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)

Highly purified kininogen preparation with the activity of 16-18 int. units per mg was isolated from rabbit blood serum. Its molecular weight was estimated to be 54 000 by gel filtration through Sephadex G-200. Leucine was identified as N-terminal amino acid by the dansylation method. Rabbit kininogen consists of 394 amino acid residues (except tryptophane). Amino acid composition of kininogen is characterized by a high content of dicarbonic amino acids, proline and by a low content of methionine. Kininogen molecule does not contain SH-groups. 13.1-13.5 SH-groups were found in kininogen after the reduction of S-S bonds with beta-mercaptoethanol in the presence of 8 M urea, thus indicating the presence of 6-7 S-S bonds in kininogen molecule. Kininogen group does not occupy C-terminal position in the molecule, because the treatment of the protein with carboxypeptidase B does not change the content of bradykinine in it. Purified kininogen preparation is a substrate for kallikrein from rabbit blood plasma, human saliva and trypsin. Unlike trypsin, kallikreines from human blood plasma and saliva release kinines from kininogen with reduced S-S bonds. Under spontaneous reoxidation of reduced S-S bonds up to 90%, substate properties of kininogen for tripsin recover only by 50%. Rabbit kininogen is similar to beef kininogen II in its molecular weight, amino acid composition and the number of S-S bonds.
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PMID:[Amino acid makeup, structural characteristics and substrate specificity of rabbit plasma kininogen]. 113 95

1 Prostaglandins E1 and E2 but not prostaglandin F2alpha, arachidonic acid or linolenic acid, produced slight oedema when injected into the rat hindpaw. 2 Prostaglandin E1 potentiated hindpaw oedema produced by carrageenan, kaolin, bradykinin and trypsin but not that produced by 5-hydroxytryptamine (5-HT), histamine, dextran B or compound 48/80. Carrageenan- and bradykinin-induced paw oedemas were also potentiated by prostaglandin E2. Arachidonic acid potentiated responses to carrageenan and kaolin but not responses to bradykinin, trypsin, 5-HT, histamine, dextran B or compound 48/80. Linolenic acid did not potentiate hindpaw oedema induced by carrageenan. 3 Potentiation of carrageenan-induced oedema by prostaglandin E1 was not diminished by pretreatment with indomethacin, hydrocortisone or cyproheptadine. However, arachidonic acid potentiation of carrageenan oedema was reduced by pretreatment with non-steroidal anti-inflammatory drugs but not by anti-inflammatory steroids or by paracetamol. 4 The enhancement of the response to carrageenan and kaolin by prostaglandins E1, E2 and arachidonic acid is discussed in terms of kinin mediation.
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PMID:On the ability of prostaglandin E1, and arachidonic acid to modulate experimentally induced oedema in the rat paw. 118 49

A rat preparation in which the perfusion route bypassed the lungs, which were substituted by an artificial oxygenator, was exsanguinated and perfused with oxygenated 4% dextran (M.W. 70,000) in Tyrode's fluid; a peristaltic pump propelled the perfusing fluid at 20-25 ml/min through the aortic arch and the perfusion medium returned to the right ventricle. Known amounts of bradykinin (BK), kallidin (lysul-bradykinin, LBK) and methionyllysylbradykinin (MLBK) were administered as single injections and samples of the perfusion fluid removed between 1.5 to 6 min following injection. Average total kinin activity remaining in the circulating fluid was calculated from assays on the isolated guinea pig ileum against respective kinin injected and found to be after 3 and 6 min respectively: 20 and 5% for BK, 54 and 21% for LBK, 60 and 30% for MLBK. When the lungs were introduced in the perfusion circuit BK recoveries decreased to 0.4% at 4 min and 0% at 6 min. In 2 experiments 1 mg MLBK and, in another two, 1 mg of LBK were recirculated for 3 to 3.5 min in the rat preparation with lung bypass; enzymic reactions were interrupted in the perfusates after removal by lowering the pH to 4.7 and placing them in a boiling water bath for 5 min. Following proper dilution, kinin activity left in the perfusates was separated on carboxymethylcellulose columns; in 3 experiments about 50% of the activity was identified as BK from its elution position and resistance to trypsin digestion. The average BK-inactivating potency of the perfusate obtained from the rat with lung bypass was 0.3 mug BK/min x ml compared to 16 mug BK/min x ml of rat plasma. The arylamidase activity on arginylnaphthylamide of the perfusate was 2 n moles NA/min x ml and it was about 25-fold lower than that of rat plasma. Rat liver was exsanguinated and perfused in situ through the portal vein and inferior cava vein using the same conditions as for the whole animal. The perfusion rate was 12 ml/min. The recovery of injected BK in this preparation was 40% after 2 min of recirculation, declining progressively in the following minutes. When MLBK was perfused in this preparation for 3 min or glycylarginyllysylbradykinin (GALBK) for 3 and 5 min, significant amounts of BK were found in the perfusates. We conclude that LBK, MLBK and GALBK may be converted at a high rate into BK by tissue aminopeptidases found in the rat preparations used. BK inactivation in the whole rat is a fast reaction, even when the pulmonary tissue is not involved in the inactivation.
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PMID:Recovery and conversion of kinins in exsanguinated rat preparations. 118 19

