Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.37 (neutrophil elastase)
 4,078 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Minimodule hollow fibre dialysers, representing clinical dialysis modules on a scale of 1/25, enable quantitative evaluation of the haemocompatibility of hollow fibre membranes in an ex vivo flow system in humans. On line heparinization, adjusted for donor sensitivity, is maintained at a minimal level (approximately 0.14 units/ml). Blood samples collected at the minimodule exit over 30 min are analysed for heparin (anti-Xa activity), activated partial thromboplastin time, fibrinopeptide A, platelet count and beta-thromboglobulin, complement fragment C3a, leucocyte count and polymorphonuclear neutrophil elastase. Initial experiments were performed using well-characterized reference materials: acrylonitrile copolymer (AN 69 HF), polysulphone and cuprophan (CUP). Activation of coagulation and platelets was low for AN 69 HF, intermediate for CUP and greatest for polysulphone, while complement activation was negligible in the presence of AN 69 HF, moderate for polysulphone and most important for CUP. Future applications will be directed towards haemocompatibility screening of prototype membranes with the aim of developing clinical dialysers with improved biocompatibility.
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PMID:Minimodule dialyser for quantitative ex vivo evaluation of membrane haemocompatibility in humans: comparison of acrylonitrile copolymer, cuprophan and polysulphone hollow fibres. 163 26

Peptides containing alpha-aminoboronic acids with neutral side chains are highly effective reaction intermediate analog inhibitors of the serine proteases leukocyte elastase, pancreatic elastase, and chymotrypsin. A protocol has been developed for the synthesis of peptides containing alpha-aminoboronic acids with a basic, 3-guanidinopropyl side chain (boroArg) to extend the range of these compounds to trypsin-like proteases. Ac-(D)Phe-Pro-boroArg-OH, Boc-(D)Phe-Pro-boroArg-OH, and H-(D)Phe-Pro-boroArg-OH were prepared as inhibitors of thrombin based on earlier observations that it has a high affinity for this sequence. All three boronic acids are highly effective, slow-binding inhibitors of thrombin, inhibiting it with final inhibition constants and association rates of: 41 pM, 5.5 x 10(6) M-1 s-1; 3.6 pM, 9.3 x 10(6) M-1 s-1; less than 1 pM, 8.0 x 10(6) M-1 s-1, respectively. Comparison of their binding at equilibrium to thrombin, plasma kallikrein, factor Xa, plasmin, and two-chain tissue plasminogen activator has shown that all three inhibitors have at least 2 orders of magnitude greater affinity for thrombin, with the exception of the acetyl derivative which has a 40-fold greater affinity for thrombin than kallikrein. The boroarginine peptides are effective in inhibiting the action of thrombin in rabbit plasma against its physiological substrates. Activated partial thromboplastin time was significantly prolonged in vitro by all of the inhibitors at concentrations of 50-200 nM. Prolongations of activated partial thromboplastin time were also observed in rabbits after intravenous (40-80 micrograms/kg or subcutaneous (0.20-2 mg/kg) injections of Ac-(D)Phe-Pro-boroArg-OH. Results indicate that this new class of synthetic thrombin inhibitors may be clinically useful as antithrombotic agents.
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PMID:The selective inhibition of thrombin by peptides of boroarginine. 221 2

Human factor IX circulates as a single-chain glycoprotein. Upon activation in vitro, it is cleaved into disulfide-linked light and heavy chains and an activation peptide. After reduction of activated 125I-factor IX, the heavy and light chains are readily identified by gel electrophoresis. A direct, immunoradiometric assay for factor IXa was developed to assess activation of factor IX for proteases that cleaved it. The assay utilized radiolabeled antithrombin III with heparin to identify the active site and antibodies to distinguish factor IX. After cleavage of factor IX by factor XIa, factor VIIa-tissue thromboplastin complex, or the factor X-activating enzyme from Russell's viper venom, antithrombin III bound readily to factor IXa. Cleavage of 125I-factor IX by trypsin, chymotrypsin, and granulocyte elastase in the presence of calcium yielded major polypeptide fragments of the sizes of the factor XIa-generated light and heavy chains. Kallikrein did not cleave the zymogen. Nonactivation cleavage was noted by thrombin, but only in the absence of calcium. When the immunoradiometric assay was used to assess trypsin-cleaved factor IX, the product bound antithrombin III, but not maximally. After digesting with insolubilized trypsin, clotting activity confirmed activation. In contrast, incubation of factor IX with elastase (Takaki A et al, J Clin Invest 71:1706, 1983) or chymotrypsin did not lead to generation of an antithrombin III-binding site, despite their digestion of 125I-factor IX into heavy and light chain-sized fragments. In evaluating activation of factor IX, physical evidence of activation cleavages does not necessarily correlate with generation of an active site.
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PMID:Cleavage and activation of human factor IX by serine proteases. 638 97

