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)

Kininogen level, that of active kinins and kininase activity in the plasma of patients suffering from cirrhosis of the liver and of healthy people were studied. The kininogen content was determined by different available methods i.e. the trypsin and acetone techniques and by means of the plasma and glandular kallikrein preparation. An increase in kininase activity and a lowered kininogen level as determined by all the methods were found in the sick persons. The maximal decrease in the kininogen level determined by means of the plasma kallikreins is substantiated in connection with the increased fibrinolytic activity of the plasma of the patients with hepatic cirrhosis.
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PMID:Studies of the plasma kinin-forming system in cirrhosis of the liver. 16 51

A pancreatic endopeptidase localized to the beta-cells of the pancreas by immunohistochemical techniques has been purified to homogeneity by following its functional and antigenic characteristics as a glandular kallikrein (EC 3.4.21.8). The enzyme gave a single stained band on alkaline disc gel electrophoresis which corresponded in location with the kinin-generating activity eluted from a replicate gel, was of 54,000 molecular weight by gel filtration, was devoid of caseinolytic activity, elicited a monospecific antiserum in a rabbit, and gave a line of complete identity with a single constituent in pancreatic extract, crude urine, and purified urokallikrein when analyzed with monospecific antibody to urokallikrein. The pancreatic glandular kallikrein generated three cleavage products of increasing anodal mobility from bovine and porcine proinsulin, and the presence of pancreatic kininase or bovine carboxypeptidase B increased the quantity of these products. Although the conversion products did not correspond to diarginyl- and monoarginylinsulin, the product of intermediate mobility was also obtained when proinsulin was treated with a low concentration of trypsin in the presence of kininase. The most rapidly migrating product did correspond to desalanylinsulin in the reference standard. Kininase alone had no action on proinsulin, and aprotinin prevented cleavage by kallikrein alone or in combination with kininase. Although the chemical structure of the proinsulin cleavage products has not been established, human pancreatic kallikrein is considered a putative activator of proinsulin because of its location in the beta-cell, its preferential action on proinsulin and kininogen as compared to azocasein, and its capacity to generate insulin intermediate products that are further modified by human pancreatic kininase or bovine carboxypeptidase B.
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PMID:Sequential cleavage of proinsulin by human pancreatic kallikrein and a human pancreatic kininase. 38 42

From rat stomach, kallikrein was purified by chromatographies on columns of p-aminobenzamidine-Sepharose, DEAE-Sephadex A-50 and Sephadex G-150 and by isoelectric focusing, measuring its activities to hydrolyse prolylphenylalanyl-arginine-4-methyl-coumarine amide (Pro-Phe-Arg-MCA) and to release kinin from rat heated-plasma. The purified stomach kallikrein showed a single band on Disc electrophoresis at pH 7.0. The molecular weight of the kallikrein was calculated to be 29,000 by gel-filtration on a column of Sephadex G-50. The kallikrein was stable between pH 6 and 11 and hydrolysed Pro-Phe-Arg-MCA optimally at pH 11.0. The Pro-Phe-Arg-MCA hydrolysing activity of rat stomach kallikrein was inhibited by DFP and Trasylol, but not by trypsin inhibitors from soyabean, limabean and ovomucoid. These properties of rat stomach kallikrein was clearly distinguishable from those of partially purified rat plasma kallikrein, but similar properties to other glandular kallikreins from other species. From these results, it was concluded that kallikrein is present in rat stomach, which can be classified into glandular kallikrein.
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PMID:Rat stomach kallikrein: its purification and properties. 49 18

