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)

Alteration of the coagulation-fibrinolysis system was examined in patients on maintenance hemodialysis. The mean values of fibrinogen, factor V, factor VII, factor VIII, vWF (activity and antigen), factor IX and factor XI were significantly higher in these patients than in control subjects (p less than 0.01), but factor XII alone was significantly lower. Fibrinolytic parameters (euglobulin lysis time, fibrin plate lysis, fibrin degradation products and alpha 2-plasmin inhibitor-plasmin complex) suggested a hyperfibrinolytic state and plasmin generation in the patients' circulation. These findings suggest that the alteration of the coagulation-fibrinolysis system is aggravated by repeated hemodialysis, either by the influence of the dialyzer itself or heparin.
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PMID:Coagulation and fibrinolysis in patients with chronic renal failure on maintenance hemodialysis. 274 46

Plasminogen kringle 1+2+3 (K1-3) containing lysine-binding sites inhibited the reaction of plasmin with alpha 2-plasmin inhibitor (alpha 2PI), in a rate assay using a synthetic chromogenic substrate, S-2251. However, K1-3 did not inhibit the reaction to any degree between alpha 2PI and mini-plasmin which lacked the kringle 1 to 4 portion of plasmin. These results suggest that K1-3 blocked the binding of alpha 2PI to the lysine-binding site of plasmin. In the urokinase (UK)-induced fibrinolysis, K1-3 shortened the human plasma clot lysis time at low concentration (0.5-6 microM), and prolonged the lysis time at a high concentration (20 microM). Similar results were obtained in the lysis time of a fibrin clot consisting of plasminogen, fibrinogen and alpha 2PI isolated from human plasma. The kringle 4 (K4) of human plasminogen did not accelerate human plasma clot lysis at any concentration (1.2-24.1 microM). Furthermore, in the tissue plasminogen activator (TPA)-induced fibrinolysis, K1-3 also shortened both the lysis time of human plasma clot and fibrin clot as observed in UK-induced fibrinolysis, but K4 did not. The above findings indicate that the reaction of alpha 2PI with the lysine-binding site of plasmin is involved in the inhibition of plasmin activity by alpha 2PI, and in the presence of an inhibitor of this reaction, the balance of coagulofibrinolytic activity in plasma will be shifted towards the fibrinolytic side.
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PMID:Effects of kringles derived from human plasminogen on fibrinolysis in vitro. 282 51

We have isolated three cDNA clones for human alpha 2-plasmin inhibitor (alpha 2-PI). Two clones are from human hepatoma cell line, Hep G2, and cover the entire protein coding region plus the 3'-flanking region up to the poly(A) sequence, and the other clone is from human liver and contains the carboxyl-terminal half. The total length of the cDNAs is 2.29 kb, corresponding to more than 95% of the full-length mRNA. alpha 2-PI seems to consist of 452 amino acid residues plus 39 amino acid residues for the signal peptide. The amino acid sequence shows 23 to 28% homology to those of five other protease inhibitors, plasminogen activator inhibitor (PAI), protein C inhibitor (PCI), alpha 1-antitrypsin (alpha 1-AT), antithrombin III (AT III), and alpha 1-antichymotrypsin (alpha 1-AC). alpha 2-PI seems to be the most distantly related among these inhibitors. Comparison of the phylogenetic trees of proteases and their inhibitors indicates that four proteases, namely elastase (or trypsin), chymotrypsin, plasminogen activator, and thrombin, may have evolved concurrently with the corresponding inhibitors. However, alpha 2-PI and PCI seem to have evolved asynchronously from their substrates. The data suggest that alpha 2-PI may originally have inhibited some protease other than plasmin, and protein C may have had an inhibitor different from the present one early in its evolutionary history.
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PMID:Structure of human alpha 2-plasmin inhibitor deduced from the cDNA sequence. 283 Feb 48

