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)

Digestion and absorption of protein were determined in ovine gastrointestinal tract with cerium-141 as an unabsorbed reference substance. Nitrogen flows changed little in rumen and reticulum, but in the proximal small intestine flows increased because of secretion of .9 g nitrogen per day per kg body weight. This secretion included trypsin, chymotrypsin, elastase, and carboxypeptidases A and B; maximal activity was in proximal segments of the small intestine and decreased with distance from the pylorus. Activity of chymotrypsin decreased more rapidly than that of trypsin. Amino acid flows reflected the influx of protein in the duodenum; absorption was approximately 55% in the terminal ileum. No major changes of proportions of individual amino acids were observed. Overall nitrogen absorption was 72.6% of which 6% was in the large intestine. The major soluble protein fraction in the gastrointestinal tract consisted of peptides with molecular weight 7,000 to 14,000 daltons. Soluble high molecular weight protein was observed only in rumen and duodenum. Low molecular weight peptides and amino acids accumulated only in the proximal small intestine. Solubilization of protein and breakdown of peptides of 7,000 to 14,000 molecular weight appear to be rate limiting for protein absorption in sheep.
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PMID:Digestion and absorption of protein along ovine gastrointestinal tract. 403 Nov 87

1. The action of trypsin, chymotrypsin and subtilisin on the adenosine-triphosphatase and actin-combining activities, as measured by viscometric means, of H-meromyosin were compared. 2. Subfragment 1 produced by prolonged tryptic digestion has a molecular weight of 129000. 3. The preparations isolated by gel filtration and actin combination were shown to be similar. 4. Subfragment-1 preparations possess appreciably higher adenosine-triphosphatase activities than H-meromyosin when related to total nitrogen. 5. Chromatographic and gelfiltration studies indicated that adenosine-triphosphatase activity is not distributed uniformly in all fractions of subfragment 1. 6. The Ca(2+)-activated adenosine triphosphatase of subfragment 1 was stimulated by thiol reagents in a similar fashion to myosin and H-meromyosin. 7. Subfragment 1 differed from myosin and H-meromyosin in that its adenosine triphosphatase was only slightly activated by Mg(2+) in the presence of actin. 8. A subfragment-1-like component was obtained by chymotryptic digestion of H-meromyosin. 9. The results obtained from enzymic and hydrodynamic studies and from amino acid analyses are compatible with the concept of one molecule of H-meromyosin giving rise to one molecule of subfragment 1 on proteolytic digestion.
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PMID:The biological activity of subfragment 1 prepared from heavy meromyosin. 422 74

Correlation of leukocyte typing with homograft survival suggests that HL-A typing of white blood cells reflects the histocompatibility factors of the kidney, yet some apparently well-matched kidneys are rejected. The latter results may, in part, reflect inadequacies of typing techniques, incomplete expression of HL-A factors on white blood cells as compared with the cells of the rejected organ, or isoantigens not shared with leukocytes. In this study the kidney cells and lymphocytes (from blood or nodes) of 14 individuals were typed for HL-A factors 1, 2, 3, 5, 7, 8, 9, and 12, and factors 4a and 4b by fluorochromasia cytotoxicity. Biopsied kidney cells were prepared with 0.25% trypsin and typed fresh, after varying periods in monolayer culture or after storage in liquid nitrogen, in all cases resulting in cells which were pleomorphic but uniform in reactivity. Reproducibility of lymphocyte typing was 99%, and of kidney cell typing, 93%. The 4a factor was detected on the lymphocytes but not the kidney cells of four individuals. HL-A7 and HL-A8, in contrast, were detected on kidney cells and not lymphocytes of four and three individuals, respectively. Results were consistent within the groups of individual sera used to detect each factor. The HL-A factors detected on both kidney cells and lymphocytes never resulted in more than two alleles at each genetic sublocus. Several examples of post-rejection sera have reacted with donor kidney cells but not with lymphocytes. Kidney cells may thus be useful in compatibility tests to aid in selection of donors for a retransplant. The ability to store donor kidneys by perfusion provides time to employ kidney cells for typing and in compatibility tests, and the use of a standard cytotoxic assay makes their routine use practical. Typing kidney cells as well as lymphocytes thus offers an approach to more complete and accurate HL-A phenotyping.
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PMID:Comparison of the HL-A phenotypes of lymphocytes and kidney cells determined by the fluorochromasia cytotoxicity assay. 554 Jan 66

