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)

The effect of heparin on the activation of trypsinogen by enterokinase and on trypsin activity has been investigated. Proteolytic activity of trypsin has been determined using caseinolytic method. It has been found that heparin inhibits trypsinogen activation only when it is preincubated with proenzyme before introduction of enterokinase to the tested system. In these experimental conditions heparin in final concentrations from 1 to 20 U/ml exhibits inhibitory effect diminishing trypsinogen activation to about 65% initial activity and in higher concentrations only to 50%. Heparin introduced to the tested system simultaneously with enterokinase or to the active trypsin did not appear evident inhibitory effect.
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PMID:The inhibitory effect of heparin on trypsinogen activation with enterokinase. 93 May 38

The interrelationship of enterokinase and trypsin activities were investigated in 133 infants and children with a variety of gastrointestinal and pancreatic disorders. Fourteen patients with diarrhea and grade II mucosal injury revealed a significant (P less than 0.01) reduction of enterokinase, trypsin, and disaccharidase activites as compared to 59 children with normal mucosa. Nine patients with cystic fibrosis and pancreatic insufficiency had normal mucosal enterokinase activity and elevated intraluminal enterokinase activity with very low or no trypsin activity. Patients with hypoproteinemia and gastrointestinal protein loss, associated with intestinal lymphangiectasia (4 patients) and intestinal lymphoid nodular hyperplasia (3 patients), had normal or insignificant decrease of enterokinase and trypsin activities. In patients with steatorrhea, a normal sweat test, normal intestinal mucosa, and absent trypsin activity, two entities were defined. One group (3 patients) was diagnosed as Schwachman-Diamond syndrome with pancreatic insufficiency and normal mucosal and intraluminal enterokinase activity. The second group (2 patients) with absent mucosal and intraluminal enterokinase activity and normal lipase and amylase activities was diagnosed as congenital enterokinase deficiency.
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PMID:Enterokinase and trypsin activities in pancreatic insufficiency and diseases of the small intestine. 94 55

A method is described for the purification of human enterokinase from accumulated duodenal fluid by affinity chromatography using p-aminobenzamidine as the ligand. Resolution was greatest when glycylglycine was substituted as the spacer arm. Purification was not a one-step procedure, and some contamination, principally by the alpha-glucosidases, remained. Their removal was completed by immunoadsorption using antisera raised to enterokinase-free material containing these enzymes, prepared as a by-product of the purification procedure. The final preparation had an activity of 4260 nmol of trypsin/min per mg and was free of other enzymic activity tested. Amino acid and sugar analyses of the highly purified enzyme indicated an acidic glycoprotein containing 57% sugar (neutral sugars 47%, amino sugars 10%). The apparent mol.wts. and Stokes radii of human and pig enterokinase were 296 000 and 316 000, and 5.65 and 5.78 nm respectively. Two isoenzymes were identified for human enterokinase and three for the pig enzyme. Human enterokinase demonstrated a resistance to reduction of disulphide linkages and to sodium dodecyl sulphate binding, which may be related to the need for it to retain its integrity in the digestive environment of the upper small intestine. Antisera to highly purified pig and human enterokinases specifically inhibited enterokinase activity. Immuno-inhibition of intestinal aminopeptidase, maltase and glucoamylase by homologous antisera was not observed.
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PMID:The purification of human enterokinase by affinity chromatography and immunoadsorption. Some observations on its molecular characteristics and comparisons with the pig enzyme. 94 36

