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)

A method--enzymoblotting--was developed for localizing various enzymes after electrophoretic separation, transfer to nitrocellulose, and incubation with specific substrates. As an application, the proteinases porcine trypsin (EC 3.4.21.4), bovine chymotrypsin (EC 3.4.21.1), porcine elastase (EC 3.4.22.11), and their zymogen forms from porcine pancreas homogenate were analyzed utilizing specific p-nitroanilide substrates. After agarose gel electrophoresis, transfer of the separated proteinases to a nitrocellulose membrane was performed by capillary diffusion for 30 min. After air-drying of the nitrocellulose membrane, it was incubated in the appropriate substrate solution for 60 min. N-alpha-Benzoyl-DL-arginine-para-nitroanilide HCl was used as a substrate for trypsin, N-benzoyl-L-tyrosine-para-nitroanilide and succinyl-L-phenylalanine-para-nitroanilide for chymotrypsin, and N-succinyl-L-alanyl-L-alanyl-L-alanine-para-nitroanilide for elastase. p-Nitroaniline, the product thus obtained, was diazotized with N-(1-naphthyl)ethylenediamine to a red azo dye, visible at the site of the proteinases on the nitrocellulose membrane. The results could be preserved at -18 degrees C. Zymogen forms of the pancreas proteinases were detected in a similar manner. They were converted to active proteinases in situ on the nitrocellulose membrane after preincubating the nitrocellulose membrane in the activation enzymes enteropeptidase or trypsin.
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PMID:Enzymoblotting: a method for localizing proteinases and their zymogens using para-nitroanilide substrates after agarose gel electrophoresis and transfer to nitrocellulose. 351 6

A specific enterokinase inhibitor (EKI) was purified from red kidney bean (RKB). Male weanling rats fed a diet containing this purified EKI (0.06%) for 6 d showed increases in mucosal weights, protein, DNA and lactic dehydrogenase contents in their small intestines compared to age-matched control rats fed a standard diet. Total mucosal EK and disaccharidase activities were, however, decreased in EKI-fed rats. Thus, oral consumption of EKI from RKB led to small intestinal mucosal hyperplasia in rats. The mucosal hyperplasia observed in EKI-fed rats is not likely due to decreased turnover of mucosal proteins as a result of reduced luminal proteases since luminal contents of trypsin, chymotrypsin and elastase in EKI-fed rats were similar to those of control rats. Enterokinase inhibitor may have a direct hyperplastic effect on the small intestine of rats.
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PMID:Small intestinal mucosal hyperplasia caused by an enterokinase inhibitor from red kidney bean in rats. 351 52

Controlled intraduct infusion and peri-acinar dispersal of 100 microliter buffer containing sodium glycodeoxycholate (GDOC) at concentrations of 8.5, 17 and 34 mmol/l in rats caused a progressively severe acute pancreatitis from which none of the animals died over the experimental period. Infusion of affinity-purified active human enterokinase in buffer did not cause pancreatitis, presumably because of the inability of the macromolecule to gain access to its specific intracellular substrate trypsinogens. The addition of enterokinase 200 ng to GDOC 34 mmol/l in the infusate resulted in a severe systemic disturbance and a form of acute necrotizing pancreatitis which was uniformly and rapidly lethal. This effect was not seen when equimolar trypsin was substituted for enterokinase. These findings show that enterokinase specifically increases the lethality of experimental bile salt pancreatitis and suggest that this bile-borne enzyme may in some cases pose a significant clinical threat.
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PMID:Intraduct enterokinase is lethal in rats with experimental bile-salt pancreatitis. 354 76

Protein digestion is a complex process in which most aspects have a developmental pattern of activity. Gastric pH and intestinal peptide and amino acid transport as well as the activities of pepsinogen, trypsin, chymotrypsin, enterokinase and intestinal dipeptidases vary during development. No one species has been assessed for all these aspects and it is not possible to present an integrated developmental view of protein digestion. The following developmental changes, however, have been observed. Gastric pH declines, and peptic and pancreatic proteases exhibit increasing activity in pigs and rats after birth. The increase in pigs is gradual over several weeks starting at birth, whereas the increases in the rat begin at 2 wk, just prior to the time of weaning. The activities of dipeptidases in the rat and pig, peptide transport systems in the guinea pig and rabbit and amino acid transport systems in the rat, rabbit, guinea pig and chicken, however, appear (with few exceptions) to be active in the small intestine at the time of birth. Frequently, these activities peak in the neonate and decline during the postnatal period. In the rat, dietary protein tends to increase the activities of pancreatic proteases and intestinal peptidases and to increase the rate of uptake of amino acids by the intestinal epithelium. Individual dietary amino acids also influence amino acid transport systems. The data indicate that most processes in protein digestion undergo marked changes during prenatal and postnatal development and are influenced by the level of feeding and composition of the diet.
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PMID:Development and adaptation of protein digestion. 388 40

