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:3.4.21.7 (plasmin)
9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rates of hydrolysis of the newly developed peptide chromogenic substrates S-2160 (N-Bz-Phe-Val-Arg-pNA, HCl), S-2238 (H-D-Phe-Pip-Arg-pNA, 2HCl), S-2222 (N-Bz-Ile-Glu-Gly-Arg-pNA, HCl), and S-2251 (H-D-Val-Leu-Lys-pNA, 2HCl) from AB Kabi Peptide Research and Chromozym TH (Z-Gly-Pro-Arg-pNA, HCl) from Pentapharm Limited were tested against highly purified preparations of human plasmin, bovine trypsin, human alpha thrombin, and bovine factor Xa. S-2160, S-2238, and Chromozym TH are sensitive to thrombin, Chromozym TH and S-2238 exhibiting a substantially greater sensitivity than S-2160. All 3 substrates are insensitive to factor Xa but hydrolyzed to varying degrees by plasmin and trypsin. In contrast, S-2222 is sensitive to Xa and insensitive to thrombin. S-2251 is relatively plasmin-specific, being resistant to the clotting enzymes thrombin and Xa. S-2251 exhibits even greater sensitivity to the SK-plasmin complex than to plasmin. In addition, the substrate Chromozym PK (N-Bz-Pro-Phe-Arg-pNA, HCl) was evaluated and found to be relatively specific for plasma kallikrein. Assays for antithrombin III and heparin using S-2222 as the substrate and factor Xa as the enzyme, plasma plasminogen and plasmin inhibitors using S-2251 as the substrate, and plasma prekallikrein and kallikrein inhibitors using Chromozym PK as the substrate have been developed. Synthetic peptides mimicking amino acid sequences adjacent to proteolytic activation cleavage of plasma serine protease precursors appear to be sensitive and relatively specific tools applicable to kinetical and clinical studies of these enzymes and their inhibitors.
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PMID:Serine protease specificity for peptide chromogenic substrates. 14 72

Rates of hydrolysis of the newly developed peptide chromogenic substrates S-2160, S-2238, S-2222 and S-2251 and Chromozym TH were tested against highly purified preparations of human plasmin, bovine trypsin, human alpha-thrombin, and bovine factor Xa. S-2160, S-2238, and chromozym TH are sensitive to thrombin, Chromozym TH and S-2238 exhibiting a substantially greater sensitivity than S-2160. All three substrates are insensitive to factor Xa but hydrolyzed to varying degrees by plasmin and trypsin. In contrast, S-2222 is sensitive to factor Xa and insensitive to thrombin. S-2251 is relatively plasmin-specific. In addition, the substrate Chromozym PK was evaluated and found to be relatively specific for plasma kallikrein. Clinically useful assays for antithrombin III and heparin using S-2222 as the substrate and factor Xa as the enzyme, plasma plasminogen and plasmin inhibitors using S-2251 as the substrate, and plasma prekallikrein and kallikrein inhibitors using Chromozym PK as the substrate have been developed.
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PMID:Sensitivity and specificity of plasma serine protease chromogenic substrates. 14 51

To characterize the mode of action of heparin, the kinetics of inhibition of thrombin, factor Xa, and plasmin by antithrombin III was studied without and in the presence of heparin. Following the concentration dependence of inactivation a linear dependence was found between the apparent first-order inactivation rate constant and the anti-thrombin III concentration. This behaviour is typical of enzyme-activator interaction. Values of kinetic constants of the inactivation reaction could be determined. Thus, heparin acts obviously as an activator of the enzymes and enhances their affinity for antithrombin III.
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PMID:Role of heparin in the interaction of serine proteinases with antithrombin III. 15 69

Plasmin does not activate factor X into the enzyme--factor Xa. On the contrary, the enzyme inactivates factor X, rendering it incapable of conversion into factor Xa during incubation in 25% sodium citrate. After proteolysis by plasmin the prothrombin preparations contaminated with factor X lose their ability to generate thrombin. This ability is partially restored by an addition of factor X.
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PMID:[Inactivation of factor X by plasmin]. 15 77

Changes of prekallikrein in the cases with DIC were investigated, i.e., DIC cases including disseminated metastasis of gastric cancer, acute promyelocytic leukemia and endotoxin shock. Therefore, the trigger substances for this paper were the pathologic cells of the leukemia, the cultured well differentiated adenocarcinoma cells and endotoxin. (1) The lysates of the pathologic cells of the leukemia and the cultured cells showed prekallikrein activation. Endotoxin showed prekallikrein activation via factor XII. (2) Serine proteases (factor Xa, thrombin, plasmin and trypsin) activated prekallikrein in the plasma and the purified prekallikrein. (3) Antithrombin III, aprotinin and FOY inhibited prekallikrein activation. Antithrombin III was promoted by heparin in its inhibitory effect.
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PMID:Changes of prekallikrein in the cases with disseminated intravascular coagulation syndrome. 16 Jan 91

Twenty peptide-4-methylcoumarin amides (MCA) were newly synthesized and tested as possible substrates for alpha-thrombin, factor Xa, kallikreins, urokinase, and plasmin. These fluorogenic peptides contained arginine-MCA as the carboxyl-terminus. Release of 7-amino-4-methylcoumarin was determined fluorometrically. Of these peptides, the following were found to be specific substrates for individual enzymes: Boc-Val-Pro-Arg-MCA for alpha-thrombin, Boc-Ile-Glu-Gly-Arg-MCA, and Boc-Ser-Gly-Arg-MCA for factor Xa, Z-Phe-Arg-MCA for plasma kallikrein, Pro-Phe-Arg-MCA for pancreatic and urinary kallikreins, and glutaryl-Gly-Arg-MCA for urokinase. Moreover, these peptide-MCA substrates were resistant to plasmin.
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PMID:New fluorogenic substrates for alpha-thrombin, factor Xa, kallikreins, and urokinase. 59 14

