Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Exocrine pancreatic secretion was studied in the conscious, fistulated pig before and after (i) intravenous glucose injection and (ii) intravenous injections of intestinal mucosae obtained from pigs adapted to a high-starch diet and taken 30 and 60 min after the beginning of a meal of the same diet. Within 30 min after it was injected, the glucose inhibited pancreatic juice volume (--45.4 p. 100; P less than 0.001), total protein output (--54.2 p. 100; P less than 0.001) and specific amylase activity (--15.8 p. 100;P less than 0.001). Specific chymotrypsin activity increased (+ 5 p. 100; P less than 0.1), while that of lipase was not affected. On the contrary, the intravenous injection of intestinal mucosae increased pancreatic juice volume (greater than 49 p. 100; P less than 0.01), total protein output (greater than 55 p. 100; P less than 0.01) and specific amylase activity (greater than 33 p. 100; P less than 0.001), whilst specific lipase activity was inhibited (less than 8 p. 100; P less than 0.01). Specific chymotrypsin activity was unmodified. It is suggested that the duodenal mucosa may play a role in pancreatic enzyme adaptation to the diet; the possible mechanisms involved in this process are discussed.
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PMID:[The role of the duodenal mucosa in the adaptation of pancreatic alpha-amylase to the diet in the pig]. 618 82

The effects of intravenous glucose perfusion were studied in the pancreatic juice of fistulated pigs. Perfusions were performed either discontinuously for 3 hrs in the fasted or for 6 hrs a day over 6 days in the fed animal. Pancreatic juice volume, total proteins and total activities of chymotrypsin, amylase and lipase were always significantly lowered by glucose given intravenously. Amylase seemed to be the most inhibited of the three enzymes studied. It appeared that prolonged intravenous glucose perfusion could not reproduce in the pig the pancreatic amylase adaptation seen after oral administration of glucose.
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PMID:[Effects on exocrine pancreatic secretion in swine of the prolonged intravenous administration of glucose: application to the study of dietary adaptation mechanisms]. 618 93

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

The binding of Candida albicans yeast cells to human fibronectin (Fn), a major glycoprotein of mammalian cells, was studied using an in vitro assay. Adherence was quantitated in microtiter dishes coated with Fn to which radiolabeled yeast cells were added. Under optimum conditions of the assay, i.e., 1 mM CaCl2 and 70 micrograms Fn protein, approximately 40% of the radiolabeled yeast cells adhered to the Fn. Adherence to Fn was greater at 30 degrees C than at 4 degrees C and was greater with viable yeast cells than with heat-killed cells. Candida albicans (two strains) and C. tropicalis adhered to Fn to a greater extent than C. pseudotropicalis, C. krusei, or Saccharomyces cerevisiae. Pretreatment of C. albicans with chymotrypsin, pronase, or papain, but not pepsin, decreased adherence to Fn. Blocking experiments using mannan, sugars, or amino sugars were carried out by preabsorbing the Fn with each of the above-mentioned compounds. Candida mannan blocked adherence of C. albicans to Fn. The mannan effect was dose dependent. However, adherence of C. albicans to Fn was not significantly reduced by mannose, glucose, or several other sugars. The role of FN as a receptor for the binding of C. albicans yeast cells to buccal and vaginal epithelial cells was investigated also using an in vitro assay. We determined, using indirect fluorescent antibody techniques, that both buccal and vaginal epithelial cells possessed Fn. In addition, yeast cells, when pretreated with Fn, showed reduced adherence with buccal and vaginal cells when compared with nontreated cells. These studies may indicate a role for Fn in the adherence of C. albicans to buccal and vaginal epithelial cells.
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PMID:In vitro binding of Candida albicans yeast cells to human fibronectin. 637 Mar 99

