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:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Bilirubin can be coupled covalently to albumin by using water-soluble carbodi-imide as coupling reagent. The optimal specificity in the attachment of bilirubin to the high-affinity site on the albumin molecule was obtained by treating an albumin-bilirubin complex with carbodi-imide in low concentrations and for a short period. The product was reduced, carboxymethylated and digested with trypsin. By fractionation on Sephadex G-50 (superfine grade) a peptide fraction containing most of the bilirubin label was isolated. Further purification by paper chromatography gave one peptide, consisting of residues 240-258. The peptide containined a single lysine residue, 240, and had an intact disulphide bridge. The results indicate that bilirubin is bound to lysine residue 240 at its high-affinity site on human serum albumin.
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PMID:Lysine residue 240 of human serum albumin is involved in high-affinity binding of bilirubin. 65 55

The partially purified glucosyltransferase (GTF) fraction synthesizing primarily water-insoluble glucans, GTF-A, and the homogeneous fraction synthesizing water-soluble glucans, GTF-B, were utilized to assess the binding of GTF activity to the cell surface of Streptococcus mutans GS-5. Growth of the cells in either Todd-Hewitt broth or a chemically defined medium did not appear to affect the ability of the cells to bind either enzyme fraction. Heat inactivation of the cells did not singificantly reduce the interaction of the enzymes with the cells. Cell surface glucan molecules appear to be involved in GTF binding to the cells because: (i) dextranase or alpha-1,3-glucanase treatment of the cells markedly reduced enzyme binding; (ii) the inclusion of soluble dextrans in the binding assays reduced both GTF-A and GTF-B binding to the cells; and (iii) pretreatment of the cells or the GTF-B fraction with soluble dextrans before binding significantly reduced enzyme binding to the cells. In addition, enzyme binding appears to require a cell surface protein component because Pronase, but not trypsin, treatment of cells reduced enzyme binding. Furthermore, the removal of a portion of the cell surface GTF-glucan complex with 3 N NaCl appears to provide additional binding sites for the enzymes. These results are interpreted in terms of the mechanism of the conversion of extracellular GTF to the cell-associated form.
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PMID:Interaction of glucosyltransferase with the cell surface of Streptococcus mutans. 66 17

To assess the effects of magnesium chloride or magnesium sulfate on the release of cholecystokinin from the duodenum, outputs of trypsin and bilirubin were quantified during perfusion of the duodenum with isotonic solutions of these salts. Net intestinal water transport was also quantified. The results suggest that magnesium ion in the duodenum is a relatively weak stimulus to the pancreas and gallbladder, an action not augmented by the concomitant presence of the sulfate ion. As determined by this human bioassay method, magnesium is a weak stimulant to cholecystokinin release. Furthermore, magnesium chloride inhibits net jejunal water absorption and magnesium sulfate is even more potent, promoting net water secretion, effects which cannot be entirely attributed to cholecystokinin release.
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PMID:Pancreatic, gallbladder, and intestinal responses to intraluminal magnesium salts in man. 67 2

An inhibitor of papain and other SH-proteases was purified 520-fold from human epidermis extracts by acetone fractionation, heat treatment, papain-Sepharose affinity chromatography, and Sephadex G-50 chromatography. The purified inhibitor had a molecular weight of 12,600 and contained no hexose, as tested by the anthrone reaction. The inhibitor survived in a boiling water bath, in 5% trichloroacetic acid, 20 mM Na3PO4 (pH 12.1) and 4 M NH4OH (pH 11.9). By isoelectric focusing 2 major activity peaks with pI's of 4.6 and 4.8, and a minor peak with a pI of 4.9 was fractioned, and 3 corresponding protein bands were seen after analytical isoelectric focusing. Immunization of rabbits with the purified inhibitor yielded a highly specific anti-inhibitor serum. The purified inhibitor inhibited papain, ficin, human cathepsins B and C, and slightly inhibited bromelain. No inhibition of serine proteases (bovine trypsin and chymotrypsin A, porcine elastase) or an acid protease (human cathepsin D) was observed. Evidence was obtained that the inhibitor formed a complex with both dithiothreitol-activated papain and enzymatically inactive mercuripapain.
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PMID:Purification and some characteristics of the human epidermal SH-protease inhibitor. 68 77

A method for the enrichment of live thyrotrophic pituitary cells is described. Pituitary glands of young male rats were removed into Earle's solution and dispersed in a 0.1% trypsin solution containing 0.5% bovine serum albumin, pH 7.2. Nylon fibres (25 microgram) were used for the separation of the thyrotrophic cells, by stringing them across a plastic frame which fitted a plastic Petri dish containing the cell suspension. The fibres were washed with light petroleum (b.p. 60--80 degree C) and carbon tetrachloride, hydrolysed with 3 M-HCL for 30 min at room temperature and washed with distilled water and phosphate-buffered saline (pH 7.2). The fibres were treated with thyrotrophin releasing hormone (TRH) alone or in the presence of soluble carbodiimide solution. After incubation for 1 h at room temperature, the fibres were transferred to a new Earle's medium and cells were released from the fibres by plucking them with a needle. The separated thyrotrophic cells were identified by radioimmunoassay and by electron microscopy. Using the above-mentioned methods, enrichment of thyrotrophic cells was obtained. Thus, the amounts of TSH, prolactin, LH and GH released, during 2 h of incubation, by 1.5 x 10(6) unseparated cells were 6.8 +/- 0.65, 4.1 +/- 0.47, 4.8 +/- 0.52 and 5.2 +/- 0.68 microgram respectively, while the same number of purified thyrotrophic cells released 76.1 +/- 0.42, 1.2 +/- 0.3, 0.6 +/- 0.35 and 1.6 +/- 0.22 microgram of the same hormones (means +/- S.E.M.).
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PMID:Separation of rat pituitary thyrotrophic cells. 68 67

