Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The results of an evaluation over 4 years (1973-1976) of 16,620 BM-tests (Boehringer-Mannheim newborn screening for cystic fibrosis) at 8 hospitals in Switzerland are presented and the data from analysis of albumin, protein and alpha1-antitrypsin concentrations, and on trypsin-inhibitory capacity of the meconia are discussed. 99.5% of the tests were negative. Of the remaining 0.5% BM-positive tests, the diagnosis of cystic fibrosis required confirmation by sweat test and clinical course in 6 cases, or 0.04% of the total collective. The test was false-negative in 2 cases (0.012%), of which one had a primary pulmonary form of cystic fibrosis. The study shows that the BM-test, as screening test for cystic fibrosis, makes it possible to distinguish between "normal" and "suspect". By calculating the ratio albumin to alpha1-antitrypsin, it would be possible to verify the probability of a reliable diagnosis as early as a few days after birth. As before, however, it would be indispensable to confirm the diagnosis of cystic fibrosis by a sweat test with pilocarpin iontophoresis. By consistent screening in all obstetric and pediatric clinics it would be possible to improve early diagnosis still further.
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PMID:[Screening of newborn infants in cystic fibrosis. Evaluation of a 4-year study in Switzerland]. 30 84

Agarose gel electrophoresis (at pH 8.6) was used for qualitative determination of pancreatic enzymes in duodenal juice. The various enzymes were identified by staining techniques with specific chromogenic substrates, by quantitative determination of enzymes in eluates of gel slices, and by immunoelectrophoresis. The various protein bands corresponded to the following enzymes (from the anode to the cathode): chymotrypsin, trypsin, carboxypeptidase A, chymotrypsin, amylase (around the slit), lipase, elastase, and trypsin. The method was applied to a study of exocrine pancreatic function in 10 adults and 83 children suspected of having malabsorption. The duodenal juice, also analyzed for trypsin and amylase content, was collected in fasting condition and after a test meal of water. In patients with normal pancreatic function, all the enzyme bands were present and easy to recognize. In 87 patients carboxypeptidase A was present as two bands in 68 (80%), anodal trypsin as two bands in 39 (45%), and cathodal trypsin as two bands in 85 (97%). Electrophoresis of duodenal juice gave as much information from the fasting sample as after the test meal. Six children with pancreatic insufficiency (cystic fibrosis and Shwachmar's syndrome) had no or only faintly stained enzyme bands and a strongly stained albumin-containing band most anodally. The method is simple, rapid, and useful in routine work. The combination of this qualitative test with a quantitative one (e.g. trypsin determination) provides good information about exocrine pancreatic function.
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PMID:Agarose gel electrophoresis of duodenal juice in normal condition and in children with malabsorption. 43 37

Protease activity in plasma is assayed using 4-methylumbelliferylguanidinobenzoate. The assay is modified by carrying out the reaction in the presence and absence of benzamidine, a competitive inhibitor of trypsin-like proteases. The parameters of the assay are described in detail. Using this assay, our earlier demonstration of a deficiency of protease activity in plasma of patients with cystic fibrosis is confirmed. The activity, corrected for the nonspecific hydrolysis of 4-methylumbelliferylguanidinobenzoate by benzamidine, is expressed as nanomoles of 4-methylumbelliferone released per milliliter plasma. Under standard conditions, the activity in plasma activated with chloroform-ellagic acid was 127.2 +/- 23.1 in 7 controls, 70.4 +/- 11.7 in 11 obligate heterozygotes, and 48.7 +/- 16.6 in 12 patients with cystic fibrosis. Identical results were obtained when unactivated plasma was used. These data demonstrate that the judicious use of specific inhibitors such as benzamidine might be useful in assaying low levels of protease activity in crude systems.
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PMID:Protease deficiency in plasma of patients with cystic fibrosis. Reduced reaction of 4-methylumbelliferylguanidinobenzoate with plasma of patients with cystic fibrosis. 48 55

This review describes the development and application of a novel test to determine levels of human immunoreactive trypsin, an enzyme produced solely by the pancreas, in biological fluids. Being organ-specific, the assay of immunoreactive trypsin should be an ideal marker of pancreatic function, and this is supported by the results of a number of clinical and research investigations. Use of this assay in studies of chronic pancreatitis, juvenile-onset diabetes, and cystic fibrosis has yielded much valuable data, and it is expected that further research will lead to an improved understanding of these and other conditions associated with the pancreas in health and disease.
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PMID:Radioimmunoassay of trypsin. A new aid in the assessment of pancreatic function. 51 80

Immunoreactive serum trypsin was measured with a double antibody radioimmunoassay in normal subjects and patients with various diseases of the pancreas. The normal range is 115-350 ng/ml with a geometric mean of 212 ng/ml. No trypsin was found in serum after total duodenopancreatectomy, in about 75% of patients with cystic fibrosis and in a few patients with pancreas carcinoma or chronic pancreatitis. Reduced serum trypsin levels between 10 and 100 ng/ml were measured in the remaining 25% of cystic fibrosis and in one third of the patients with chronic pancreatitis. Serum trypsin was increased to 700-17,000 ng/ml in all patients with acute pancreatitis or during the acute phase of chronic pancreatitis. Absent or reduced serum trypsin is a reliable indicator of total or partial exocrine pancreatic insufficiency whereas considerably increased serum trypsin concentration do indicate acute pancreatitis.
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PMID:Immunoreactive serum trypsin in diseases of the pancreas. 52 26

