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)

It was the purpose of this study to define the chromogranin A-processing proteinases present in highly purified preparations of bovine chromaffin granules. The most active enzyme had a pH optimum of 5.0 and was inhibited by pepstatin. It could be identified immunologically as a cathepsin D-like enzyme and subcellular fractionation established its lysosomal origin. After removal of this enzyme the remaining activity at pH 5.0 was mainly due to a cathepsin B-like proteinase. The presence of this enzyme could also be attributed to lysosomal contamination. In the presence of calcium, a further proteolytic activity became apparent at pH 5.0. This enzyme which was inhibited by rho-chloromercuriphenylsulfonic acid was localized in chromaffin granules. A trypsin-like peptidase, most active at pH 8.2, was enriched in a membrane wash of chromaffin granules. Subcellular fractionation indicated that this enzyme is preferentially bound to the membranes of very dense particles probably representing a subpopulation of chromaffin granules. This study establishes that the most active chromogranin A-degrading proteinases present in highly purified chromaffin granules are attributable to lysosomal contamination. Two enzymes with low activity (a Ca2+ activated proteinase and a trypsin-like enzyme) are, apparently, true constituents of chromaffin granules.
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PMID:Chromogranin A-processing proteinases in purified chromaffin granules: contaminants or endogenous enzymes? 215 64

Many unexpected biological functions as bioreactants of the intracellular proteases and their endogenous inhibitors have been found recently. Chymase and tryptase in histamine granules of mast cells and basophile cells play an important role in the process of IgE-mediated degranulation and in the formation of an allergic inflammation profile. Furthermore, the relationship between membrane proteases and their endogenous inhibitor has been taken up as a key and key-hole relation which plays an important role for special recognition apparatus of biological information like the relation of peptide hormones (growth factors) and their specific receptors. Amino acid sequences of the active site of trypstatin are homologous with the neutralizing epitope beta of gp120 of AIDS virus (HIV-1). The trypstatin and anti-tryptase M antibody inhibited syncytium formation in HIV infected Molt 4, clone 8 cells. Therefore, the relationship between tryptase M with trypstatin and the recognition site of epitope beta of HIV-1 with the receptor of helper T-cells are the common keys. The precursor of Alzheimer's deposition protein contains a Kunitz-type trypsin inhibitor domain. The A4-precursor proteins are located in axons of pyramidal neurons in brain and secretory granules of chromaffin cells in adrenal medulla. Those may be secreted into the extracellular milieu. We propose that the A4 inhibitor inhibits a special type of tryptase in the brain and disturbs the complete degradation of secreted A4-precursor protein causing amyloid deposition in alzheimer disease by abnormal proteolysis. Human c-Ha-ras p21 shows 58% homology with cystatin beta, an endogenous inhibitor of cathepsin. Actually, p21 inhibits cathepsin L specifically, but not cathepsin H, papain and cathepsin B. However, the metabolic significance of this inhibitory activity is still unknown.
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PMID:New biological functions of intracellular proteases and their endogenous inhibitors as bioreactants. 220 23

Protein breakdown in submandibular glands rendered hypertrophic by amputation of the lower incisor teeth in rats was investigated. Reduced protein breakdown was observed in the hypertrophic gland tissues, and was found to be inhibited by 20 mM epsilon-amino-n-caproic acid, an inhibitor of serine protease, and 50 microM leupeptin, an inhibitor of trypsin, plasmin, papain and cathepsin B, but not by 2 mM PMSF (phenylmethylsulfonyl fluoride), an inhibitor of serine protease, 10 microM pepstatin, an inhibitor of cathepsin D and 20 microM antipain, an inhibitor of cathepsin A and B. These results suggest that some serine proteases and leupeptin-sensitive proteases (presumably cathepsin B) participate in protein breakdown in hypertrophic gland tissues, and that hypertrophy of the submandibular glands is closely related to the reduced protein breakdown in these tissues.
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PMID:Protein breakdown in submandibular glands rendered hypertrophic by amputation of lower incisor teeth in rats. 223 Sep 61

Bovine spleen cathepsin B contains 7 disulfide bridges. Cleavage of the enzyme with cyanogen bromide gives rise to a large and a small fragment. The former contains all disulfide bridges. Their arrangement was determined by analysis of amino-acid sequences and compositions of subfragments prepared by cleavage of the large cyanogen-bromide fragment with trypsin, chymotrypsin and the staphylococcal proteinase using specific methods for the detection of S-S-bonds. Disulfide bridges link together Cys14-Cys43, Cys26-Cys71, Cys62-Cys128, Cys63-Cys67, Cys100-Cys132, Cys108-Cys119 and Cys148-Cys252.
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PMID:Disulfide bridges of bovine spleen cathepsin B. 239 Feb 14