An attempt was made to establish the number and characteristics of the enzymes in pancreatic juice that hydrolyze nitrogen- and phosphorus-free esters of fatty acids. For this purpose model compounds were hydrolyzed by lyophilized rat pancreatic juice under conditions that accelerated or inhibited the reactions. Although it is not established with certainty, it is suggested that three enzymes are responsible for the hydrolysis of fatty acid esters. The first enzyme is glycerol-ester hydrolase (EC 3.1.1.3) or lipase. This enzyme hydrolyzes water-insoluble esters of primary alcohols. The reaction occurs at an oil/water interface and is inhibited by bile salts at pH 8. The enzyme is relatively stable at pH 9, but unstable at pH 4. It has a broad pH optimum between 7.5 and 9.5. The second enzyme hydrolyzes esters of secondary alcohols and of other alcohols as well. It has an absolute requirement for bile salts and has a pH optimum at about 8. The enzyme is unstable in pancreatic juice when maintained at pH 9, probably due to the action of trypsin. It may be identical with sterol-ester hydrolase (EC 3.1.1.13). The third enzyme hydrolyzes water-soluble esters. It too has an absolute requirement for bile salts, although a smaller amount is necessary for maximum activity. This enzyme also is unstable at pH 9, but can be differentiated from the preceding enzyme by its stability at pH 4 and its pH optimum of 9.0. Carboxylic-ester hydrolase (EC 3.1.1.1) is not found in pancreatic juice, although it is present in pancreatic tissue.
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PMID:Carboxylic ester hydrolases of rat pancreatic juice. 596 95

Red cells, trypsin-treated to render them more agglutinable and coupled with antiglobulin reagents, may be preserved by droplet freezing in liquid nitrogen. A 2% cell suspension in 0.45% w/v sodium chloride, 5% w/v sucrose and 10% w/v dextran 40 was used. After thawing the frozen pellets in phosphate-buffered saline at 40 degrees C, more than 80% cell recovery was obtained. Sheep and ox red cells preserved in this way were as satisfactory in antiglobulin and in reverse passive haemagglutination tests as unfrozen indicator red cells. Trypsin-treated human red cells coupled with anti-IgE could likewise be frozen and on reconstitution used to assay IgE in human serum. Reconstituted ox red cells were slightly less efficient in rosetting than cells which had not been frozen.
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PMID:Cryopreservation of antibody-coupled red cells for use in immunoassays. 618 15

In healthy volunteers (n = 10), the exocrine pancreatic secretion was studied after intragastric administration of a peptid solution which corresponded to the nitrogen component of a commercially available peptid diet, and of a solution of the analogous amino acids. Both test solutions were emptied out of the stomach in the same time interval and evoked a comparably high pancreatic secretion of volume, amylase, lipase, trypsin and chymotrypsin. These findings are discussed in regard to recommendations to apply elemental diets for treatment of complicated pancreatitis.
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PMID:[Effect of the nitrogen components of a peptide diet and the analogous amino acids on pancreatic secretion in the human]. 618 97

Raw and heated soy flour and casein diets were compared in rats, pigs, and monkeys with respect to growth, pancreatic changes, fecal trypsin, and nitrogen digestibility. Cholecystokinin injection was compared to feeding raw soy flour and casein in rats and casein in pigs. Several soy protein preparations were fed to rats and monkeys. Neither raw soy flour nor any other soy product produced pancreatic enlargement in pigs or monkeys. Casein and heated soy flour performed similarly. By comparison, other effects of raw soy flour were as follows. Growth was depressed 60% in rats and 84% in pigs, but not at all in monkeys. Nitrogen digestibility was depressed 5, 45, and 9% in rats, pigs, and monkeys, respectively. Pancreatic DNA, RNA, and protein levels were unchanged in monkeys fed raw soy flour. In rats, RNA per milligram pancreas was increased 40%, in pigs 20%. Pancreatic protein was decreased 7% in pigs and increased 47% in rats. Changes in pancreatic trypsin, chymotrypsin, lipase, and amylase were dissimilar in the three species. Fecal trypsin was elevated 300-400% in rats, and decreased approximately 50% in pigs and monkeys. Cholecystokinin injections in pigs and rats produced changes both quantitatively and qualitatively different from those seen with raw soy flour. Feeding of heated soy flour or soy protein isolates was comparable to feeding casein in all three species, and produced no deleterious effects.
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PMID:Effects on the monkey, pig and rat pancreas of soy products with varying levels of trypsin inhibitor and comparison with the administration of cholecystokinin. 618 59

