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)

Effects of trypsin and pronase on D-xylose uptake were studied on isolated frog sartorius muscle. Trypsin and pronase exerted insulin-like effects on the transport of sugar. The acceleration of xylose transport by insulin was reduced by a prior incubation of muscles with trypsin or pronase. The inhibition of insulin effect was not due to destruction of the hormone. Proteases had no effect upon the sugar transport stimulated by DNP or potassium contracture. A conclusion is made of the availability in the frog muscle membrane of some insulin receptor similar to that reported for muscle tissue and fat cells of mammals.
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PMID:[Effect of proteases on sugar transport in muscle tissue]. 30 25

1. All the porcine pancreas enzymes tested, regardless of their pI's were adsorbed on Amberlite CG-50 (a weakly acidic cation exchange resin) at pH 4, where the ion-exchange group (carboxyl group) is not dissociated. The adsorption is hardly influenced by ionic strength. 2. At pH 4, the adsorbed enzymes were partially eluted by organic solvents such as 50% propanol. 3. The adsorbed enzymes were effectively eluted by increasing the pH from 4 to 6. Trypsin (pI 10.5) was eluted before carboxypeptidase A (pI 4.5 AND 5.3) WITH 0.5 M acetate buffer, whereas the former enzyme was eluted after the latter enzyme with 0.2 M 3,3-dimethyl glutarate buffer. However, with either buffer, the elution order of enzymes was not always the same as the order of the pI's. 4. By a single Amberlite CG-50 column chromatography of porcine pancreas extracts, kallikrein, carboxypeptidase B, deoxyribonuclease, carboxypeptidase A, and trypsin were purified 100-fold, 16-fmately 13%. The purification procedures included treatment with protamine, ammonium sulfate fractionation, treatment with acid, DE-32 cellulose column chromatography, gel filtration on Sephadex G-100, preparative polyacrylamide gel electrophoresis, and affinity chromatography on 5' AMP-Sepharose 4B. The last procedure, affinity chromatography on 5' AMP-Sepharose 4B, was useful for the removal of other dehydrogenases. The enzyme which was homogeneous, as shown by polyacrylamide gel electrophoresis, had a molecular weight of about 92,000. The optimum pH was at 10.0 and isoelectric point at 5.2. The enzyme accepted both L-fucose and D-arabinose as substrate, but was specific for NAD+ as coenzyme. Km values were 0.15 mM, 1.4 mM, and 0.07 mM for L-fucose, D-arabinose, and NAD+, respectively. A single enzyme catalyzed the oxidation of L-fucose and D-arabinose, which had the same configurations of hydroxyl groups from C-2 to C-4. The reaction products obtained with L-fucose as substrate were L-fucono-lactone and L-fuconic acid. The L-fucono-lactone was an immediate product of oxidation and was hydrolyzed to L-fuconic acid spontaneously. This reaction was irreversible. Therefore, it is likely that L-fucose dehydrogenase is involved in the initial step of the catabolic pathway of L-fucose in rabbit liver.
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PMID:Hydrophobic-ionic chromatography. Its application to purification of porcine pancreas enzymes. 31 32

The amino acid sequence of the L-arabinose-binding protein of Escherichia coli B/r was determined by sequenator analyses of reduced and S-pyridylethylated L-arabinose-binding protein and fragments derived by chemical and enzymatic cleavage of the native protein. The fragments were the products of cleavage by cyanogen bromide. BNPS-skatole, hydroxylamine, mild acid hydrolysis, limited trypsin digestion, chymotrypsin subdigestion, and subdigestion with Staphylococcus aureus protease V8. The COOH-terminal sequence was determined using bovine carboxypeptidases A and B and amino acid analyses. The L-arabinose-binding protein was determined to contain 306 amino acid residues, the sequence of which is presented below.
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PMID:Amino acid sequence of the L-arabinose-binding protein from Escherichia coli B/r. 32 84