Pollens release enzymes when they are dropped into water. Orchard Grass extracts were tested by two methods. The Api-Zym System determined 19 enzymes and colorimetric amounts of Leucine Aminopeptidases, Acid phosphatase and trypsin. These were compared with RAST inhibition assays. A good correlation was shown between the techniques. Thus the enzyme dosage may be useful for the standardization of pollen extracts.
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PMID:Enzyme determination and RAST inhibition assays for orchard grass (Dactylis glomerata): a comparison of commericial pollen extracts. 68 10

Previously, a proteolipid that can bind glutamate with high affinity has been isolated from pig heart mitochondrial membranes. A final affinity chromatography on gamma-methylglutamate-albumin coreticulated on glass fiber was necessary. This procedure includes long dialysis steps which tend to denature the high-glutamate affinity proteolipid. Here is described a new method of isolation which avoids long dialysis steps and yields greater amounts of the high-glutamate affinity proteolipid. The binding of glutamate or aspartate on high-glutamate affinity proteolipid has been studied by gel filtration, by equilibrium dialysis or by a new procedure of rapid centrifugation based on the insolubility of high-glutamate affinity proteolipid in water. The latter method permits the detection of low and high affinity sites for glutamate with a Kd 60 mM and 55 muM, respectively. Among a series of analogues, aspartate appeared to be the best competitor: Kd = 30 muM and two Ki values, 0.37 mM (at high glutamate concentration) and 3.8 muM (at low glutamate concentration). High-glutamate affinity proteolipid binds 0.4 nmol of glutamate but only 0.1 nmol of aspartate per mg protein. The sites for glutamate and aspartate appear to be different but interdependent. In the presence of high-glutamate affinity proteolipid, externally added glutamate stimulated the efflux of aspartate from preloaded liposomes. High-glutamate affinity proteolipid contains cardiolipin, phosphatidyl choline and phosphatidyl ethanolamine the distribution of which is different from that of the inner membrane. The effects of various phospholipases, trypsin, and thiol reagents were studied on the binding of glutamate. High-glutamate affinity proteolipid binds 9 nmol N-ethylmaleimide per mg protein but only 6.1 nmol in the presence of glutamate. The dissociation of high-glutamate affinity proteolipid caused by thiol reagents yielded a soluble protein fraction with higher affinity for glutamate. Electrophoresis and an immunological approach allowed the detection and titration of the glutamate dehydrogenase and aspartate aminotransferase present in high-glutamate affinity proteolipid in inhibited forms, the latter being 26-fold more concentrated than the former.
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PMID:Glutamate transport in pig heart mitochondria. Binding and structural properties of high-glutamate affinity proteolipid: reconstitution studies. 68 5

1. Chloroplasts inhibited by incubation with hydroxylamine in the light exhibit a low fluorescence yield upon illumination in the presence of dithionite sufficient to completely reduce the primary acceptor, Q. In the absence of magnesium ions, the fluorescence yield is the same as in control chloroplasts, suggesting that the reason for the low yield is a defect in the mechanism by which Mg2+ enhances the fluorescence. These chloroplasts were previouly shown to contain only low potential (Em7.8 = +80 mV) cytochrome b-559 (Horton, P. and Croze, E (1977) Biochim. Biophys. Acta 462, 86-101). 2. In Photosystem II particles, in heat-treated chloroplasts and in trypsin-digested chloroplasts, high potential cytochrome b-559 is absent and the variable fluorescence yield is again low. 3. Peas grown under intermittent light contain only one-fifth of the content of high potential cytochrome b-559 seen in fully greened plants, yet show high rates of water to methyl viologen electron transport. Aquisition of the high potential cytochrome b-559 accompanies synthesis of chlorophyll b, the onset of Mg-stimulated fluorescence and an increased variable yield of fluorescence. A similar correlation was seen during greening of dark-grown barley. 4. It is proposed that the high potential state of cytochrome b-559 is due to the same membrane properties which allow cation enhanced variable fluorescence, so that the presence of low potential cytochrome b-559 is accompanied by a decrease in variable fluorescence yield.
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PMID:Interactions between photosystem II components in chloroplast membranes. A correlation between the existence of a low potential species of cytochrome b-559 and low chlorophyll fluorescence in inhibited and developing chloroplasts. 68 9

Two heifers were implanted with 300 mg of the radiolabeled anabolic steroid, trenbolone acetate (TBA). After a 60 day slaughter and a 60 day removal followed by 76 day slaughter, total 3H-content in various tissues was 0.5--25 ng/g equivalents of TBA. Radioimmunoassay of the tissues showed that only 1--5% of the total residue present was TBA, its main metabolite trenbolone (TBOH), and TBOH glucuronide, plus up to 5% of other organic-soluble material. Of the radioactivity remaining about half was directly water-soluble, and the insoluble residue could be made water-soluble by treatment with the proteolytic enzymes pepsin and trypsin. These 2 portions were purified with Sephadex G-25 to give a low and high molecular weight fraction. Raney nickel reduction of sulfur bonds in either fraction released up to 50% of radioactivity into the organic phase. TLC showed that the latter contained 2 components which had characteristics similar to TBOH and its metabolites, and thus were at least partly drug-related metabolites. In vitro experiments with bovine liver also showed a small but definite protein binding. It is proposed that in dealing with these covalently bound residues, priority be given to the reactive drug intermediate and the type of binding to macromolecules rather than to the presence of the bound residue itself.
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PMID:Trenbolone acetate: experiences with bound residues in cattle tissues. 72 40


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