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:3.4.21.9 (enterokinase)
675 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thin layer urea isoelectric focusing is a powerful tool for a rapid and reproducible high resolution separation of cholecystokinin stimulated human pancreatic proteins. In pancreatic juice of patients without pancreatic disease, 11 main protein bands were separated and distinguished by Coomassie Blue-R 250 staining. A number of faint protein bands divided among the whole pH range demonstrate a wide microheterogeneity of exocrine pancreatic proteins. Secretory protein patterns of patients with chronic pancreatitis are shown to be different from those of patients without pancreatic disease. Significant alterations were found at the acidic protein band region of pI 4.4 to 4.7. In two cases of chronic pancreatitis the IEF pattern was very similar to that obtained by a short time enteropeptidase incubation of pure pancreatic juice from patients without pancreatic disease.
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PMID:[Isoelectric focusing of pure human pancreatic juice. 1. Examination of patients with and without pancreatic diseases]. 206 65

A monoclonal antibody, hek-1, was raised against enterokinase or enteropeptidase that had previously been partially purified from human duodenal fluid. Hek-1 showed staining of two glycoprotein bands of relative molecular weights of 260,000 and 240,000 on immunoblot analysis of partially purified enterokinase and of ammonium sulfate fraction of duodenal fluid. An enzyme immunoassay for human enterokinase was developed, making use of hek-1. Sensitivity to enterokinase was 20 times higher than that of the conventional assay where BAPA was used as a substrate. The immunohistochemical study with hek-1 showed staining of the brush border membrane and some goblet cells of the duodenum and upper jejunum but no staining of the colon epithelium.
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PMID:Monoclonal antibody against human enterokinase and immunohistochemical localization of the enzyme. 219 31

The effects of aging upon pancreatic digestive enzymes were studied in 27- and 3-month-old Fischer 344 rats. Mean pancreatic weight, protein and DNA concentration and content, and protein-DNA ratios did not differ in the two groups of animals. Pancreatic amylase concentration was reduced by 41% and lipase concentration was increased by 29% in the aging animals, whereas, trypsinogen concentrations did not differ. Young and aging rats were fed diets enriched with fat (72%) or sucrose (75%) for seven days to define whether the different enzyme contents were intrinsic to the aging process or adaptable. In young, but not in aging rats, lipase concentration increased 25% during high fat compared to high sucrose diet feeding. High starch diet feeding induced a 26% increase in amylase in young rats but not in the old. Trypsinogen concentration was unaffected by dietary manipulation. Jejunal enteropeptidase concentration was modestly reduced in the aging rat. Postprandial luminal concentrations of trypsin and amylase did not differ in the two groups. Thus, aging may induce modest changes in pancreatic digestive enzymes and in jejunal enteropeptidase which are unlikely to be physiologically important. However, the pancreas of aging rats does not adapt to changes in dietary intake as well as young rats.
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PMID:Influence of aging upon pancreatic digestive enzymes. 242 64

The mechanism leading to exocrine pancreatic disease in children differs from those encountered in adult patients: I. In acute pancreatitis autodigestion of the gland by proteolytic enzymes may occur and two mechanisms may play a role. 1. Reflux of biliary secretions (e.g. in malformations of the duct system) facilitates activation of trypsinogen by enteropeptidase and leads to the presence of active proteolytic enzymes in the gland (exogenous activation). 2. Lysosomal enzymes may play a role in the intracellular activation of zymogens if inflammation leads to a fusion of lysosomes with zymogen granules (endogenous activation). II. In chronic relapsing and hereditary pancreatitis malformations of the pancreatico-biliary duct system must be sought because surgery may be indicated (common channel syndrome and choledochal cysts). III. Among the hereditary diseases leading to pancreatic insufficiency cystic fibrosis (CF) plays the main role. Haplotype analysis has shown that two genetically different types of CF exists (PS and PI). The pancreas shows manifest insufficiency only in the PI-types which occur in more than 70% of cases but the distribution of haplotypes is different in different ethnic groups. In spite of the recent discovery of the cystic fibrosis gene the exact mechanism leading to exocrine pancreatic dysfunction in CF is not clear, but diminished chloride and bicarbonate secretion, may be the result of a disturbance in the regulation of chloride channels, on acinar or ductular level. In the Shwachman-Diamond syndrome a very severe type of exocrine insufficiency with unknown etiology is encountered at birth.
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PMID:[Physiopathology of the exocrine pancreas in children]. 269 2