Bacteriocin-like substances were commonly produced by slow-growing Rhizobium japonicum and cowpea rhizobia on an L-arabinose medium. Antagonism between strains of R. japonicum was not detected in vitro; however, such strains were often sensitive to some bacteriocins produced by cowpea rhizobia. Inhibitory zones (2 to 8 mm from colony margins), produced by 58 of 66 R. japonicum test strains, were reproducibly detected with Corynebacterium nebraskense as an indicator. Quantitative production was not related to symbiotic properties of effective strains, since nine noninfective strains and one ineffective strain produced bacteriocin. Eight R. japonicum strains that did not produce bacteriocin nevertheless formed effective nodules on soybeans. R. japonicum strains that produced bacteriocin in vitro had no antagonistic effect on nonproducer strains during soybean nodulation. Under controlled conditions, a nonproducer (3I1b135) predominated over a bacteriocin producer (3I1b6) when inoculated at 1:1 and 1:9 ratios. Depending on the particular ratio, up to 38% of the total nodules formed were infected with mixed combinations. The bacteriocin(s) had a restricted host range and antibiotic-like properties which included the ability to be dialyzed and resistance to heat (75 to 80 degrees C, 30 min), Pronase, proteinase K, trypsin, ribonuclease, and deoxyribonuclease. R. japonicum strains representing genetic, serological, cultural, and geographic diversity were differentiated into three groups on the basis of bacteriocin production.
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PMID:Bacteriocin-like substances produced by Rhizobium japonicum and other slow-growing rhizobia. 57 16

Jejunal perfusion studies were performed to assess water, electrolyte, d-xylose, and d-glucose transport in 16 patients with chronic calcific pancreatitis (eight with and eight without steatorrhoea) and in 10 control subjects. The patients with steatorrhoea demonstrated significantly less xylose, water, and electrolyte absorption than patients without steatorrhoea and control subjects, when an isosmotic slaine-xylose solution was perfused. On the other hand, when an isosmotic saline-glucose solution was perfused, the patients with steatorrhoea absorbed significantly more glucose, water, and electrolytes than control subjects. Significant correlation was demonstrated between the absorption of xylose as measured by the segmental perfusion technique and the peak serum xylose level during perfusion as well as the five-hour urinary xylose excretion after a 25 g oral dose of xylose. The xylose absorption measured by small bowel perfusion also correlated significantly with pancreatic juice amylase and trypsin concentrations obtained during a standard pancreatic function test.
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PMID:Jejunal monosaccharide, water, and electrolyte transport in patients with chronic pancreatitis. 62 5

A series of variant lines that utilize multiple pentoses for growth in place of glucose have been isolated from an 8-azaguanine resistant line of Novikoff hepatoma cells (N1S167). These variants utilize for growth ribose, xylose, arabinose, and/or deoxyribose. The variants growing on pentose containing medium (a) exhibit a density dependent cessation of growth, (b) have a morphology change to a more flattened cell type, (c) become binucleated in the presence of cyto chalasin B, and (d) show an altered sensitivity to trypsin treatment.
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PMID:Pentose utilizing variants of Novikoff hepatoma cells: modification of growth and morphological properties. 85 67

The purity of horseradish peroxidase isoenzyme C was demonstrated using isoelectric focusing, polyacrylamide gel electrophoresis at two pH values and cellulose acetate electrophoresis at two pH values. The glycopeptides obtained upon trypsin digestion were isolated using the plant lectin, concanavalin A, and were resolved using paper electrophoresis. The carbohydrate content of the native peroxidase was 86% accounted for by the carbohydrate content of the glycopeptides thus suggesting little loss of carbohydrate during glycopeptide isolation and purification. In each of the seven glycopeptides isolated glucosamine was associated with asparagine, thus suggesting the carbohydrate chains are covalently bound to the peptide chain through N-glycosidic linkages. The purity of each glycopeptide was demonstrated by the sequential release of single amino acid residues by Edman degradation. As six glycopeptides had unique amino acid sequences, it was concluded that the carbohydrate prosthetic group was distributed in at least six units along the protein backbone. Five glycopeptides possessed the amino acid sequence about the point of carbohydrate attachment of Asn-X-(Ser, Thr) where X is any amino acid. The size of the carbohydrate units ranged from 1600 to 3000 daltons. The predominant carbohydrate residues in each glycopeptide were mannose and glucosamine with lesser and varying amounts of fucose, xylose, and arabinose. There was no apparent correlation of the carbohydrate composition with the amino acid sequence.
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PMID:The isolation and characterization of the glycopeptides from horseradish peroxidase isoenzyme C. 126 13