The objective of this study was to evaluate and compare the derangement of body homeostatis and the inflammatory response after different types of traumatological operations in patients with multiple injuries. These were determined in a total of 60 operations. The procedures comprised osteosynthesis of the femur (n = 28), the pelvic girdle (n = 11) the spine (n = 8), and facial and basal skull reconstructions (n = 13). Specific and unspecific parameters of the inflammatory response were determined on the morning of the operation, immediately after the procedure, every 6 h on the 1st day and 48 h after the end of surgery. After all types of operations (pelvis, femur, spine, face/basal skull) significant alterations were observed for neutrophil elastase, C-reactive protein, interleukin 6, interleukin 8, antithrombin III, partial thromboplastin time and other parameters. The degree of postoperative changes differed significantly (Kruskal-Wallis test, P < 0.05) among the four types of operations for lactate, heart rate, PO2/FiO2 ratio and nitrogen excretion and showed a strong discriminating tendency for neutrophil elastase and C-reactive protein. The changes were most pronounced after operations on the pelvic girdle, followed by procedures in the femoral, spinal, and facial/basal skull regions. We conclude that a considerable inflammatory response and pronounced disturbance of body homeostasis follow traumatological operative procedures, varying in severity with the type of surgery. Several parameters allow quantitation of the surgical trauma and differentiation between different operations/regions. Further research should focus on the interrelationship between pre-existing preoperative inflammation and the additional trauma inflicted by surgery in patients with severe injuries.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Postoperative homeostatic imbalance after trauma surgical interventions of various degrees in polytrauma]. 748 29

1. In order to characterize the physiological functions of the domain structure of secretory leukoprotease inhibitor (SLPI), the biological capacities of half-length SLPIs, (Ser1-Pro54)SLPI and (Asn55-Ala107)SLPI, were investigated and compared with those of full-length SLPI. 2. The activities of these inhibitors against several serine proteases were determined using synthetic chromogenic substrates. The inhibitory capacity of the C-terminal domain, (Asn55-Ala107)SLPI, was as strong as that of full-length SLPI against human neutrophil elastase (NE), cathepsin G and chymotrypsin. It possessed less trypsin inhibitory activity than intact SLPI. For the N-terminal domain of SLPI, (Ser1-Pro54)SLPI, no inhibitory activity could be detected against the serine proteases tested in this study. 3. The inhibitory activity of (Asn55-Ala107)SLPI against the proteolysis of the natural substrates elastin and collagen by NE was comparable with that of full-SLPI (elastin, IC50 = 907 +/- 31 nM for SLPI, 767 +/- 33 nM for (Asn55-Ala107)SLPI; collagen, IC50 = 862 +/- 36 nM for SLPI, 727 +/- 47 nM for (Asn55-Ala107)SLPI). 4. The binding affinities of full- and half-length SLPIs for heparin were measured by affinity column chromatography. Full-length SLPI showed high affinity for heparin while the binding capacities of both half-length SLPIs were lower. (Concentration of NaCl for elution, 0.45 M for SLPI, 0.24 M for (Ser1-Pro54)SLPI, 0.27 M for (Asn55-Ala107)SLPI). 5. The effects of full-SLPI and (Asn55-Ala107)SLPI on blood coagulation were measured using the activated partial thromboplastin time (APTT). Full-length SLPI prolonged clotting time dose dependently(1.25, 2.5 and 5.0 microM), whereas (Asn55-AlalO7)SLPI had no effect even at the highest concentration.6. In conclusion, the C-terminal domain of SLPI is a promising candidate for the treatment of inflammatory diseases in which participation of neutrophil proteases has been suggested.
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PMID:Pharmacological activity of the C-terminal and N-terminal domains of secretory leukoprotease inhibitor in vitro. 758 15