In this study the influence of 14 antibiotics, 12 of them orally applicable, on human enterokinase was investigated. The effects of these substances on the activities of human disaccharidases were also examined. The enterokinase activity is more sensitive to the studied antibiotics than is human lactase, saccharase or isomaltase. Unphysiologically high concentrations of penicillins, cephalexin and chloramphenicol (10(-2) Mol/l) inhibited enterokinase, tetracycline (doxycycline) in a dose of 10(-3) m reduced the activity of this enzyme by 50%, neomycinsulphate and the sulphates of polymyxin B and E have no effect on the disaccharidases. On the contrary, these substances are the best inhibitors of enterokinase among the tested antibiotics. Neomycin or polymyxin (10(-4) Mol/l) causes a 50% inhibition of a physiological quantity of this enzyme. Therapeutic doses of both antibiotics may reduce the enterokinase activity by 70% to 90%, while the activity of trypsin is not affected unless a concentration greater than 10(-2) m is used. The inhibition is not only caused by the anion (SO4) of these antibiotics, since sulphates reduce the enterokinase only in concentrations higher than 10(-3) Mol/l in man. The mechanism of inhibition is not effected by binding cholic acids under test conditions. Both polymyxin and neomycin inhibit the enterokinase activity with and without glycodeoxycholic acid. Further studies showed that the type of inhibition is competitive in both cases. The inhibition constant K2 of neomycin-B-sulphate is 8.7X10(-5) Mol/l, of polymyxin-E-sulphate 8.6X10(-5) Mol/l. The inhibition type of penicillins, cephalosporins and doxycycline is noncompetitive, thus contrasting that of neomycin and polymyxin.
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PMID:[The influence of orally applicable antibiotics on the activities of human enterokinase and disaccharidases (author's transl)]. 98 20

The two human anionic trypsinogens 1 and 2 were purified from human pancreatic juice by gel filtration on Sephadex G-100 and by chromatography on DEAE-cellulose. After activation of their respective zymogens by porcine enterokinase, human trypsins 1 and 2 were studied for their reaction with a wide variety of proteinase inhibitors. Kunitz pancreatic trypsin inhibitor and human pancreatic secretory trypsin inhibitor completely inhibited both human trypsins at a stoichiometric inhibitor-to-enzyme ratio of one to one. In contrast, bovine pancreatic secretory trypsin inhibitor (Kazal's inhibitor) failed to inhibit either human trypsin. The inhibition of both human trypsins by porcine pancreatic secretory trypsin inhibitor was demonstrated. The reactions of the trypsins with chicken ovomucoid, Ascaris lumbricoides (type suis), human sperm and blood plasma trypsin inhibitors were studied. The most striking difference between the two human trypsins was the reaction with soybean trypsin inhibitor (Kunitz). Trypsin 2 was completely inhibited in a one-to-one molar ratio while trypsin 1 was poorly inhibited. The presence of a prekallikrein in human pancreatic juice is discussed.
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PMID:The two human trypsinogens. Inhibition spectra of the two human trypsins derived from their purified zymogens. 107 68

An in vitro system of guinea pig pancreatic lobules convenient for the study of secretory processes is described in this paper. In this system: (a) the over-all glandular architecture of the tissue is preserved: lobules remain morphologically intact through 5 hours; (b) amylase discharge from unstimulated lobules is low (similar to 4%/hour) and linear over the 5 hours tested; (c) response to carbamylcholine chloride (10-5 M) is energy-dependent, rapid, and extensive (92% discharge of amylase by 5 hours); (d) initial rates of discharge remain stable over the first 3 hours; and (e) no autoactivation of zymogens occurs in incubation medium or tissue. The activation of four zymogens, i.e. chymotrypsinogen, trypsinogen, and procarboxypeptidases A and B, was studied using the following criteria for optimal activation: (a) maximal activation attainable under experimental conditions; (b) stability at the level of maximal activation; and (c) linear relationship between amounts of protein activated and enzyme activity elicited by activation. The concentration of activators (trypsin or enterokinase) and secretory protein, the presence or agents (bovine plasma albumin or Triton X-100) which minimize adsorptive losses of secretory protein on glass or plastic surfaces, and the temperature at which activation is carried out were found to be critical and different for each of the zymogens tested. The kinetics of the appearance of three enzyme activities (amylase, lipase, and ribonuclease) and four potential proteolytic activities (chymotrypsinogen, trypsinogen, and procarboxypeptidases A and B) into the incubation medium was studied under different conditions; i.e. rest and stimulation with various secretogogues (carbamylcholine chloride, caerulein, and pancreozymin). All seven activities estimated to represent similar to 75% of the secretory protein output of the exocrine pancreas were discharged in synchrony and in constant proportions and were released from the tissue to the same extent under each experimental condition investigated.
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PMID:Studies on the guinea pig pancreas. Parallel discharge of exocrine enzyme activities. 112 25