Plasmin activity and fibrin degradation products (FDP) are found in alpha 2-plasmin inhibitor (alpha 2-PI) deficient plasma only when clotted, but are not found when the plasma is not clotted. To determine whether fibrin itself could initiate fibrinolysis without activating coagulation enzymes, fibrin monomers were prepared and added to alpha 2-PI deficient plasma. The addition of fibrin monomers resulted in the generation of plasmin activity, a marked increase in FDP concentration, and the release of 125I from 125I-labeled fibrin monomers. Replenishment of the deficient plasma with purified alpha 2-PI abolished the effects of fibrin monomers on the initiation of fibrinolysis. Neither development of plasmin activity, increase of FDP, nor release of 125I was observed. These findings indicate that fibrinolysis can be induced by fibrin itself without activation of coagulation cascade and the induction of fibrinolysis is efficiently blocked by alpha 2-PI.
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PMID:The initiation of fibrinolysis in alpha 2-plasmin inhibitor deficient plasma. Role of fibrin. 293 89

The role of the fibrinolytic enzyme system in inflammatory joint disease has been addressed by several experimental approaches. In our study we examined synovial fluid (SF) in several different diseases for alpha 2-plasmin inhibitor-plasmin complexes by an enzyme linked immunosorbent assay (ELISA). These complexes are present in both rheumatoid and nonrheumatoid SF, with highest levels seen in septic arthritis. Thus the plasminogen system is intact in inflammatory SF, and plasmin may play a role in the local inflammatory process.
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PMID:Alpha 2-plasmin inhibitor-plasmin complexes in synovial fluid. 294 85

We performed a hemostatic evaluation in detail in a patient with suspected amyloidosis who was suffering from several bleeding episodes. He had a shortened euglobulin clot lysis time, decreased alpha 2-plasmin inhibitor (alpha 2-PI), decreased plasminogen, elevated tissue-type plasminogen activator (t-PA), elevated plasmin-alpha 2-PI complex, and decreased ratio of ristocetin cofactor to von Willebrand factor (vWF) antigen. Fibrinogen and fibrin/fibrinogen degradation products levels fluctuated, with abnormal values on several occasions. On crossed immunoelectrophoresis, plasmin-alpha 2-PI complex and vWF fragment were demonstrated in the patient plasma. These abnormal findings and bleeding symptoms improved following the administration of tranexamic acid. Discontinuation of tranexamic acid resulted in deterioration of these parameters. These observations indicate that pathologic fibrinolysis (continuous intravascular plasmin generation) characterized by the consumption of alpha 2-PI and plasminogen, formation of plasmin-alpha 2-PI complex, and fragmentation of vWF contributed to the bleeding in this patient. It is important to recognize excessive fibrinolysis as the underlying cause of bleeding in these patients, since specific treatment with antifibrinolytic agents is effective in controlling the bleeding.
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PMID:Excessive fibrinolysis in suspected amyloidosis: demonstration of plasmin-alpha 2-plasmin inhibitor complex and von Willebrand factor fragment in plasma. 294 78

Three monoclonal antibodies to alpha 2-plasmin inhibitor (alpha 2PI) were characterized. The first, JTPI-1, was directed against the reative site of alpha 2PI and inhibited antiplasmin activity by interfering with the formation of alpha 2PI-plasmin complexes. The avidity of JTPI-1 to the preformed alpha 2PI-plasmin complex was markedly lower than that to free alpha 2PI, which made this antibody useful for measuring the free alpha 2PI in plasma. The second, JTPI-2, recognized an epitope in the C-terminal fragment of alpha 2PI (11,000 daltons [11 K]) that was cleaved from alpha 2PI by plasmin upon complex formation but remained noncovalently attached to the complex. However, binding of JTPI-2 to alpha 2PI was not inhibited by the C-terminal 26-residue peptide containing the plasminogen-binding site and had no effect on the function of alpha 2PI. These data suggested that JTPI-2 recognized an epitope between the C-terminal 26-residue peptide and the reactive site. The third, JTPI-3, bound the alpha 2PI-plasmin complex (150 K) as well as alpha 2PI. Binding was inhibited by the N-terminal 12-residue peptide of alpha 2PI, but factor XIII-catalyzed cross-linking of alpha 2PI to fibrin was not inhibited by JTPI-3. These results suggested that the antibody recognized an epitope near the N terminus. These three monoclonal antibodies were useful for analyzing the mechanism of interaction between alpha 2PI and plasmin.
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PMID:Monoclonal antibodies to discrete regions in alpha 2-plasmin inhibitor. 294 79