Sera from patients of biliary, alcoholic, and idiopathic acute pancreatitis with severity scored from 1 to 5 based on the Ranson criteria were tested for proinsulin/insulin degrading activity. Proinsulin degrading activity by normal controls was 8 +/- 4% as compared with 22-78 +/- 17% with a mean of 45% by the patient sera. An order of magnitude increase of proinsulin degrading activity was accompanied by an order of magnitude increase of immunoreactive pancreatic cationic trypsin(ogen) and (pro)elastase-2 as determined by radioimmunoassay with day 1 sera. Proinsulin degrading activity also showed a negative correlation with the clinical time course and dropped to normal by 6 days after admission. The decrease of proinsulin degrading activity was concomitant with a decrease of serum immunoreactive pancreatic serine proteases. High-performance liquid chromatography analysis of the proteolysis products showed the appearance of insulin and smaller peptides with no proinsulin conversion intermediates. Ninety to ninety-eight percent of proinsulin degrading activity was inhibited by anti-alpha 2-macroglobulin (alpha 2-M) antiserum, or (Ac)Eglin-C(J141), and 52% by an elastase and chymotrypsin-specific inhibitor, MeOSuc-Ala-Ala-Pro-boroVal-pinacol. E64c, TLCK, alpha 1-protease inhibitor (alpha 1-PI), or Trasylol inhibited proinsulin degrading activity by 10-17%, and anti-cathepsin B antiserum by 9%. The observed proinsulin degrading activity did not correlate with the Ranson's scores, age, sex, etiology, total serum immunoreactive insulin, calcium, albumin or alpha 2-M but had a negative correlation with serum alpha 1-PI (r = -0.55) and a positive correlation with serum esterase activity (r = .62).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Proteolytic degradation of human recombinant proinsulin/insulin by sera from acute pancreatitis patients and complete inhibition by Eglin-C. 240 52

Hydrolytic activity of cathepsins B, H and trypsin-like proteases was measured in 38 serous middle ear effusion (MEE) samples. The concentrations of (alpha 1-AT) and alpha 2-macroglobulin (alpha 2-M) were also quantitated. The mean value of cathepsin B activity was 25.0 +/- 20.7 RFU and that of cathepsin H was 14.3 +/- 3.0--both significantly higher than those in plasma (1.8 +/- 0.4 RFU, 1.2 +/- 0.3 RFU, p less than 0.005). Very low trypsin-like protease activity could be observed. The mean concentrations of alpha 1-AT and alpha 2-M were 368 +/- 94.8 mg/dl and 57.5 +/- 57.3 mg/dl. The bulk of alpha 1-AT in MEEs was occupied by free alpha 1-AT, which can saturate exogenous trypsin. Due to the very low molar concentration of alpha 2-M in MEEs, thiol proteases (mainly cathepsin B) could be a possible major factor inflicting proteolytic injury on the middle ear mucosa and reflecting the severity of the inflammatory process.
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PMID:Lysosomal thiol proteases (cathepsin B-like proteases) in serous middle ear effusions from adult patients. 242 71

In an effort to develop a model of chronic alcoholic pancreatitis in Sprague-Dawley rats fed a nutritionally adequate diet, 3 groups of 15 animals each were fed Wayne Rodent-Blox ad libitum, Lieber-DeCarli diet with 40% of carbohydrate calories replaced by ethanol ad libitum and isocaloric amounts of Lieber-DeCarli diet respectively for a period of 18 months. Rats were anesthetized and basal and secretin-stimulated pancreatic juice was obtained. Pancreatic glands were isolated and divided into portions for histology, biochemical analyses, and cell fractionation. The homogenate, zymogen granule fraction, mitochondrial-lysosomal fraction, microsomal fraction and postmicrosomal supernatant as well as aliquots of pancreatic juice were analyzed for cathepsin B, acid phosphatase, beta-D-glucoronidase, arylsulphatase and leucine naphthylamidase. All of the ethanol-fed animals developed morphological changes akin to human chronic pancreatitis. There were focal areas of parenchymal degeneration with fibrosis, protein plug formation and tubular complexes. In the pancreatic tissue of animals fed ethanol, total protein, trypsinogen (and free trypsin) were increased and amylase was decreased. While acid phosphatase was increased in all of the particulate fractions, cathepsin B was increased in the zymogen granule and mitochondrial-lysosomal fractions. Basal and post-secretin pancreatic juice did not show a significant increase in digestive or lysosomal enzymes. It is suggested that focal degenerative changes may be due to trypsin generated by intracellular activation of digestive enzymes by lysosomal enzyme cathepsin B.
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PMID:Alcoholic pancreatitis in rats fed ethanol in a nutritionally adequate liquid diet. 244 6