Precursors of proteolytic enzymes were demonstrated in the peritoneal inflammatory exudate during acute experimental pancreatitis of the rat. This was done by separating the proteinase inhibitors and proenzymes by gel filtration on Sephadex G-200. After elution the proenzymes could be demonstrated by activating them with enterokinase or with trypsin. The proenzymes were eluted after the main protein bulk and proteinase inhibitors. Enzyme precursors were absent from the exudate of formalin-induced peritonitis, which suggests that the proenzymes present in the exudate of pancreatitis are of pancreatic origin. The demonstration of proenzymes in perripheral blood during pancreatitis was tested with the several modifications of the same methods, but the results were not convincing, probably owing to the insensitivity of the methods used.
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PMID:The proteolytic proenzymes in the peritoneal exudate during acute experimental pancreatitis of the rat. 115 82

Elastolytic activity of human duodenal contents was determined using the new chromogenic substrate succinyl-trialanine-p-nitroanilide (Suc-Ala3-NAp). The mean output values after pancreatic stimulation with pancreozymin and secretin were significantly higher in controls than in subjects with impairment of other secretory values (volume, bicarbonate, amylase, lipase). Agar gel electrophoresis and chromatography on DEAE-Sephadex revealed one to two fractions which differed in mobility (cathodic and anodic fraction), elution with different NaCl concentrations (0.15 M, cathodic fraction; 0.3 M, anodic fraction), and in behaviour towards synthetic and natural substrate (Suc-Ala3-NAp) and elastin-Congo Red). The cathodic fraction cleaved both substrates, whereas the anodic fraction cleaved only Suc-Ala3-NAp. After trypsin and enterokinase treatment the anodic fraction behaved as the cathodic fraction on DEAE-Sephadex chromatography. The molecular weights (Sephadex G-100) and the Michaelis constants (Suc-Ala3-NAp) of both fractions were identical (24 500; 0.45 X 10(-3) M). These fractions represent probably diffenent activation forms of pancreatic elastase.
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PMID:Elastolytic activity of human duodenal contents. 117 3

The authors carried out studies on 15 rabbits (9 controls and 6 experimental and examined the motor activity of the duodenum after infusing duodenal content from patients with clinicaly established diagnosis of chronic hepatitis at precirrhotic stage. The duodenal secretion obtained from the patients, was examined in advance and the activity of enterokinase and trypsin was determined. The obtained results showed that during infusion of saline or duodenal content, taken from healthy persons, the control group did not reveal any change in the motor activity of the duodenum. In the experimental group after infusion fo duodenal content, taken from patients with liver disease, there was a demonstrative inhibition of the motor activity of the duodenum after the third infusion in all trials. The motor activity was vot normalized for a period of 5-6 hours. There was a reduction in the activity of the enzymes enerokinase and trypsin under the normal values in the doudenal content, taken from patients with chronic hepatitis before its infusion. This coincided with the literary data.
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PMID:[The effect of heterologous duodenal content on the motor activity of the duodenum]. 121 16

In rats fed control and ethanol-containing Lieber-DeCarli diets for a period of 12 months, the bile did not contain any enterokinase, the pancreatic juice did not contain any plasmin or thrombin, but in animals fed high fat diet with ethanol, trypsinogen and chymotrypsinogen were significantly increased and trypsin inhibitor decreased. In the tissue, free trypsin and cathepsin B were increased. Composite profile of trypsinogen in gel segments obtained from the pancreatic juice and the tissue showed higher peaks of cationic and anionic variants of trypsinogen in animals fed ethanol. There was no evidence of mesotrypsinogen or of enzyme Y in the juice or the tissue. These studies show that serine proteases and cathepsin B may play a major role in the pathobiology of alcoholic pancreatitis.
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PMID:Effect of chronic ethanol feeding on factors leading to inappropriate intrapancreatic activation of zymogens in the rat pancreas. 128 69


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