Trypsin, when incubated with human plasma protein either undenatured or denatured by pretreatment with acid or alkali or by heat, produced an angiotensin II-like pressor substance instead of the depressor bradykinin which has been reported to be formed from various plasma fractions and trypsin. This reaction may be due to the activation of prorenin by trypsin, but this is rather unlikely since it appears that angiotensin II rather than I is formed. It seems to be more likely a direct production of the angiotensin hormone from the substrate, and we propose to call tentatively the active product "tryptensin".
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PMID:A pressor formation by trypsin from renin-denatured human plasma protein. 125 98

To study the degree of protease activation at reperfusion of a pancreatic allograft after cold storage for 24 hr, 18 porcine whole-organ pancreaticoduodenal allograft transplantations were performed. Twelve grafts were flushed with and stored in Perfadex. In six of these, a hyperosmotic salt solution was injected into the graft aorta at reperfusion. Six grafts were flushed and stored in UW solution. Eleven of twelve grafts in the Perfadex groups were functioning on the first postoperative day, compared with one of six in the UW solution group. There was a significantly more pronounced protease activation among grafts stored in UW solution than in the other groups, with a subsequent breakthrough of the local protease protection barrier made up of protease inhibitors. In surviving pigs (n = 14), biochemical signs of protease activation evolved in plasma, including formation of trypsin-protease inhibitor complexes, a decline in C3 and kininogen levels, and a decline in functionally active alpha 2-macroglobulin, functionally active antithrombin III, and plasma kallikrein inhibitory activity. These biochemical signs of pancreatitis correlated with a deteriorated graft function on the second postoperative day, indicating that graft tissue damage occurred due to protease activation.
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PMID:Protease activation following reperfusion of porcine pancreatic allografts. 127 75

In order to elucidate the analgesic mechanism of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614), its effects on the kinin-forming system were examined both in vivo and in vitro. T-614, at doses more than 10 mg/kg p.o., exhibited a significant inhibitory effect on the increased levels of bradykinin released into the pouch fluid of kaolin-induced inflammation in rats. In the kaolin-induced writhing response in mice, which is shown to be mainly dependent on the action of bradykinin, T-614 reduced not only the writhing frequency but also the peritoneal levels of bradykinin in a dose-dependent manner. Whereas, in the zymosan-induced writhing response in which prostaglandin I2 (PGI2) is shown to be an important mediator, it did not exert an obvious inhibition on either writhing responses or peritoneal PGI2 levels at a highest dose of 100 mg/kg. T-614 did not inhibit the activities of serine proteases, such as trypsin, thrombin, kallikrein and plasmin. Furthermore, it did not affect the kinin-forming enzymes of rat plasma in vitro. The above results suggest that the analgesic effects of T-614 may be partly mediated by the inhibition of bradykinin release in the local inflamed tissue.
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PMID:Pharmacological studies on 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one (T-614), a novel antiinflammatory agent. 3rd communication: the involvement of bradykinin in its analgesic actions. 128 99