The ability of recombinant platelet factor 4 and protamine to neutralize heparin after cardiopulmonary bypass was compared in anesthestized baboons. Clotting titration curves of heparinized baboon blood demonstrate an anticoagulant effect of protamine that is not seen with recombinant platelet factor 4. Neither drug caused meaningful changes in central pressures or cardiac output within 30 minutes after injection. After 30 minutes of cardiopulmonary bypass, recombinant platelet factor 4 normalized thrombin times and activated partial thromboplastin times within minutes of injection, but protamine did not. Neither drug altered bleeding times. Recombinant platelet factor 4 caused a species-specific leukopenia in baboons and significantly increased activated complement protein 3 (C3a) more than protamine. However, the increase in plasma C3a was small and neither drug caused a significant increase in plasma neutrophil elastase-alpha 1 proteinase inhibitor complex. We conclude that recombinant platelet factor 4 is effective and safe in baboons, does not have an anticoagulant effect with excess concentration, and reverses in vivo heparin more rapidly than protamine. The data support progression to a clinical trial.
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PMID:Reversal of heparin anticoagulation by recombinant platelet factor 4 and protamine sulfate in baboons during cardiopulmonary bypass. 771 25

Ecotin, a serine protease inhibitor found in the periplasm of Escherichia coli, has been characterized as an extremely potent anticoagulant and reversible tight-binding inhibitor of human factor Xa (FXa). The ecotin gene was cloned by PCR, highly expressed in E. coli, and purified from the E. coli periplasm. The binding of ecotin to FXa was stoichiometric with an equilibrium dissociation constant Ki of 54 pM. The association rate constant was 1.35 x 10(6) M-1 s-1, and the dissociation rate constant, measured in the presence of human leukocyte elastase (HLE) to prevent reassociation of ecotin with FXa, was 6.5 x 10(-5) s-1. Ecotin prolonged clotting time ca. 10-fold at 0.3 microM and at 2 microM in activated partial thromboplastin time and prothrombin time assays, respectively. Ecotin did not effectively inhibit the human plasma proteases thrombin, tissue factor.factor VIIa, factor XIa, activated protein C, plasmin, or tissue plasminogen activator (t-PA); however, it did potently inhibit factor XIIa, plasma kallikrein, HLE, and bovine trypsin and chymotrypsin. Coincubation of ecotin and FXa at 10 microM each resulted in a (ecotin)2.(FXa)2 complex as determined by gel filtration. Dimerization of ecotin alone was measured by fluorescence titration which yielded a Kd of ca. 390 nM. FXa cleaved ecotin slowly at pH 4.0 between M84 and M85. Replacement of the P1 Met84 residue with Arg and Lys led to FXa inhibitors with Ki values of 11 and 21 pM, respectively. The P1 Arg and Lys mutants also significantly inhibited thrombin, factor XIa, activated protein C, plasmin, factor XIIa, kallikrein, and bovine trypsin and chymotrypsin but did not inhibit tissue factor.factor VIIa, t-PA, or HLE.
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PMID:Ecotin is a potent anticoagulant and reversible tight-binding inhibitor of factor Xa. 814 99