The nature of the primary signals important for the addition of xylose to serines on the core protein of the cartilage chondroitin sulfate proteoglycan has been investigated. The importance of consensus sequence elements (Acidic-Acidic-Xxx-Ser-Gly-Xxx-Gly) in the natural acceptor was shown by the significant decrease in acceptor capability of peptide fragments derived by digestion of deglycosylated core protein with Staphylococcus aureus V8 protease, which cleaves within the consensus sequence, compared to the similar reactivity of trypsin-derived peptide fragments, in which consensus sequences remain intact. A comparison of the acceptor efficiencies (Vmax/Km) of synthetic peptides containing the proposed xylosylation consensus sequence and the natural acceptor (deglycosylated core protein) was then made by use of the in vitro xylosyltransferase assay. The two types of substrates were found to have nearly equivalent acceptor efficiencies and to be competitive inhibitors of each other's acceptor capability, with Km = Kiapparent. These results suggest that the artificial peptides containing the consensus sequence are analogues of individual substitution sites on the core protein and allowed the kinetic mechanism of the xylosyltransferase reaction to be investigated, with one of the artificial peptides as a model substrate. The most probable kinetic mechanism for the xylosyltransferase reaction was found to be an ordered single displacement with UDP-xylose as the leading substrate and the xylosylated peptide as the first product released. This represents the first reported formal kinetic mechanism for this glycosyltransferase and the only one reported for a nucleotide sugar:protein transferase.
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PMID:Initiation of chondroitin sulfate biosynthesis: a kinetic analysis of UDP-D-xylose: core protein beta-D-xylosyltransferase. 190 43

The N-linked glycans from the 52/54-kDa medium protein and cell wall beta-fructosidase, two glycoproteins secreted by carrot suspension culture cells, were characterized. Carrot cells were labelled with [3H]glucosamine or [3H]fucose. The 52/54-kDa medium protein was isolated from the culture medium and beta-fructosidase from cell walls. The purified proteins were digested with trypsin and glycopeptides were isolated and sequenced. Glycans obtained from individual glycopeptides were separated by gel filtration chromatography and characterized by concanavalin A chromatography, by treatments with exoglycosidases and by sugar composition analysis. The 52/54-kDa medium protein and cell wall beta-fructosidase have one high-mannose-type glycan similar to those from yeast and animal glycoproteins. In addition, the 52/54-kDa medium protein has three complex-type and cell wall beta-fructosidase two complex-type glycans per polypeptide. The complex-type glycans isolated from individual glycosylation sites are fairly large and very heterogeneous. The smallest of these glycans has the structure [Xyl](Man)3[Fuc](GlcNAc]2Asn (square brackets indicating branching) whereas the larger ones carry additional sugars like terminal N-acetylglucosamine and possibly rhamnose and arabinose in the case of the 52/54-kDa medium protein and only arabinose in the case of cell wall beta-fructosidase. These terminal sugars are linked to the alpha-mannose residues of the glycan cores. The 52/54-kDa medium protein is secreted with large and homogeneous complex glycans, their heterogeneity originates from slow processing after secretion. The complex glycans from cell wall beta-fructosidase are processed before the enzyme is integrated into the cell wall.
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PMID:Heterogeneity of the complex N-linked oligosaccharides at specific glycosylation sites of two secreted carrot glycoproteins. 206 72

To investigate the pathophysiology of steatorrhea in primary biliary cirrhosis, the severity of steatorrhea, small bowel histology and function, cholestasis, exocrine pancreatic secretion and liver histology were studied. Twenty-four primary biliary cirrhotic patients had a quantitative stool fat collection, serum bilirubin and alkaline phosphatase and liver biopsies. From this group, ten had further studies: a small bowel biopsy (n = 7); a D-xylose test (n = 9); measurement of pancreatiobiliary concentrations and outputs after intravenous cholecystokinin (n = 10); essential amino acid perfusion of the duodenum (n = 9), and eating a test meal (n = 7). D-xylose absorption was normal, and only one patient had a minimal small bowel mucosal abnormality. Pancreatic lipase outputs in response to cholecystokinin were low in two primary biliary cirrhotic patients, but were greater than 10% of normal. Postprandial lipase outputs were normal except in one patient who had abnormal duodenal acidification. Mean enzyme outputs in primary biliary cirrhotic patients were normal in response to essential amino acid perfusion; but 6 had low lipase and 5 had low trypsin outputs which were associated with decreased bile acid outputs (p less than 0.03). Severity of steatorrhea was associated with reduced bile acid outputs and concentrations (r = 0.82; p less than 0.0001), degree of cholestasis (serum bilirubin; r = 0.88; p less than 0.001) and advanced histologic stages (p less than 0.005). Severe intraluminal bile acid deficiency combined with a submaximal intraluminal stimulus (essential amino acids) may be associated with decreased exocrine pancreatic secretion in primary biliary cirrhosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pathogenesis of steatorrhea in primary biliary cirrhosis. 241 48


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