Six pigs, initially of 35 kg mean live weight, were each fitted with a re-entrant cannula. This was formed on either side of a short pouch of duodenum into which the pancreatic duct opened and which contained a simple cannula linked to the centre of the re-entrant cannula. Each pig received two diets: diet A was based on wheat starch, sucrose and casein, while diet B was based on barley and soya-bean meal. The diets were given in equal amounts at 12 h intervals. Digesta and pancreatic juice were collected continuously during three 12 h periods for each pig on each diet. Mean duodenal output: dietary intake values for diets A and B respectively were: digesta 1.80, 2.86; dry matter 1.05, 1.03; nitrogen 1.05, 1.06; trichloroacetic acid (TCA)-soluble N 7.69, 9.10; glucose 0.97, 0.89. For diet A the proportion of TCA-soluble N in total N rose from 13 to 50% during 12 h, while it was approximately 50% throughout 12 h for diet B. Mean total pepsin (EC 3.4.23.1) activities (units/24 h) were 760449 (diet A) and 1 466 571 (diet B). Salivary and gastric secretions were calculated to be approximately 4 and 8 kg/24 h for diets A and B respectively. Mean flows in pancreatic juice (g/24 h) for diets A and B respectively were: juice 1204, 2182; protein 10.94, 12.10; N 1.98, 2.14; ash 9.46, 17.31; sodium 3.88, 6.91; potassium 0.23, 0.54; calcium 0.031, 0.046; phosphorus 0.024, 0.026. Mean total enzyme activities (units x 10(-3)/24 h) for diets A and B respectively were: trypsin (EC 3.4.21.4) 138, 114; chymotrypsin (EC 3.4.21.1) 84, 84; carboxypeptidase A (EC 3.4.2.1) 5, 4; carboxypeptidase B (EC 3.4.2.2) 15, 17; amylase (EC 3.2.1.1) 1061, 981. It was calculated that the minimum amount of endogenous N from saliva and gastric secretion was 0.3-0.6 g in 24 h. This assumes no absorption of N occurred anterior to the duodenal cannula.
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PMID:Studies on gastric digestion of protein and carbohydrate, gastric secretion and exocrine pancreatic secretion in the growing pig. 640 23

Synthase D and synthase I of high specific activity have been isolated from rabbit liver, with subunit Mr = 78,000 and 85,000, respectively. Minor bands of Mr = 78,000 and 71,000 were also observed, and these were shown to be proteolytic products containing synthase activity. Incubation with trypsin resulted in no activity changes, but there was a conversion of synthase I to the Mr = 78,000 species. Incubation with chymotrypsin produced no change in total synthase activity, but both enzymes were converted to the Mr = 71,000 species. Synthase I, after chymotrypsin treatment, became dependent on glucose-6-P for activity. Kinetic studies indicated that the chymotrypsin-treated synthase D and synthase I were not the same species. Synthase D contained 5.7 mol of alkali-labile phosphate/subunit and synthase I, 2.9 mol/subunit. With trypsin treatment there was little loss of phosphate from synthase. With chymotrypsin treatment, there was a loss of 3.1 and 1.5 mol of phosphate/subunit from synthase D and I, respectively. Some conversion to synthase I still occurred when chymotrypsin-treated synthase D was incubated with crude extract, suggesting that the phosphates which remained were still removable by synthase phosphatase. The presence of additional alkali-stable phosphates was indicated when the synthase samples were ashed. The total phosphates were 17.3 mol/subunit for synthase D and 13.4 mol/subunit for synthase I. Our results indicate that the liver synthase enzymes are highly phosphorylated and extremely susceptible to endogenous and exogenous proteolysis. The alkali-labile phosphates are distributed in chymotrypsin-sensitive as well as chymotrypsin-insensitive sites. Both sites are involved in the conversion of synthase D to synthase I.
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PMID:Endogenous phosphates on liver glycogen synthase D and synthase I. Studies on the number and location. 641 4

Dehulled seeds from Cucumeropsis Mannii Naudin mainly consist of lipids (40.3%) and proteins (34.5%). Carbohydrates, minerals, and water amount to 16.5, 3.7, and 5.9%, resp. From this composition a caloric value of 2 190 kJ/100 g is calculated. The major component of the oil linoleic acid (57.9%). Short-chain fatty acids are absent. All important macro and micro nutrient elements are present in sufficient amounts for human nutrition. The seeds are rich in vitamin E and in niacin (30.8 mg/100 g and 14.3 mg/100 g. resp.). Consumption of 100 g dehulled seeds covers the daily requirement of essential fatty acids, vitamin E and essential amino acids--methionine excepted. Besides starch (14.3 g/100 g) sucrose (1.14 g/100 g), raffinose (0.42 g/100 g) and stachyose (0.41 g/100 g) as well as traces of glucose and fructose are present. The proteins extracted with various solvents (H2O, 0.1 M KCl-, 0.1 mM K3PO4-, and 0.5% SDS-solution) are studied by amino acid analysis. SDS-electrophoresis and isoelectric focusing. Molecular weights of these proteins are between 5,000 and 80,000 daltons with the fraction between 20,000 and 35,000 predominating. The seeds exhibit weak inhibition of trypsin and do not inhibit alpha-chymotrypsin.
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PMID:[Chemical composition of seeds from Cucumeropsis mannii Naudin and their suitability as food]. 662 67