Urinary trypsin inhibitor is a glycoprotein with a structure in which two Kunitz-type inhibitory domains are linked in a row. We isolated two genes encoding the 70 amino acid sequence from the 78th amino acid (Thr) to the C-terminal and the 68 amino acid sequence from the 80th (Ala) to the C-terminal of human urinary trypsin inhibitor, both which correspond to the second Kunitz-type inhibitory domain, and then constructed expression plasmids by ligating it to the E. coli alkaline phosphatase signal peptide gene. These plasmids under the control of the tryptophan promoter expressed the second domain in E. coli strain JE5505 which lacks the membrane lipoprotein. The recombinant second domain purified from the culture supernatant of the transformant inhibited trypsin, plasmin, leukocyte elastase and chymotrypsin which are known to be inhibited by urinary trypsin inhibitor. In addition it inhibited blood coagulation factor Xa and plasma kallikrein in a concentration dependent and competitive manner, and significantly prolonged the plasma-based activated partial thromboplastin time (APTT). The truncated natural counterpart obtained by a limited degradation of human urinary trypsin inhibitor also revealed the identical inhibitory activities.
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PMID:Novel factor Xa and plasma kallikrein inhibitory-activities of the second Kunitz-type inhibitory domain of urinary trypsin inhibitor. 819 13

In a previous report, we described the molecular cloning, expression, and partial characterization of a second human tissue factor pathway inhibitor (TFPI), which we designated as TFPI-2 [Sprecher, C. A., et al. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 3353-3357]. Recombinant TFPI-2 inhibited the amidolytic activity of trypsin as well as that of factor VIIa in complex with tissue factor. TFPI-2 recently has been shown to be identical to placental protein 5 (PP5), a glycoprotein originally isolated from placenta that exhibits serine protease inhibitory activity. In the present study, we have examined TFPI-2/PP5 for its ability to inhibit a number of serine proteases involved in blood coagulation and fibrinolysis, inasmuch as TFPI-2/PP5 prolonged the coagulation time of human plasma induced by either tissue factor or contact activation in a dose-dependent manner. In addition to its ability to inhibit the amidolytic and proteolytic activities of the factor VIIa-tissue factor complex, TFPI-2/PP5 strongly inhibited the amidolytic activities of human factor XIa, human plasma kallikrein, and human plasmin with Ki values of 15, 25, and 3 nM, respectively. TFPI-2/PP5 was also a weak inhibitor of the activation of factor X by a complex of human factor IXa and poly(lysine) with an apparent Ki of 410 nM. Heparin markedly enhanced the ability of TFPI-2/PP5 to inhibit factor VIIa-tissue factor both in the solution phase and on cell surfaces. In addition, heparin augmented the inhibition of human factor Xa amidolytic activity at relatively high levels (10-100 nM) of TFPI-2/PP5. No significant inhibition of glandular kallikrein, urinary plasminogen activator, tissue plasminogen activator, human activated protein C, human factor Xa, human thrombin, or leukocyte elastase was observed when these proteases were incubated with TFPI-2 in the absence of heparin.
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PMID:Inhibitory properties of a novel human Kunitz-type protease inhibitor homologous to tissue factor pathway inhibitor. 855 84

This study describes the present knowledge regarding the clinical application of argatroban, a direct competitive thrombin inhibitor for heparin-intolerant patients, including those with congenital and acquired antithrombin III deficiencies, those with heparin-induced thrombocytopenia, and those with high levels of polymorphonuclear granulocyte elastase. These patients are often associated with intracircuit clot formation with heparin anticoagulation during extracorporeal circulation. Therefore, argatroban may be chosen as one of the alternate anticoagulants. Because the anticoagulant effect of argatroban is reflected in the prolongation of activated thromboplastin time, monitoring is easy, similar to that for heparin. Because argatroban has a fast acting anticoagulant effect without any cofactors such as antithrombin III, this drug is a favorable anticoagulant for heparin-intolerant patients with antithrombin III deficiencies requiring extracorporeal circulation. In adverse reactions to heparin, heparin acts as an antigen after complexing with platelet factor 4, which leads to life-threatening heparin-induced thrombocytopenia. As argatroban prevents heparin-induced platelet aggregation, it is effective for use as a therapeutic anticoagulant. In other clinical applications, heparin decreases antithrombin activity and causes intracircuit clot formation during extracorporeal circulation when the polymorphonuclear granulocyte elastase level is very high. The antithrombin activity shows less decrease when argatroban is substituted for heparin. These findings indicate that argatroban is a useful alternative anticoagulant in these heparin-intolerant patients.
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PMID:Application of argatroban, direct thrombin inhibitor, in heparin-intolerant patients requiring extracorporeal circulation. 928 75


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