Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastric juice from 15 normals, 20 patients with gastric ulcer and 14 patients with erosive haemorrhagic gastroduodenitis was investigated in respect of its activity on unheated and heated fibrin plates and its content of FDP and plasminogen or plasmin with immunochemical methods. Gastric juice from normals showed no activity on unheated and heated fibrin plates, and no FDP or plasminogen could be demonstrated. In the patients with gastric ulcer the gastric juice showed little or no fibrinolytic activity on fibrin plates except in 2, who had regurgitation of duodenal juice and neutral pH of the juice. These patients had equally high activity on heated as on unheated plates and no plasmin could be demonstrated. It was shown that this activity was not due to fibrinolysis, but to non-specific proteolytic activity (probably trypsin). The patients with erosive haemorrhage gastroduodenitis exhibited quite a different picture. The gastric juice from these patients showed extremely high activity on fibrin plates, the activity was higher on unheated than on heated plates. The activity was inhibited in vitro by addition of EACA and in vivo after administration of AMCA. The occurence of plasmic could be demonstrated directly immunologically in the gastric juice. By comparsion of plasmin and trypsin in various assays it could further be improved that the gastric juice in these cases contained plasminogen activator and plasmin. The patients with erosive haemorrhagic gastroduodenitis showed no increase in fibrinolysis in the blood, but low values for plasminogen and alpha2-M, and the serum contained FDP. These findings in the blood and gastric juice were interpreted as signs of local fibrinolysis in the stomach and duodenum. There is reason to assume that this gastric fibrinolysis contributes substantially to the bleeding tendency. The effect of administration of AMCA on fibrinolytic activity and the haemorrhage lends support to the assumption of such a mechanism.
 ...
PMID:Gastric fibrinolysis. 0 Aug 7

Proteoglycan monomer (D1) and aggregate (A1) preparations were isolated from 4 M guanidinium chloride extracts of the Swarm rat chondrosarcoma. When EDTA, 6-aminohexanoic acid, and benzamidine were present in the solutions, the D1 preparation contained a single component (SO = 23 S), and the A1 preparation contained 30% monomer (SO = 23 S) and 70 percent aggregate (SO = 111 S). In the absence of EDTA, 6-aminohexanoic acid, and benzamidine, the A1 preparations contained only small proteoglycan fragments, indicating that extensive enzymatic degradation had occurred. The composition of the proteoglycan monomer was different from that of proteoglycan monomer preparations from normal hyaline cartilages in that it did not contain keratan sulfate and chondroitin 6-sulfate; only chondroitin 4-sulfate was found. The A1 preparation from the chondrosarcoma contained only one link protein, which was like the smaller (molecular weight of 40,000) of the two link proteins present in A1 preparations from bovine nasal cartilage. When the A1 preparation from the chondrosarcoma was treated with chondroitinase ABC and trypsin and the digest was chromatographed on Sepharose 2B, a complex was isolated which contained the link protein and the segments of the protein core from the hyaluronic acid-binding region of the proteoglycan molecules.
 ...
PMID:Isolation and characterization of proteoglycans from the swarm rat chondrosarcoma. 12 82

The primary inhibitor of plasmin in human plasma was purified by a four-step procedure involving fractional (NH(4))(2)SO(4) precipitation, ion-exchange chromatography on a column of DEAE-Sepharose CL-6B and affinity chromatography on both a plasminogen-CH-Sepharose 4B column and a column of 6-aminohexanoic acid covalently coupled through the carboxylate function to AH-Sepharose 4B. No impurities in the final preparation could be detected when tested by immunoelectrophoresis against a range of specific antisera or against rabbit anti-human serum. On polyacrylamide-gel electrophoresis the inhibitor preparation showed a single band. The dissociation constant for the inhibitor-plasminogen complex was determined to be approx. 3mum at pH7.8. The reactions of the inhibitor with human plasmin and with bovine trypsin were studied. Comparison of the results obtained confirms the hypothesis previously presented, namely that the reaction of the inhibitor with plasmin involves at least two steps, the initial rapid formation of an enzyme-inhibitor complex followed by a slow irreversible transition to another complex. The results also indicate that the reaction of the inhibitor with trypsin involves just a single, irreversible step, so that this reaction seems to be less complicated than that of the inhibitor with plasmin. The ways in which 6-aminohexanoic acid influences the reactions were studied. The same value for the dissociation constant (approx. 26mum) for 6-aminohexanoic acid is obtained for both its effect on the reaction of the inhibitor with trypsin and for competitive inhibition of trypsin. The inhibitory effect of 6-aminohexanoic acid thus seems to be due to its blocking of the active site of trypsin. In contrast with this, the inhibitory effects of l-lysine and 6-aminohexanoic acid on the inhibitor-plasmin reaction occur at concentrations much too low to affect the active site of plasmin. The possible dependence of the reaction of the inhibitor with plasmin on a second site(s) on plasmin is discussed.
 ...
PMID:Purification and reaction mechanisms of the primary inhibitor of plasmin from human plasma. 15 22