Besides guanidino compounds and amines structurally related to arginine and lysine, compounds with other cationic groups are inhibitors of trypsin-like serine proteinases. Particularly aromatic ring structures with an amidino moiety have high affinity for these enzymes. In most cases ordinary benzamidine derivatives are no selective inhibitors, however, among derivatives of N alpha-arylsulfonyl-omega-amidinophenyl-alpha-amino-alkylcarboxylic acids selective competitive inhibitors of several enzymes were found. Amides of phenyl-alpha-aminobutyric acid containing an amidino moiety are inhibitors of plasma kallikrein. The p-amidinoanilide of 2-tosylamino-4-phenylbutyric acid inhibits selectively plasma kallikrein with a Ki of 0.70 mumol/l. In contrast, potent and selective inhibitors of glandular kallikrein were hardly found among benzamidines.
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PMID:Inhibition of glandular and plasma kallikrein by benzamidine derivatives. 146 70

Prostate-specific antigen (PSA) is one of the three most abundant prostatic-secreted proteins in human semen. It is a serine proteinase that, in its primary structure, manifests extensive similarities with that of the Arg-restricted glandular kallikrein-like proteinases. When isolated from semen by the addition of chromatography on aprotinin-Sepharose to a previously described procedure, PSA displayed chymotrypsin-like activity and cleaved semenogelin and the semenogelin-related proteins in a rapid and characteristic pattern, but had no trypsin-like activity. About one third of the purified protein was found to be enzymatically inactive, due to cleavage carboxy-terminal of Lys145. Active PSA formed SDS-stable complexes with alpha 1-antichymotrypsin, alpha 2-macroglobulin-analogue pregnancy zone protein. PSA formed inhibitory complexes with alpha 1-antichymotrypsin at a molar ratio of 1:1, a reaction in which PSA cleaved the inhibitor in a position identical to that reported from the reaction between chymotrypsin and alpha 1-antichymotrypsin. The formation of stable complexes between PSA and alpha 1-antichymotrypsin occurred at a much slower rate than that between chymotrypsin and alpha 1-antichymotrypsin, and at a similar or slightly slower rate than that between PSA and alpha 2-macroglobulin. When added to normal blood plasma in vitro, active PSA formed stable complexes both with alpha 2-macroglobulin and alpha 1-antichymotrypsin. This complex formation may be a crucial determinant of the turnover of active PSA in intercellular fluid or blood plasma in vivo.
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PMID:Enzymatic activity of prostate-specific antigen and its reactions with extracellular serine proteinase inhibitors. 170 14

PSA is a 34-kd 240-amino acid glycoprotein produced by the prostatic epithelial cells. It is a member of the glandular kallikrein gene family and has a high sequence homology with human glandular kallikrein (hGK-1). PSA is a serine protease and has chymotrypsin-, trypsin-, and esterase-like activities. It is secreted into the seminal fluid where it degrades two seminal vesicle proteins that are important components of the semen coagulum, thus playing an important role in semen liquefaction. The production of PSA protein appears to be under the control of circulating androgens acting through the androgen receptor. Therefore, the significance of a low serum PSA value in a patient who has undergone previous antiandrogen therapy may not be the same as that for a patient who has not received endocrine treatment.
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PMID:Prostate-specific antigen and prostatic acid phosphatase: biomolecular and physiologic characteristics. 171 6

In this study we investigated the effects of steroid hormones on glandular kallikrein gene expression in the rat pancreatic acinar cell line AR42J. Using a cloned complementary DNA probe and a polyclonal antibody we demonstrated expression of a true glandular kallikrein gene and protein in AR42J cells by Western and Northern blot analysis. Dexamethasone resulted in a time-dependent parallel decrease of kallikrein messenger RNA and protein with a maximum at 12 and 72 h (30 +/- 10 and 8 +/- 0.5% of control, respectively, P less than 0.05, n = 6). In contrast, dexamethasone stimulated gene expression of two other serine proteases, chymotrypsin and trypsin, approximately 3 to 4-fold. The decrease of kallikrein concentration was dose dependent with half-maximal effects at 5 x 10(-8) M and maximal effects at 10(-7) M dexamethasone (23 +/- 6% of control, n = 3). The glucocorticoid antagonist RU 38486 blocked the glucocorticoid-induced decrease in cellular kallikrein content in a dose-dependent manner. Complete inhibition was observed at equimolar doses of dexamethasone and the antagonist. The inhibitory effect of dexamethasone was completely reversible after hormone withdrawal for 24 h. Neither estrogen, progesterone, testosterone, or aldosterone had significant effects on kallikrein expression. These data suggest that down-regulation of pancreatic kallikrein gene expression occurs selectively in response to glucocorticoids at a pretranslational level, mediated most likely by the glucocorticoid receptor.
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PMID:Glandular kallikrein gene expression is selectively down-regulated by glucocorticoids in pancreatic AR42J cells. 201 48