Derivatives of benzamidine inhibit competitively the activity of the serine proteinases trypsin, plasmin, thrombin, and of the clotting factor Xa. The inhibitor activities (Ki-values) of various benzamidine derivatives against the several enzymes were compared. Besides parallels, deviations in the corresponding structure-activity relationships were found. From these results it is concluded that the similar enzymes exhibit certain differences in the structure of the primary and secondary binding sites.
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PMID:Inhibition of serine proteinases by benzamidine derivatives. 61 39

Synthetic procedures have been developed for the preparation of peptides of arginine chloromethyl ketone and applied in the preparation of affinity labels which correspond to the -Pro-Phe-Arg- C terminus of bradykinin, a physiological cleavage site of kallikrein in kininogen. Two such reagents, Ala-Phe-ArgCH2C1 and Pro-Phe-ArgCH2C1, proved to be highly effective as well as selective affinity labels for human plasma kallikrein. For example, Pro-Phe-ArgCH2C1 inactivates plasma kallikrein 50% in 24 min at a concentration of 2 x 10(-8)M, while other trypsin-like proteases are less susceptible in inactivation than kallikrein, differing by a factor of 48 for plasmin and factors of 10(2)-10(5) for factor Xa, thrombin, and urokinase. The affinity of human plasma kallikrein for Ala-Phe-ArgCH2C1 (Ki = 0.078 micron) is about 60 times that for Ala-Phe-LysCH2C1(Ki = 4.9 micron), whereas human plasmin exhibits about the same affinity for the former affinity label (Ki = 1.3 micron) as for the latter (Ki = 0.83 micron). The rate constants for the irreversible step of the affinity labeling reaction, k2, are similar for affinity labels tested with the individual proteases: 0.35 min-1 for plasma kallikrein and 0.18 min-1 for plasmin.
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PMID:Synthesis of peptides of arginine chloromethyl ketone. Selective inactivation of human plasma kallikrein. 72 86

Factor XII was purified approximately 14 000-fold from bovine plasma by ammonium sulfate fractionation followed by heparin-agarose, DEAE-Sephadex, CM-cellulose, arginine-agarose, and benzamidine-agarose column chromatography. By this method, about 15 mg of protein was purified from 15 L of plasma with an overall yield of 18%. The purified protein was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and amino-terminal analysis. Bovine factor XII is a glycoprotein with a mol wt of 74 000 as determined by sedimentation equilibrium centrifugation. It contains 13.5% carbohydrate including 3.4% hexose, 4.7% N-acetylhexosamine, and 5.4% N-acetylneuraminic acid. Factor XII is a single polypeptide chain with an NH2-terminal sequence of Thr-Pro-Pro-Trp-Lys-Gly-Pro-?-Lys-His. This sequence is homologous to the reactive-site regions of a number of protease inhibitors. The amino acid sequence of a carboxyl-terminal fragments prepared by cyanogen bromide digestion was found to be Leu-Cys-Ala-Gly-Phe-Leu-Glu-Gly-Gly-Thr-Asp-Ala-Cys-Gln-Gly-Asp-SER-Gly-Gly-Pro-Leu-Val-Cys-Glu-Asp-Glu. This sequence is homologous with the active site of a number of plasma serine proteases including thrombin, factor IXa, factor Xa, and plasmin. These data indicate that bovine factor XII is a precursor to a serine enzyme with an inhibitor sequence and a catalytic site located in the same single polypeptide chain.
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PMID:Isolation and characterization of bovine factor XII (Hageman factor). 86 Dec 10

Most of the linkage of atherosclerosis and thrombosis with estrogens is epidemiologic in origin. Although the effects of estrogens on the mechanisms of hemostasis are wide ranging, many are benign; only a few may account for thrombus formation. Platelet function tests have provided extensive but contradictory data, and interpretation is limited because it is uncertain whether a rise in one or more of these parameters is a primary or secondary effect. The most consistent effects of estrogens on coagulation proteins are elevations of fibrinogen; factors II, VII, IX, X, and XII; protein C; and plasminogen. Although these elevations have been attributed to the estrogenic component in oral contraceptives, the progestogen concentration may also influence these increases. Among other coagulation proteins studied, the following are unaffected by oral contraceptive use: factors V, VIII, and XI; prekallikrein; and high-molecular-weight kininogen. In contrast, protein S values are decreased. The plasma concentration of plasmin inhibitor is unchanged, whereas both proteinase inhibitor and macroglobulin are significantly increased by oral contraceptive use. Cl esterase inhibitor is decreased in women taking oral contraceptives and correlates with the increase in Hageman factor. Antithrombin III is one plasma inhibitor for which a decrease in quantity and activity have been associated with a thrombotic tendency in humans. Although data on estrogen-associated changes in the quantity of antithrombin III have been conflicting, the ability of plasma to inhibit factor Xa is significantly reduced in a dose-dependent manner among pre- and postmenopausal estrogen users.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Estrogen-associated thromboembolism. 134 94


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