1,1'-Carbonyldiimidazole, a carbonylating reagent, has been shown to be suitable for the activation of cross-linked agaroses for affinity chromatography. The activated matrix (an imidazolyl carbamate) is relatively stable to hydrolysis but smoothly reacts with N-nucleophiles such as those present in either affinity chromatography ligands or leashes, e.g. ethylenediamine or 6-aminohexanoic acid. If butylamine was attached via the 1,1'-carbonyldiimidazole method, the resulting product was devoid of charged groups and thus had the same titration curve as agarose. The suitability of this new matrix for affinity chromatography was demonstrated by the successful purification of trypsin by several different systems.
 ...
PMID:A novel method of activation of cross-linked agaroses with 1,1'-carbonyldiimidazole which gives a matrix for affinity chromatography devoid of additional charged groups. 42 1

The influence of EACA on C1 in whole human serum and on C1 and C (see article) as isolated molecules was assessed hemolytically. There was selective inhibition of C1 without effect on the levels of C4, C2, C3, and C9 in whole human serum that was reversed by dialysis. EACA was found to inhibit the intrinsic activation of C1 without inhibiting the already active molecule. This was confirmed by the capacity of trypsin to uncover C1 activity in cellular intermediates formed by C1 treated with EACA that did not evolve in the absence of this extrinsic activating mechanism. Inasmuch as the trypsin-dependent recovery of C1 was incomplete, an effect on binding cannot be excluded.
 ...
PMID:Inhibition by epsilon-aminocaproic acid of the activation of the first component of the complement system. 116 67

Plasmin inhibition by alpha 2-antiplasmin (alpha 2AP) is regulated by the vascular components fibrin(ogen) fragments, plasminogen and lipoprotein (a). Kinetic analysis demonstrates that CNBr-derived fibrinogen fragments completely protect plasmin from alpha 2AP. Plasminogen and 6-aminohexanoic acid decrease the rate of inhibition by 5- and 10-fold respectively. These studies show that CNBr-derived fibrinogen fragments and 6-aminohexanoic acid bind plasmin kringle(s) with binding constants of 2 micrograms/ml and 120 microM respectively, and that plasminogen binds to alpha 2AP with an affinity of 0.5 nM. The unmodulated inhibition is not effected by the presence of lipoprotein (a), but in the presence of protective CNBr-derived fibrinogen fragments the rate of inhibition is increased by the presence of the lipoprotein. The kinetics demonstrate that lipoprotein (a) binds to CNBr-derived fibrinogen fragments with an affinity of 4 nM, displacing plasmin from the protective surface. In addition, tissue-type plasminogen activator and trypsin inhibition by alpha 2AP is not slowed by the presence of CNBr-derived fibrinogen fragments or plasminogen (Pg), respectively. These kinetics suggest that the initial reversible interaction between plasmin and alpha 2AP is mediated by binding of the inhibitor to the kringle 1 domain of plasmin, with a reversible inhibition constant (Ki) of 5.0 x 10(-10) M. Under conditions where this kringle-inhibitor interaction is blocked, the reversible inhibition still occurs between the plasmin and alpha 2AP, but the initial Ki is increased to 5.0 x 10(-9) M. These data suggest that, in the circulation, plasmin inhibition by alpha 2AP may be down-regulated by fibrin, fibrin(ogen) fragments and Pg, but up-regulated by lipoprotein (a) in the presence of fibrin or fibrin(ogen) fragments. The lipoprotein (a)-mediated promotion of plasmin inhibition may provide an additional mechanism by which the lipoprotein impairs fibrinolysis and promotes atherosclerosis.
 ...
PMID:Lipoprotein (a) promotes plasmin inhibition by alpha 2-antiplasmin. 138 85

An adsorbent for high-performance affinity chromatography of trypsins was prepared, based on a micro-particulate polyvinyl alcohol gel for high-performance liquid chromatography, Asahipak GS-gel. After the hydroxyl groups had been activated with 1,1'-carbonyldiimidazole, 6-aminohexanoic acid was coupled as a spacer, then p-aminobenzamidine, a specific ligand for trypsin-family enzymes, was immobilized on the spacer. Fluorometric detection of eluted protein and on-line assay of enzyme activity using a fluorogenic substrate, peptidylmethylcoumarylamide, made it possible to attain very high sensitivity. Microgram amounts of bovine trypsin and Streptomyces griseus trypsin could easily be analyzed in a short time (less than 1 h).
 ...
PMID:High-performance affinity chromatography of trypsins on Asahipak GS-gel coupled with p-aminobenzamidine. 393 3