Evidence for a kallikrein-kinin system (KKS) in fish is incomplete. In the present study, components of the KKS were identified in rainbow trout. Tissues were assayed for kallikrein-like esterolytic activity using three synthetic kallikrein substrates (TAME, VGAN, and PPAN), and the presence of kallikrein substrate (kininogen) in trout plasma was estimated by bradykinin (BK) radioimmunoassay of plasma activated with trypsin (T). Formation of pressor-depressor substances in vivo by porcine glandular kallikrein (GK) and T was measured after intra-arterial injection into unanesthetized trout. Gill and kidney contained kallikrein activity (TAME and VGAN assays); little activity was observed with PPAN. Aprotinin inhibited gill activity (TAME assay). T liberated 42 +/- 3 (SE) ng (n = 10) of immunoreactive BK per milliliter of plasma. Injection of GK in vivo reduced plasma kininogen levels for over 24 h. GK produced pressor responses only in fish pretreated with the angiotensin-converting enzyme (ACE) inhibitor captopril. This effect was mediated partly through stimulation of alpha-adrenergic receptors. T produced slight pressor responses that were captopril insensitive. These results show that trout possess elements of the KKS system including kallikrein-like enzymatic activity, kininogen, receptor-mediated vascular sensitivity to kallikrein products, and kininolytic activity consistent with ACE (kininase II).
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PMID:Enzymes of the kallikrein-kinin system in rainbow trout. 217 52

We have studied rat vascular smooth muscle (VSM) cells in culture for the presence of key elements of the glandular kallikrein-kinin system. Direct radioimmunoassay (RIA) using antiserum against rat urinary kallikrein detected a glandular kallikrein-like enzyme (GKLE) in VSM cells and in media. VSM homogenates and culture media had kininogenase activity, generating kinins from dog kininogen. About half of the GKLE was enzymatically inactive which could be activated with trypsin. Kininogenase activity was inhibited completely by aprotinin but only 20% by soybean trypsin inhibitor (SBTI). Trypsin liberated kinins from homogenates and media, demonstrating that VSM cells contain kininogen. Homogenates and media rapidly degrade bradykinin. GKLE, kininogen, and bradykininase activity were all present in VSM cells grown in defined media that contain no serum, thus eliminating any contamination or artefacts from fetal calf serum in standard culture media. Blood vessels of the rat have been reported to contain GKLE. Our observations indicate that GKLE is synthesized by VSM cells, not deposited from plasma. Furthermore, VSM cells synthesize kininogen and bradykininase(s), the other key elements of the glandular kallikrein-kinin system. Thus it is possible that the system functions as an autocoid mechanism that regulates local vascular tone.
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PMID:Rat aortic smooth muscle cells in culture express kallikrein, kininogen, and bradykininase activity. 229 24

Various factors in the kallikrein-kinin system were evaluated in acute and chronic pancreatitis. It was noted in particular that plasma trypsin and glandular kallikrein increased markedly in acute phase of pancreatitis and its correlation with amylase was observed. Plasma prekallikrein (PPK) decreased in acute pancreatitis, but increased in chronic pancreatitis. A negative correlation was noted between PPK and kallikrein like activity. Both HMW and LMW kininogen decreased in acute pancreatitis. It was presumed from these findings that the increase in kinin and its activation at the acute phase of pancreatitis might be due to kallikrein or trypsin originating from the pancreas.
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PMID:Role of the kallikrein-kinin system in human pancreatitis. 248 54


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