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)

Immunoreactive pancreatic secretory trypsin inhibitor (PSTI) was purified to homogeneity from human gastric mucosa by gel chromatography, ion-exchange chromatography, and repeated reverse-phase high-performance liquid chromatography (HPLC). The molecular weight of the purified immunoreactive PSTI in human gastric mucosa was estimated to be 6000. The electrophoretical mobility of purified PSTI was identical with that of the main component of PSTI in human pancreatic juice. It consisted of 56 amino acids and had the same amino acid composition as PSTI in pancreatic juice. It inhibited bovine pancreatic trypsin stoichiometrically, and did not inhibit porcine pancreatic kallikrein or elastase. Heat treatment of immunoreactive PSTI in gastric mucosa showed the same inactivation curve of immunoreactivity as that of pancreatic juice PSTI.
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PMID:Purification and characterization of pancreatic secretory trypsin inhibitor in human gastric mucosa. 363 92

Kallikrein inhibiting proteins with two different molecular weight (6-8 X 10(4), 8-9 X 10(4) respectively) were observed in adrenalectomized rat kidney cortical soluble fraction. The larger one was observed in the kidneys of the adrenalectomized rats only when they had received chronic administration of excess amount of dexamethasone, and its kallikrein inhibitory activity was not lost with treatment with trypsin. This protein appears to be induced by chronic administration of glucocorticoid and might participate in the process of glucocorticoid regulating renal kallikrein kinin system.
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PMID:Endogenous kallikrein inhibitor in rat kidney cortex-effect of glucocorticoid administration. 364 17

The method of measurement for urinary total kallikrein (KAL) and preKAL in human was developed, and daily excretions of urinary total KAL, KAL and preKAL were investigated in patients with essential hypertension. Forty microliter of urine samples were incubated with or without 120 micrograms of chymotrypsin-free trypsin for total KAL or KAL, respectively. KAL was measured with direct radioimmunoassay and kininogenase assay. PreKAL was calculated by the subtraction of KAL from total KAL. The subjects of this study included 7 normotensives (NT) and 8 essential hypertensives (EHT). Daily excretions of total KAL, KAL and preKAL were significantly lower in EHT than those in NT. KAL/total KAL ratio, which reflects the conversion rate from preKAL to KAL in the kidney, was not significantly different between EHT and NT. From these results, it is suggested that decreased urinary KAL excretion in EHT is mainly caused by reduced preKAL production rather than the impaired conversion from preKAL to KAL in the kidney. It is emphasized that this method of measurement for urinary total KAL and preKAL may be a very useful tool for research of the renal kallikrein-kinin system.
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PMID:The method of urinary total kallikrein and prekallikrein measurement, and their urinary excretions in the patients with essential hypertension. 364 31

Rat urinary kallikrein (RUK) was purified to apparent homogeneity by a three-step procedure and antibodies were raised in rabbits. Renal kallikrein exists as an active and an inactive form. A specific radioimmunoassay (RIA) was developed to measure directly the total kallikrein. The antibody used in this radioimmunoassay recognized both forms. No cross reactivity was detected with trypsin, esterase A or human urine. When iodinated rat urinary kallikrein was used, the detection range was between 0.125 and 16 ng with 6.5% intraassay variation and 8.1% between assay variation. Intrarenal kallikrein was measured in renal tissue after homogeneisation and solubilisation. Correlations between this RIA and the kininogenase activity or the amidolytic activity were highly significant. Since kallikrein exists as an inactive precursor the direct measurement of the total immunoreactive protein differs from activities determinations. An HPLC ion exchange system has been developed to separate active and inactive forms directly from urine, with a recovery of 79 +/- 11%. This procedure permits measurement of inactive forms. Rat urine contains as much inactive kallikrein as active kallikrein.
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PMID:Direct radioimmunoassay of rat urinary kallikrein: its application to the determination of active and inactive kallikrein concentration after HPLC analysis. 364 25