The cascade enterokinase-trypsinogen-prophospholipase A2 lecithin, generating trypsin, phospholipase A2 and lysolecithin, respectively, was studied in vitro using a novel phospholipase A2 assay. The rate of enterokinase catalysed activation of trypsinogen was maximal at 4 mmol/1 glycodeoxycholic acid; higher concentrations of bile salt progressively inhibited enterokinase activity. Net phospholipase A2 activity in reaction mixtures was critically dependent on the trypsin/prophospholipase A2 molar ratio. Lecithin hydrolysis by phospholipase A2 was dependent on the bile salt/lecithin molar ratio and was optimal at 1.25 to 1. The addition of enterokinase to lecithin and bile salt mixtures, containing trypsinogen and prophospholipase A2 at presumed pathophysiological concentrations, resulted in the generation of concentrations of lysolecithin lytic for pancreatic acinar cells within 5 min. These findings would support the concept that the entry of bile containing active enterokinase into the pancreatic duct system in vivo may in some cases be involved in the initiation of necrotising acute pancreatitis in man.
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PMID:The generation of lysolecithin by enterokinase in trypsinogen prophospholipase A2 lecithin mixtures, and its relevance to the pathogenesis of acute necrotising pancreatitis. 390 74

Chronic diversion of pancreatic and biliary secretions away from the proximal small intestine resulted in rapid increases in pancreatic size and protein content in adult rats. The effect was detectable as early as 10 days postsurgery. Differential changes in pancreatic enzymes were evident after bypass. The concentration of trypsinogen remained stable while amylase concentrations showed a marked decrease. Total pancreatic trypsinogen content, however, was increased, while amylase content remained similar to controls. Feeding bypassed rats with chows containing various pancreatic and biliary supplements had no effect on the hyperplastic response of their pancreata. Trypsinogen and amylase levels in supplemented groups remained similar to the bypassed group fed nonsupplemented chow, with the exception of increases in trypsinogen concentration and content in the groups supplemented with bile and cotazyme plus bile acids. The adequacy of oral refeeding of pancreatic biliary components was supported by its effectiveness in restoring mucosal enterokinase activity and trypsin levels in segment 1. However, there was no correlation between tryptic activity in the contents of the bypassed segment and the eventual pancreatic weight. These results indicate that factors other than those supplemented in this study are required in maintaining the steady state of pancreatic growth in normal rats.
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PMID:Enteral feedback control of pancreatic hypertrophy: the role of pancreatic biliary secretions. 394 29

The activation of trypsinogen to trypsin in the small intestine can occur by the action of enterokinase or, alternatively, as an autocatalytic process catalysed by trypsin itself. We have found that bile salts and human bile cause a significant enhancement of the autocatalytic activation of trypsinogen. This effect is dependent on the calcium ion concentration and is most marked around pH 5.4 and 7.8. An optimum concentration exists for each bile salt at which the greatest enhancement occurs. At this concentration, certain bile salts have been shown to produce activation effects of up to 55-fold. It is suggested that this activation of the autocatalytic process by bile plays an important role in protein digestion in the small intestine, since it has been shown previously that duodenal trypsin levels are abnormally low in patients with an impairment of bile secretion.
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PMID:Enhancement of the autocatalytic activation of trypsinogen to trypsin by bile and bile acids. 398 21

The effect of 3 purified trypsin inhibitors and 4 legume seed extracts on teh trypsins and chymotrypsins of the activated pancreata of 11 animal species, including man, was measured. The activation was performed by either homologous enterokinase or by bovine trypsin. Several trypsinogens were not activated by the latter. Rabbit trypsin was the most sensitive to all inhibitor preparations, while the human trypsin was the most resistant, except to the black bean extract. The response of the chymotrypsins was more variable and those of capybara and rabbit showed extreme sensitivity. Considerable differences between the extracts of black and white garden beans, both Phaseolus vulgaris, with respect to their reactivity toward different animal enzymes were detected. No relation between relative pancreas weight and susceptibility toward soybean trypsin inhibitor could be observed.
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PMID:Inhibition of trypsins and chymotrypsins from different animal species: a comparative study. 405 91

An ideal canine model of anomalous pancreaticobiliary ductal union, similar to a human anomaly, was devised. Direct anastomosis of the dorsal pancreatic duct and the choledochus was employed (dorsal pancreaticocholedochostomy). The ventral pancreatic duct was not manipulated. Cylindrical choledochal dilatation results in 13 out of 20 adult dogs and in 4 out of 6 puppies. Dilatation of the intrahepatic biliary tree and thickening of the choledochal wall in a hepatic direction were observed in high ratio among adult dogs. Puppies had less dilatation. The activation of pancreatic enzymes was studied in bile containing pancreatic juice. The proteolytic enzymes, trypsin and elastase were proven to be activated in the bile without the presence of enterokinase in the pancreaticocholedochostomy model. This would be the cause of the ill effects of refluxed pancreatic juice into bile in anomalous pancreaticobiliary ductal union.
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PMID:Experimental analysis of the ill effect of anomalous pancreaticobiliary ductal union. 617 6

Porcine rotaviral infectivity for continuous porcine kidney (PK-15) cells was enhanced by incorporation of pancreatic endopeptidases into the cell culture maintenance medium. Marked enhancement of infectivity was induced by trypsin, whereas elestase and alpha-chymotrypsin enhanced infectivity to a lesser extent. Bacterial protease also induced some enhancement of porcine rotaviral infectivity. A synergistic enhancement of porcine rotaviral infectivity was noticed with trypsin and alpha-chymotrypsin combined. Porcine rotaviral infectivity was not affected by incorporation of alpha-amylase, alkaline phosphatase, beta-galactosidase, carboxypeptidase-A, deoxyribonuclease, enterokinase, lipase, or ribonuclease into the maintenance medium.
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PMID:Porcine rotaviral infection of cell culture: effects of certain enzymes. 624 64


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