Properties of carboxypeptidase A of cultured skin fibroblasts from control and cystic fibrosis patients were studied using alpha-N-carbobenzoxy-L-glutamyl-L-tyrosine as substrate. Carboxypeptidase A was inhibited by thiomersal, cyanide, iodoacetate and N-ethylmaleimide in a similar manner for control and cystic fibrosis fibroblasts. Both trypsin and dithiothreitol treatment activated the enzyme, but 1,10-phenanthroline inhibited only in the presence of dithiothreitol. Both Zn2+ and Co2+ reversed this inhibition. Trypsin treatment of carboxypeptidase A produced a form of the enzyme having a higher KM value for both control and cystic fibrosis fibroblasts. Dithiothreitol treatment of control fibroblasts resulted in a form with similar properties to the trypsin activated form, but cystic fibrosis fibroblasts yielded a variant form with even higher KM and Vmax values. Since other properties were similar, it seems likely that this difference reflected binding of a molecule to the enzyme rather than of a defect in the enzyme.
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PMID:Carboxypeptidase A activity of cultured skin fibroblasts and relationship to cystic fibrosis. 66 47

Protease activity in cultivated human skin fibroblasts has been quantitated using 4-methylumbelliferylguanidinobenzoate (MUGB), an active site titrant of trypsin-like proteases (7). The reaction of the proteases with MUGB was complete in 1 hr, inhibited both by benzamidine and (p-nitrophenyl)-p'-guanidinobenzoate, but not by p-hydroxymercuribenzoate. The extent of reaction was proportional to protein concentration and independent of MUGB concentration. This activity was present in the particulate fraction of the cell. The mean "titre" values (nanomoles of 4-methylumbelliferone released per mg protein) of the proteases in fibroblasts from eight controls (N), 8 obligate heterozygotes (H), and 14 patients with cystic fibrosis (CF) were: N, 1.27 +/- 0.11; H, 0.82 +/- 0.12; CF, 0.66 +/- 0.10. The differences in the "titre" values for N:CF and N:H were significant (p less than 0.001) as were those for H:CF (p less than 0.01). The mean "titre" value obtained for cultivated control amniotic fluid cells was 1.29 +/- 0.17. These data indicate a reduction in the MUGB-reactive proteases in skin fibroblasts derived from patients with CF when compared either to control or to obligate heterozygotes. These data are consistent with our earlier suggestion (11, 15) that decreased proteolytic levels in the tissues and fluids of patients with CF may be a generalized phenomenon.
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PMID:Reaction of 4-methylumbelliferylguanidinobenzoate with cultivated human skin fibroblasts derived from patients with cystic fibrosis. 68 46

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

Alginate is believed to be a major virulence factor in the pathogenicity of Pseudomonas aeruginosa in the lungs of patients suffering from cystic fibrosis. Guanosine diphospho-D-mannose dehydrogenase (GDPmannose dehydrogenase, EC 1.1.1.132) is a key enzyme in the alginate biosynthetic pathway which catalyzes the oxidation of guanosine diphospho-D-mannose (GDP-D-mannose) to GDP-D-mannuronic acid. In this paper, we report the structural analysis of GMD by limited proteolysis using three different proteases, trypsin, submaxillary Arg-C protease, and chymotrypsin. Treatment of GMD with these proteases indicated that the amino-terminal part of this enzyme may fold into a structural domain with an apparent molecular mass of 25-26 kDa. Multiple proteolytic cleavage sites existed at the carboxyl-terminal end of this domain, indicating that this segment may represent an exposed region of the protein. Initial proteolysis also generated a carboxyl-terminal fragment with an apparent molecular mass of 16-17 kDa which was further digested into smaller fragments by trypsin and chymotrypsin. The proteolytic cleavage sites were localized by partial amino-terminal sequencing of the peptide fragments. Arg-295 was identified as the initial cleavage site for trypsin and Tyr-278 for chymotrypsin. Catalytic activity of GMD was totally abolished by the initial cleavage. However, binding of the substrate, GDP-D-mannose, increased stability toward proteolysis and inhibited the loss of enzyme activity. GMP and GDP (guanosine 5'-mono- and diphosphates) also blocked the initial cleavage, but NAD and mannose showed no effect. These results suggest that binding of the guanosine moiety at the catalytic site of GMD may induce a conformational change that reduces the accessibility of the cleavage sites to proteases. Binding of [14C]GDP-D-mannose to the amino-terminal domain was not affected by the removal of the carboxyl-terminal 16-kDa fragment. Furthermore, photoaffinity labeling of GMD with [32P]arylazido-beta-alanine-NAD followed by proteolysis demonstrated that the radioactive NAD was covalently linked to the amino-terminal domain. These observations imply that the amino-terminal domain (25-26 kDa) contains both the substrate and cofactor binding sites. However, the carboxyl-terminal fragment (16-17 kDa) may possess amino acid residues essential for catalysis. Thus, proteolysis had little effect on substrate binding, but totally eliminated catalysis. These biochemical data are in complete agreement with amino acid sequence analysis for the existence of substrate and cofactor sites of GMD. A linear peptide map of GMD was constructed for future structure/functional studies.
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PMID:Characterization of guanosine diphospho-D-mannose dehydrogenase from Pseudomonas aeruginosa. Structural analysis by limited proteolysis. 137 Apr 73

Neonatal screening for cystic fibrosis (CF) reduces short-term morbidity but its long term effects remain to be demonstrated. The best available method is the assay of immunoreactive trypsin in dried blood spots, and specificity can be improved by adding direct or indirect genetic analysis. Pregnancies known to be at risk of CF can also be screened by molecular methods, and affected pregnancies terminated. The application of genetic testing to whole communities, to detect unknown heterozygotes, raises many questions which require consideration by society and the health professions. The development of effective treatment of the basic abnormality of cell function in CF would enhance the need for neonatal screening, and possibly reduce the requirement for abortion.
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PMID:Screening for cystic fibrosis. 145 2


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