Human tissue factor pathway inhibitor-2 (TFPI-2)/matrix-associated serine protease inhibitor (MSPI), a Kunitz-type serine protease inhibitor, inhibits plasmin, trypsin, chymotrypsin, plasma kallikrein, cathepsin G, and factor VIIa-tissue factor complex. The mature protein has a molecular mass of 32-33 kDa, but exists in vivo as two smaller, underglycosylated species of 31 and 27 kDa. TFPI-2/MSPI triplet is synthesized and secreted by a variety of cell types that include epithelial, endothelial, and mesenchymal cells. Because the majority (75-90%) of TFPI-2/MSPI is associated with the extracellular matrix (ECM), we examined which components of the ECM bind TFPI-2/MSPI. We found that TFPI-2/MSPI bound specifically to heparin and dermatan sulfate. Interaction of these two glycosaminoglycans (GAGs) with TFPI-2/MSPI involved one or more common protein domains, as evidenced by cross-competition experiments. However, binding affinity for TFPI-2/MSPI with heparin was 250-300 times greater than that for TFPI-2/MSPI with dermatan sulfate. Binding of TFPI-2/MSPI to GAGs was inhibited by NaCl or arginine but not by glucose, mannose, galactose, 6-aminohexanoic acid, or urea, suggesting that arginine-mediated ionic interactions participate in the GAG binding of TFPI-2/MSPI. This supposition was supported by the observation that only NaCl or arginine could elute the TFPI-2/MSPI protein triplet from an ECM derived from human dermal fibroblasts. Reduced TFPI-2/MSPI did not bind to heparin, suggesting that proper disulfide pairings and conformation are essential for matrix binding. To determine whether heparin modulates the activity of TFPI-2/MSPI, we determined the rate of inhibition of plasmin by the inhibitor with and without heparin and found that TFPI-2/MSPI is more active in the presence of heparin. Collectively, our results demonstrate that conformation-dependent arginine-mediated ionic interactions are responsible for the TFPI-2/MSPI triplet binding to fibroblast ECM, heparin, and dermatan sulfate and that heparin augmented the rate of inhibition of plasmin by TFPI-2/MSPI.
 ...
PMID:Matrix localization of tissue factor pathway inhibitor-2/matrix-associated serine protease inhibitor (TFPI-2/MSPI) involves arginine-mediated ionic interactions with heparin and dermatan sulfate: heparin accelerates the activity of TFPI-2/MSPI toward plasmin. 1049 84

This study reports the isolation and partial characterisation of the ostrich serpin, alpha(2)AP, and its target enzyme, ostrich plasmin, in its active and inactive proenzyme, namely plasminogen, forms. Ostrich alpha(2)AP was purified using L-lysine-Sepharose chromatography, ammonium sulfate fractionation, and Super Q-650S and ostrich LBSI-Sepharose chromatographies. It revealed a M(r) of 84 K (thousand) and had one and two N-terminal amino acids in common with 11 of those of human and bovine alpha(2)AP, respectively. It showed the largest inhibitory effect on ostrich plasmin, followed by bovine trypsin and plasmin, respectively, and much less plasmin inhibition than bovine aprotinin, but much more so than human alpha(2)AP, DFP and EACA. Ostrich plasminogen was highly purified after L-lysine-Sepharose chromatography and showed a M(r) of 92 K, a total of 775 amino acids and its N-terminal sequence showed approximately 53% identity with those of human, rabbit, cat, and ox plasminogens. Ostrich plasmin, obtained by the urokinase-activation of ostrich plasminogen, revealed a M(r) of 78 K, a total of 638 amino acids, an N-terminal sequence showing two to four residues identical to five of those of human, cat, dog, rabbit, and ox plasmins, and pH and temperature optima of 8.0 and 40 degrees C, respectively.
 ...
PMID:Purification and partial characterisation of alpha(2)-antiplasmin and plasmin(ogen) from ostrich plasma. 1143 35

At the time of sperm-egg fusion in Discoglossus pictus, a large amount of electron-dense material of an unknown nature is liberated from the sperm. In the present work we studied this material in D. pictus sperm, using an assay utilising strips of autoradiographic film as a gelatin substrate for proteolytic enzymes. Upon treatment with A23187, D. pictus sperm produced a large halo on the gelatin substrate, indicating the presence of enzymes released by the sperm at the time of the acrosome reaction. In contrast, Xenopus laevis sperm did not produce halos upon treatment with A23187. The use of protease inhibitors such as TLCK, leupeptin, chymostatin, SBTI and EACA strongly suggests that the D. pictus whole acrosome contains trypsin and chymotrypsin activity while an SBTI-sensitive activity is absent in a small portion of the acrosome, possibly the anteriormost region. Furthermore, the material released at the acrosome reaction also contains an EACA-inhibited activity, indicating the presence of plasminogen activator. We conclude that D. pictus sperm release proteolytic enzyme(s) that may act at the egg surface at the time of gamete fusion.
 ...
PMID:Enzyme activity in anuran spermatozoa upon induction of the acrosome reaction. 1177 95


1 2 3 4 5 6 7 8 9 Next >>