Bovine enterokinase (enteropeptidase) activates trypsinogen to trypsin at pH 8.0. In the presence of chicken ovomucoid, a stable complex of ovomucoid-trypsin is produced, inactivating trypsin and eliminating autoactivation of trypsinogen. The molecular size of trypsin (24,000 Da) is increased twofold on forming the ovomucoid-trypsin complex (52,000 Da). Size-exclusion chromatography on a Toya Soda TSK G2000SW column in an HPLC system and with computer-assisted analyses gives a direct quantitative determination of the amount of substrate (trypsinogen) and product (ovomucoid-trypsin). The rate of disappearance of substrate is equal to the rate of formation of product in agreement with kinetic theory. The simultaneous determination of both rates increases the reliability of the assay. The HPLC assay has an extended linear range for the velocity of the activation process as a function of enzyme concentration. The assay is reliable and accurate for highly purified preparations, samples at different steps in the purification scheme, and for a direct assay of the intestinal contents. The assay should be useful in clinical analyses.
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PMID:A direct high-performance liquid chromatography assay of the enzymatic activity of enterokinase (enteropeptidase). 271 84

A case of arrhythmogenic right ventricular dysplasia in a 10 year old girl is described which provides some evidence for an inherited aetiology of this unusual form of heart disease. The parents of this child were first cousins, thus increasing the possibility of inherited disorders in their offspring. She had been known from infancy to have the rare disorder of congenital deficiency of intestinal enteropeptidase, and low serum immunoglobulins G and A. An untyped adenovirus was grown from a myocardial biopsy taken early in the course of her cardiac disease. However, it is unlikely that this virus was a major factor in the aetiology of her cardiac disease. Both the cardiac and intestinal diseases are now commonly believed to result from hereditary factors, and this report provides further support for this view.
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PMID:Arrhythmogenic right ventricular dysplasia in a child with congenital enteropeptidase deficiency and hypogammaglobulinaemia. 273 84

An enterokinase (Enteropeptidase, EC. 3.4.21.9) has been described in the pharate adult of Glossina mositans morsitans. The enzyme is present in pharate adults, 21 days after pupation. It activated commercial crystalline bovine trypsinogen to trypsin. It showed affinity for concanavalin A bound to sepharose and was reversibly sensitive to boiling at pH 6.0. The apparent molecular weight, as determined by gel permeation on sepharose 6B-CL, suggests self-aggregation or an association with a large molecule (M.Wt. approximately equal to 2.5 X 10(6)).
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PMID:An enterokinase in the gut of pharate adult of Glossina morsitans morsitans Westwood (Diptera: Glossinidae). 285 54

The activities of enteropeptidase, alanine aminopeptidase, sucrase, and leucine aminopeptidase were determined in mucosa biopsies taken from three defined places of the duodenum and in duodenal juice. We examined 23 adults with a histological proven normal mucosa and 10 patients suffering from duodenitis grade I. Using multivariate evaluation of all the four enzyme activities of the three mucosa sites, we could differentiate duodenitis from normal mucosa with an efficiency of 88%.
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PMID:[Biochemical diagnosis of duodenitis]. 287 20

In the 1950's, the specific cleavages of the peptide bonds occurring in bovine cationic chymotrypsinogen and trypsinogen were among the first examples of limited proteolyses. According to the split bond(s), the precursor is transformed into enzyme or different forms of zymogen or again into inert protein. The conversion of trypsinogen into trypsin triggers the activations of all the other enzyme precursors of pancreatic juice. In the pancreas, several factors oppose trypsinogen autoactivation, whereas, in the duodenum, all the conditions are favorable for trypsinogen activation by enteropeptidase.
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PMID:Limited proteolyses in pancreatic chymotrypsinogens and trypsinogens. 314 4

The specificity of the synthetic substrate Gly-[L-Asp]4-L-Lys 2-naphthylamide originally developed for the assay of enteropeptidase (EC 3.4.21.9), was investigated with partially purified aminopeptidase. Our results indicate that, not only enteropeptidase, but also the concerted action of the aminopeptidases of the rat small intestine, can rapidly release 2-naphthylamine from the substrate. A previously undescribed, highly active, dipeptidylaminopeptidase, which hydrolyses a Gly-Asp dipeptide from the N-terminus of the substrate, was detected in rat small intestine. The resulting [L-Asp]3-L-Lys 2-naphthylamide fragment is then degraded by a combination of aminopeptidase A and N to yield free 2-naphthylamine. Thus the present substrate cannot be regarded as being specific for enteropeptidase, and its use leads to an over-estimation of enteropeptidase activity in homogenates and extracts of intestinal tissue. In order to prevent this non-specific hydrolysis by aminopeptidases, stereoisomeric substrates with the sequence L-Ala-D-Asp-[L-Asp]3-L-Lys methyl ester, D-Ala-[L-Asp]4-L-Lys methyl ester and L-Ala-[Asp]4-L-Lys methyl ester were synthesized and tested as alternative substrates by their ability to inhibit the enteropeptidase-catalysed activation of trypsinogen.
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PMID:Specificity studies on enteropeptidase substrates related to the N-terminus of trypsinogen. 329 38


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