The activation of zymogen proteases and lysosomal enzyme cathepsin B in the pancreas was investigated in cerulein-induced pancreatitis in rats. Acute pancreatitis was induced by two intraperitoneal injections of 40 micrograms/kg of body weight of cerulein at intervals of 1 h. After the first cerulein injection, the active trypsin and elastase contents in the pancreas tissues significantly increased, and reached the highest level at 3 h after the first injection, followed by peaks at 5 h in the serum amylase and lipase levels and the pancreas wet weight. Cathepsin B contents in pancreas tissues showed a parallel increase with active zymogen enzymes during the first 3 h of pancreatitis. These findings may suggest that the intracellular activation of trypsinogen is an important step in the development of cerulein-induced acute pancreatitis and that cathepsin B plays a role in the activation of trypsinogen in pancreatic acinar cells.
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PMID:Activation of proteases in cerulein-induced pancreatitis. 247 99

Histochemical analysis of some lysosomal and sarcoplasmic proteolytic enzymes was assayed in human myocardial biopsies taken from 26 cardiopathic patients subjected to open heart operations, under extracorporeal circulation and protection with cardioplegic solution and hypothermia. The investigated myocardial proteases were: cathepsin B, cysteine aminopeptidase, acid gelatinases, trypsin-like endopeptidase, chymotrypsin-like endopeptidase and neutral gelatinases. The effects of surgical interventions appreciated by comparing the myocardium fragments harvested before, and at various intervals after aorta clamping (6-90 minutes) revealed disorders in the activity and compartmentalization of all the investigated proteases, whose histochemical reactions increased between 10 and 20 minutes after aorta clamping and manifested a lowering tendency with sarcoplasmic diffusion and extracellular release at longer periods than 20 minutes. The early activation of the neutral proteases and their sarcolemmal expression even before 10 minutes after aorta clamping, suggested the involvement of the nonlysosomal proteases in the first proteolytic events implied in the molecular membrane damage of the myocardial fibre. Sequential proteolytic cascades of abnormal neutral and acid proteases were emphasized as possible mediators and effectors of molecular and subcellular damages suffered by the myocardial fibers during the open heart operations, even under cardioplegic and hypothermic protection.
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PMID:Histochemical reactions of myocardial proteases during open heart surgery. 252 27

Crevicular fluid samples were collected from 20 gingivitis and periodontitis patients using filter paper strips; these were then eluted into buffer. Portions of each sample were combined and the activities of this pooled eluate against different peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin (AFC) were examined with respect to their pH profiles and effector responses. Ca-thepsin B- and L-like activity was detected with Bz-Val-Lys-Lys-Arg-AFC; elastase-like activity with MeOSuc-Ala-Ala-Pro-Val-AFC; tryptase-like activity with Z-Ala-Ala-Lys-AFC; trypsin-like activity with Z-Gly-Gly-Arg-AFC; and dipeptidyl peptidase (DPP) IV-like activity with Ala-Pro-AFC. The selectivity and sensitivity of these assays were improved by choice of appropriate conditions. The cathepsin B- and L-, elastase-, tryptase-, and trypsin-like activities all had properties consistent with those from host sources, whilst partial inactivation of the DPP IV-like activity by heat treatment (60 degrees C for 30 min) suggested that it may have represented a mixture of human and Bacteroides gingivalis enzymes. Individual patient eluates showed wide variations in enzyme concentrations, but generally elastase-like activity was by far the highest. The sensitivity of the assays with AFC-linked substrates was such that it should prove possible to measure all five different types of activity in crevicular fluid samples from local periodontal disease sites.
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PMID:Detection of cathepsin B- and L-, elastase-, tryptase-, trypsin-, and dipeptidyl peptidase IV-like activities in crevicular fluid from gingivitis and periodontitis patients with peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin. 257 34


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