Hydrolyses catalyzed by bovine pancreatic trypsin and porcine pancreatic kallikrein were studied using synthetic peptide substrates of the type E chi-L chi 2-L chi 1 decreases Y and E chi-L chi 3-L chi 2-L chi 1 decreases Y with L chi 1 = Arg defining the hydrolysis position (indicated by the arrow). The leaving moiety Y was -OCH3, -NH-C6H4-p-NO2 and -Ala-NH2. Insight into interactions occurring between the active site of the enzymes and the acyl moiety of the substrates was gained by studying the influence on hydrolysis rate of structural variation of residues L chi 2 and L chi 3. Parallel analyses of the hydrolyses of the ester, anilide, and peptide substrates having the same acyl moiety considerably facilitated the interpretation of the kinetic data. Trypsin, but not kallikrein, displayed high reactivity even with relatively short substrates. Ac-Ala-Arg-Ala-NH2, for example, was a better substrate for trypsin than for kallikrein by a factor of 1.3 X 10(4) in terms of kcat and 5.9 X 10(4) in terms of kcat/Km. Reactivity differences of such magnitude were related to two main differences in enzyme-substrate interactions: the interaction of the arginine side chain of the substrate with the specificity pocket of the enzyme is optimal for trypsin but poor for kallikrein and the number of hydrogen bonds formed by the enzyme with the backbone section of the substrate on both sides of the specific residue is larger in the case of trypsin. The latter difference is found to be related to the structure of amino-acid residue 192 which is glutamine in trypsin and methionine in kallikrein.
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PMID:Comparative specificity of porcine pancreatic kallikrein and bovine pancreatic trypsin. Importance of interactions N-terminal to the scissible bond. 365 53

Most previous studies have not significantly correlated urinary kallikrein to urinary kinins. We investigated whether urinary kininogen might influence kinin formation within the urine. On an ad-lib diet the 24 hour excretion of total and intact kininogen, kinins and kallikrein was determined in 24 control subjects, 20 untreated essential hypertensives, 12 with end-stage renal disease and 8 subjects with liver disease. Kallikrein and kinins were measured by a direct radioimmunoassay. Total kininogen was determined from the sum of preformed kinins and kinins generated after trypsin (intact kininogen). Cross reactivity between purified human low molecular weight kininogen and bradykinin antiserum was 3%. Total and intact kininogen were significantly correlated with kinins in controls, essential hypertension and liver disease. In essential hypertension, end-stage renal and liver diseases kinins were significantly decreased. This was associated with a reduction in kininogen but not kallikrein in essential hypertension and liver disease, and a reduction in kallikrein but not kininogen in end-stage renal disease. Thus, renal kinin generation in various states may be affected by either or both kininogen and kallikrein.
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PMID:Urinary kininogen: a possible regulator of kinin formation in normal individuals and subjects with essential hypertension, end-stage renal and liver disease. 381 87

To assess possible interactions of circulating vasopressin with the synthesis or activation of renal kallikrein, we studied the effect of chronic infusion of vasopressin (7.2 U/kg/day i.p.) for 6 days on the urinary excretion of total and active kallikrein in conscious rats. We determined urinary total, active and inactive kallikrein by measuring kallikrein activity using a kininogenase assay before and after the treatment with trypsin (200 micrograms/ml). Chronic infusion of vasopressin induced sustained decreases in urinary total, active and inactive kallikrein excretion, but did not affect the ratio of active to total kallikrein. The infusion of vasopressin induced significant increases in circulating levels of vasopressin (248.1 +/- 35.2 pg/ml in vasopressin-infused rats (n = 7) compared to 95.5 +/- 14.6 pg/ml in vehicle-infused rats (n = 7), p less than 0.001) and in weight gain (39.6 +/- 1.3 g in vasopressin-infused rats (n = 7) compared to 29.1 +/- 3.3 g in vehicle-infused rats (n = 7), p less than 0.05), and also sustained decreases in water intake and urine volume, but it did not induce any change in urinary sodium excretion. Circulating levels of angiotensin II was decreased by chronic infusion of vasopressin. Thus, the present study suggests that the elevation of circulating vasopressin levels induces a decrease in the synthesis of renal kallikrein.
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PMID:Decreased urinary active and inactive kallikrein by chronic infusion of vasopressin in conscious rats. 384 7