Plasma levels of alpha 2-plasmin inhibitor (alpha 2PI), plasmin-alpha 2PI complex and cross-linked fibrin derivatives (XDP) were measured in 8 patients (12 episodes) with thromboembolic disorders on the initial administration of urokinase. In conjunction with a decrease in plasma alpha 2PI activity and antigen, plasmin-alpha 2PI complex increased following urokinase infusion in all cases except one who received a low dose (60,000 units) of urokinase. However, changes in XDP were variable among the patients. Plasma XDP level increased markedly in one, moderately in 4, slightly in one, and remained unchanged in 6 cases (episodes). The increment of plasma XDP correlated (r = 0.804, p = 0.003) with the dose of urokinase administered, but was independent of changes in plasmin-alpha 2PI complex. The plasma XDP elevation was associated with clinical improvement. These results suggest that simultaneous measurements of XDP and plasmin-alpha 2PI complex in plasma would be valuable for the pharmacological or hemostatic assessment of thrombolytic therapy.
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PMID:Evaluation of fibrinolytic therapy by measuring cross-linked fibrin derivatives and plasmin-alpha 2-plasmin inhibitor complex in plasma. 296 45

We have previously demonstrated that increasing factor XIII concentrations above that present in plasma (1 U/mL) results in the formation of very high molecular weight alpha fate polyacrylamide and agarose gel electrophoresis (SDS-PAGE). In this report, we have examined the effect of such crosslinking on plasmic susceptibility of fibrin prepared from purified fibrinogen and from plasma in the presence of factor XIII concentrations between 0 and 10 U/mL. The crosslinking achieved with purified fibrinogen at 1 U/mL factor XIII increased resistance to plasmic degradation by 32% as measured in a radiolabeled clot lysis system. However, further increases in plasmic resistance occurred at factor XIII concentrations of 2 and 10 U/mL, the latter decreasing the lysis rate to 45% of that which occurred in the absence of factor XIII. To achieve the same rate of clot lysis with fibrin formed using 10 U/mL rather than 1 U/mL of factor XIII, an increase in plasmin concentration of up to 4.2-fold was required. Similar results were obtained using clots prepared from plasma in the presence of factor XIII concentrations greater than 1 U/mL. Since the alpha 2-plasmin inhibitor content was the same for fibrin at 1 or 10 U/mL factor XIII, the increasing plasmic resistance could not be attributed to increased binding of the inhibitor. We conclude that fibrin prepared in the presence of factor XIII at concentrations exceeding that in plasma shows increased resistance to plasmic degradation, which is likely explained by the formation of very high molecular weight alpha polymer chains.
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PMID:Increased resistance to plasmic degradation of fibrin with highly crosslinked alpha-polymer chains formed at high factor XIII concentrations. 296 27

Certain Group A beta-hemolytic streptococci express a receptor that is capable of specifically binding the human plasma protease plasmin. Once bound, plasmin remains enzymatically active and is unregulated by its naturally occurring inhibitor alpha-2-antiplasmin (Lottenberg, R., C. C. Broder and M. D. P. Boyle, 1987. Infect. Immun. 55: 1914-1918). In this study certain characteristics of the interaction between plasmin and the receptor expressed on a group A beta-hemolytic streptococcus, strain 64/14, were examined. Binding occurred optimally at physiologic pH and ionic strength. The KD was 5 x 10(-11) M and there were approximately 800 receptors per bacterium. Mouse passage of strain 64 had no significant effect on the KD of the receptor. Binding of plasmin to the bacteria was inhibited by lysine and epsilon-aminocaproic acid in a concentration dependent manner. Similarly these amino acids would displace pre-bound plasmin from the bacteria. These findings suggest a role for plasmin's high affinity lysine binding site in the interaction of plasmin with the bacteria.
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PMID:Characterization of the interaction of human plasmin with its specific receptor on a group A streptococcus. 297 21


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