This paper details the methods of establishing stock culture and subculture of calf and pig aorta endothelial cells and the effects of bradykinin, ionophore A23187, trypsin and arachidonic acid (AA) on the release of prostacyclin (PGI2) from the cells. The release was measured by 6-keto PGF1 alpha radioimmunoassay. The results showed that the stimuli significantly increased the release of PGI2 in the two endothelial cell types (P < 0.01, n = 8), and the release was much stronger in pig than in calf endothelial cells under the experimental conditions. We therefore suggest that the reactivities of the two endothelial cells to the stimuli differ. The results offer useful information for further research of the mechanism of their pharmacologic actions on endothelial cells and their relationship with PGI2.
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PMID:[Effect of bradykinin, ionophore A23187 and trypsin on prostacyclin release from calf and pig aorta endothelial cells]. 129 38

A proteolytic enzyme from L. muta stenophrys was isolated by gel filtration on Bio Gel P-100 followed by FPLC on MONO S column. The enzyme exhibited proteolytic activity toward casein, hemoglobin and fibrinogen with a pH optimum around 10. The activity was inhibited by EDTA while trypsin inhibitors were not inhibitory. It is a glycoprotein, Mr 14 kDa with a high content of Asp, Glu, and Leu residues and a low content of Cys and Trp. The protease is devoid of myotoxic, hemorrhagic, esterolytic and amidolytic activities. It lyses the alfa and beta chains of human fibrinogen and releases kinin from L.M.W. kininogen. No release of histamine was observed upon incubation with mast cells.
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PMID:Characterization of a proteolytic enzyme from Lachesis muta venom (Serpentes: Viperidae). 130 16

Angiotensin I(AI)-converting enzyme (ACE) (EC 3.4.15.1) was solubilized from the membrane fraction of chicken lung using trypsin and nonidet P40 extraction, and then purified to homogeneity by captopril affinity chromatography. Comparison of trypsin-extracted and detergent-solubilized membrane-bound converting enzyme by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and isoelectric focusing indicated that the membrane-binding sequence contributed to a large extent to the size and charge of the enzyme. Both forms of the enzyme were glycoproteins but they differed in the glucidic content; 4.5% by weight of the enzyme in the trypsin-extracted ACE and 15% by weight of the enzyme in the detergent-solubilized ACE. In both cases hexoses were the most abundant residues. Both forms of the enzyme were found to contain 1 g-atom zinc/mol enzyme. The purified enzymes did not only split Hip-His-Leu but also AI and bradykinin. The Michaelis constant (Km) and maximum velocity (Vmax) values of the trypsin-extracted ACE for Hip-His-Leu were 52 x 10(-5) mol/l and 15.36 nmol/min respectively, and for AI they were 7.8 x 10(-5) mol/l and 0.45 nmol/min respectively. The Km and Vmax values of the detergent-solubilized ACE for Hip-His-Leu were 32 x 10(-5) mol/l and 11.75 nmol/min respectively, and for AI they were 6.5 x 10(-5) mol/l and 0.97 nmol/min.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of chicken lung angiotensin I-converting enzyme. 131 47

Specific HKg immunostaining detected with antiserum against the light chain (LC) of HKg was restricted to SRIF neurons of the hypothalamic periventricular area projecting to median eminence (ME). Heavy chain (HC) immunoreactivity related to HKg and/or low molecular weight kininogen (LKg) was found in some other hypothalamic territories. Specific TKg was mainly associated with vasopressin in neurons of suprachiasmatic (SCN), supraoptic (SON) and paraventricular (PVN) nuclei. By direct RIA, hypothalamus was found to contain the highest level of TKg (10ng/mg protein) and after trypsin hydrolysis and HPLC separation of kinins, 10.3 pg BK and 7.3 pg T-kinin/mg protein.
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PMID:Immunolocalization of high molecular weight kininogen (HKg) and T kininogen (TKg) in the rat hypothalamus. 136 1


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