues in mdx mice. We found that the mRNAs of several trypsin-like proteases, including hepsin and t-PA, were expressed in the muscular tissues of mdx mice, but at levels not significantly different from normal mice. Since the enzymatic properties of dystrypsin, a muscle trypsin-like protease activated before onset of the disease, are similar to those of thrombin, we investigated the expression pattern of thrombin in mdx mouse muscles. The results showed that prothrombin mRNA is up-regulated in mdx mice at 20-30 days of age but not before the age of 15 days (preclinical). Since protease nexin-1 (PN-1) is known to be a physiological inhibitor of thrombin, we also examined the expression pattern of PN-1. We found that PN-1 transcription and translation is down-regulated in the muscular tissues of mdx mice, before the onset of clinical symptoms. These results suggest that thrombin may be involved in the progression of muscular dystrophy or the regeneration of muscle fibers after the onset of the disease and that the reduced level of PN-1 may enhance the activities stimulate the activities of muscle proteases, including dystrypsin, at a preclinical stage in mdx mice.
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PMID:Expression of trypsin-like proteases and protease nexin-1 in mdx mouse muscles. 1473 57

A novel fibrinolytic enzyme was purified from fermented shrimp paste, a popular seasoning used in Asian countries. The enzyme is a monomer with an apparent molecular weight of 18 kDa, and it is composed primarily of beta-sheet and random coils. The N-terminal amino acid sequence was determined to be DPYEEPGPCENLQVA. It is a neutral protease with an optimal activity from pH 3 to 7. No inhibition was observed with PMSF, Pepstatin A, E64, and 1,10-phenanthroline, but the enzyme was slightly inhibited by EDTA and Cu(2+). It was relatively specific to fibrin or fibrinogen as a protein substrate, yet it hydrolyzed none of the plasma proteins in the studies. In vitro, the enzyme was resistant to pepsin and trypsin digestion. It also had an anticoagulant activity measured with activated partial thrombin time and prothrombin time tests. The novel fibrinolytic enzyme derived from traditional Asian foods is useful for thrombolytic therapy. In addition, this enzyme has a significant potential for food fortification and nutraceutical applications, such that its use could effectively prevent cardiovascular diseases.
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PMID:Novel fibrinolytic enzyme in fermented shrimp paste, a traditional asian fermented seasoning. 1496 60

An inhibitor active against pancreatic trypsin was found in the crude extract from the sea hares Aplysia dactylomelaRang, 1828. A stronger inhibitory activity against human plasma kallikrein was detectable after treating this extract at 60 degrees C, for 30 min. The plasma kallikrein inhibitor (AdKI) purification was achieved by acetone fractionation (80%) v/v, ion-exchange chromatography on Mono Q column and gel filtration chromatography on Superdex 75 column (FPLC system). By the latter a molecular mass of 2900 Da was estimated. The purified inhibitor strongly inhibits human plasma kallikrein with a K(i) value of 2.2 x 10(-10)M, while human plasmin and pancreatic trypsin were inhibited with K(i) values of 1.8 x 10(-9) and 4.7 x 10(-9)M, respectively. Chymotrypsin, pancreatic elastase, pancreatic kallikrein and thrombin are not inhibited. The effect of AdKI on plasma kallikrein was confirmed by the prolongation of activated partial thromboplastin time, using a clotting time assay. The inhibitor did not affect prothrombin time or thrombin time. AdKi is a more specific inhibitor than other serine proteinase inhibitors from marine invertebrates.
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PMID:Purification and preliminary characterization of a plasma kallikrein inhibitor isolated from sea hares Aplysia dactylomela Rang, 1828. 1501 82


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