A series of acetyl-peptidyl-amides containing the amino acid sequence around the Arg-Ser kallikrein cleavage site of bovine kininogen were synthesized and tested for their ability to inhibit both the kinin-releasing activity and the amidase activity of purified human urinary kallikrein. The substrate analogues were competitive inhibitors for human urinary kallikrein and the heptapeptides (P4-P3'), hexapeptides (P3-P3'), and pentapeptides (P2-P3') gave Ki values of 140, 64, and 18 microM respectively, while the tetrapeptides (P1-P3'), tripeptides (P1'-P3') and dipeptides (P2'-P3') had little or no inhibitory activity. The effective analogues had neither kinin-like nor kinin-blocking activity on the rat uterus either before or after exposure to human urinary kallikrein. The effective human urinary kallikrein inhibitors were further examined for their effect on other serine proteases, including human plasma kallikrein, plasmin, complement components (C1s, C1r), bovine coagulation factors (IIa, IXa, and Xa), elastase, and trypsin. These peptides showed little inhibition of the circulating serine proteases but yielded a Ki for the nonspecific protease trypsin in the microM range. These results should provide the basis for the development of highly specific tissue kallikrein inhibitors to aid in elucidating the in vivo role(s) of tissue kallikreins.
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PMID:Specificity of substrate analogue inhibitors of human urinary kallikrein. 384 67

Kinin release in Brown Norway Katholiek (B/N-Ka) rat plasma was compared with those of Brown Norway Kitasato and Sprague-Dawley rats by treating with rat plasma kallikrein, rat urinary kallikrein, snake venom kininogenase and trypsin. B/N-Ka rat plasma yielded no detectable amount of kinin by either plasma kallikrein, urinary kallikrein or snake venom kininogenase, but yielded variable amount of kinin by trypsin. The released kinin was proved to be isoleucylseryl-bradykinin by high performance liquid chromatography and bioassay profiles. B/N-Ka rat plasma formed a precipitation line against antiserum to T-kininogen, but no line against antiserum to HMW kininogen-light chain.
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PMID:Identification of T-kininogen in high and low molecular weight kininogens deficient rat (brown Norway Katholiek strain). 385 Jun 46

Ethyl esters of N-(3- and N-(4-amidinobenzoyl)(-L-)amino acids (namely, glycine, alanine, valine, leucine and phenylalanine) were synthesized and their inhibitory effect on the bovine trypsin and porcine pancreatic kallikrein catalyzed hydrolysis of p-nitroanilides of amino acids was investigated, at pH 8.1 and 37 degrees, in parallel with the effect of ethyl and/or methyl esters of N-benzoyl(-L-)amino acids and benzamidine. For both proteinases, the inhibitory effect of ethyl esters of N-(3- and N-(4-amidinobenzoyl)(-L-)amino acids is independent of the aminoacidic side chain, is closely similar to that of benzamidine (which binds at the S1 subsite of the proteinases examined and is commonly taken as a molecular inhibitor-model), and is higher by at least 10-fold than that of ethyl and/or methyl esters of N-benzoyl(-L-)amino acids (depending on the aminoacidic residue). On structural grounds, the peculiar inhibitory behaviour of ethyl esters of N-(3- and N-(4-amidinobenzoyl)(-L-)amino acids has been related to the interaction of the positively charged substituent at the N-position with the Asp189 residue present in the primary specificity subsite (S1) of bovine trypsin and porcine pancreatic kallikrein. The consistently lower affinity for porcine pancreatic kallikrein of all the inhibitors considered, as compared to bovine trypsin, may be related to the marked structural differences of the primary specificity subsite of these two serine proteinases.
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PMID:Ethyl esters of N-(3- and N-(4-amidinobenzoyl)(-L-)amino acids: synthesis and antiproteolytic activity towards bovine trypsin and porcine pancreatic kallikrein. 385 12


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