Ileostomized rats were fed diets with different fiber content. The addition of 5% pectin to the diet caused an increase in the wet weight, fat content, amylase activity per gram, and lipase output of the ileostomy evacuates. Twenty percent wheat bran in the diet increased weight, fat and nitrogen content, and trypsin output of the evacuates. In normal rats pectin added to a meal containing 3H-labeled triolein increased the isotope activity of the feces, indicating an impaired fat absorption. In rats operated on with occlusion of the pancreatic ducts with a tissue glue, the fat absorption was, however, not significantly affected by pectin. The results of the study show that fiber can cause a change in the intestinal enzymatic milieu of ileostomized rats and can cause steatorrhea, which can be explained, at least partly, by malabsorption.
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PMID:Effects of dietary fiber on pancreatic enzyme activities of ileostomy evacuates and on excretion of fat and nitrogen in the rat. 620 Sep 23

Vibrio alginolyticus produces an extracellular collagenase which requires specific induction by collagen or its high-molecular-weight fragments. Peptone also induces collagenase during the late exponential and early stationary growth phases. The peptone inducers have been shown to have a broad molecular weight range between 1,000 and 60,000. The peptone inducers supported slow growth of V. alginolyticus when supplied as the sole nitrogen source in minimal medium. Digestion of the peptone inducers with purified V. alginolyticus collagenase resulted in a decrease in their inducing ability, whereas digestion with trypsin or alpha-chymotrypsin did not. This indicated that induction by the inducers required the presence of collagenase-sensitive bonds. Prolonged digestion of the inducers with collagenase did not completely eliminate the inducing ability of the inducers. The peptone inducers acted as inhibitors of collagenase. A minimal medium induction system has been developed which involves resuspending cells at high density in a medium containing succinate, (NH(4))(2)SO(4), KH(2)PO(4), and the peptone inducer. Cells grown in minimal medium induce earlier than cells grown on peptone, Casamino Acids, or tryptone. Collagenase production was shown to occur for 30 to 60 min in the presence of rifampin at levels which completely inhibit the incorporation of [(3)H]uracil into trichloroacetic acid-precipitable material. Chloramphenicol completely and immediately abolished collagenase production, which together with labeling studies has confirmed that collagenase production involves de novo synthesis of the enzyme. Both glucose and Casamino Acids repressed collagenase production, although synthesis of the enzyme continued for 30 to 60 min after their addition. The repression of collagenase production by glucose and Casamino Acids was more severe than the inhibition of enzyme formation due to addition of rifampin.
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PMID:Peptone induction and rifampin-insensitive collagenase production by Vibrio alginolyticus. 624 22

Plasminogen is present in the cornea andcan be activated to plasmin by plasminogen activator. Plasmin is able, in turn, to activate latent collagenase. This system could initiate and perpetuate the collagen degradation of corneal ulceration. This report details evidence for such a system in the cornea. Plasmin has been found to activate latent collagenase from organ cultures of ulcerating rabbit corneas and from fibroblast cultures derived from such corneas. As in the case of activation by trypsin, activation by plasmin results in the conversion of the 40,000 MW latent form to an active species of 23,000 MW. Explants of normal or alkali-burned, ulcerating corneas demonstrated plasminogen-dependent lysis of fibrin clots; frozen sections of such corneas demonstrated that lysis begins in the superficial stroma near the periphery of the cornea. Multiply freeze-thawed ulcerating corneas, but not normal corneas, showed initial lysis, not peripherally but at the ulcer region containing polymorphonuclear leukocytes. The fact that the peripheral lytic pattern existed in corneas that were obtained from eyes prefrozen in liquid nitrogen before excision of the corneas would suggest that plasminogen activator is normally contained in cells in vivo and is not made only in response to tissue injury. There was no correlation between the location of blood vessels or the presence of the corneal endothelium and the plasminogen-dependent lysis. Plasminogen activator from the ulcerating cornea and from fibroblasts was characterized by sodium dodecyl sulfate--gel electrophoresis of its cleavage products of plasminogen. The activator cleaves plasminogen into heavy- and light-chain fragments similar to those produced from plasminogen by urokinase. Plasminogen activator activity was quantitated by a new assay that restricts diffusion of the enzyme to one dimension into a narrow bore tube. The addition of plasminogen daily to cultures of ulcerating corneas resulted in earlier rises of plasminogen activator, collagenase, and collagen degradation fragments in the culture media. Although total plasminogen activator levels were not increased by the addition of plasminogen to culture, levels of both collagenase and solubilized collagen were approximately doubled. It is concluded that the plasminogen activator--plasmin system might play an important role in the destruction of stromal matrix in corneal ulceration.
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PMID:Evidence for a role of the plasminogen activator--plasmin system in corneal ulceration. 625 12


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