Bovine band 3 in membrane-bound and solubilized states was digested with chymotrypsin, trypsin, and papain. Bovine band 3 in red blood cells was fragmented by the proteases in a 5 mM NaH2PO4-Na2HPO4 buffer containing 0.3 M glucose, pH 8.0, but not in a 5 mM NaH2PO4-Na2HPO4 buffer containing 0.15 M NaCl, pH 8.0, in which human band 3 is cleaved by chymotrypsin and papain. When compared with the known data for human band 3, however, major fragments of bovine band 3 derived from intact cells, inside-out vesicles and unsealed ghosts were similar to those of human band 3, except that tryptic fragments were formed on the extracellular attack. The results suggest that bovine band 3 adopts a quite similar molecular arrangement in the membrane to in the human case. However, it was strongly suggested by molecular weight evaluation of fragments that the only detectable water-soluble 38,000-39,000 dalton fragment does not account for the entire hydrophilic pole of the band 3 molecule exposed in the cytoplasmic region of the membrane. When isolated band 3 was treated with the enzymes in a 2% solution of nonaethyleneglycol n-dodecyl ether, the major product was indistinguishable on sodium dodecyl sulfate-gel from the water-soluble fragment of the cytoplasmic domain origin of band 3. This fragment lost its resistance to further enzymatic degradation when treated with dimethylmaleic anhydride, thus band 3 oligomers were converted into their monomers. The chymotryptic 38,000 dalton water-soluble fragment obtained in nonaethyleneglycol n-dodecyl ether solution was a subfragment of a 50,000 dalton piece which was produced in a 2% solution of deoxycholate after chymotrypsin treatment of band 3.
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PMID:Proteolytic digestion of band 3 from bovine erythrocyte membranes in membrane-bound and solubilized states. 674 85

A study was made of the influence of the Maillard reaction in proteins on their digestibility by pepsin, trypsin, and chymotrypsin. The model substrates were obtained by heating bovine serum albumin (BSA) and beta-lactoglobulin (BLG) with glucose for the preset period of time at 50 degree C. The rate of proteolysis by alkaline proteolytic enzymes was measured by the autotitration technique, whereas pepsin activity was determined by fluorometry. An evidence was obtained that digestibility by trypsin and chymotrypsin of BLG-glycose decreased, while the amount of protein bound carbohydrate increased. In the case of BSA, the incubation with glucose led at first to an insignificant lowering of digestibility by these two enzymes whereupon the protein resistance decreased. Thermal processing of both BLG and BSA in the absence of glucose led to a distinct growth of digestibility as compared to the native forms of proteins. As to pepsin, the authors failed to find any decrease in the digestibility of the Maillard compounds. It was revealed that the Maillard reaction in proteins had different effects on digestibility of different protein substrates by different proteolytic enzymes.
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PMID:[Effect of Maillard protein modification on protein resistance to hydrolysis by digestive proteinases]. 679 55

Spermine and spermidine enhanced the binding of hexokinase isoenzyme type II to mitochondria, both of which were prepared from Ehrlich-Lettre hyperdiploid ascites tumor cells, at much lower concentrations than Mg2+. Chymotrypsin-treated hexokinase II could not bind to the mitochondrial membrane in the presence of either spermine or Mg2+, indicating that the effect of spermine is not a nonspecific action, since the treatment of chymotrypsin cleaves only the region essential for the binding without any significant effect of the catalytic activity. Both spermine and Mg2+ antagonized the glucose 6-phosphate-induced release of mitochondria-bound hexokinase, and promoted the binding of the solubilized hexokinase II even in the presence of glucose 6-phosphate. However, inhibition of the activity of soluble hexokinase by glucose 6-phosphate was not reversed by spermine and Mg2+. Hexokinase II rebound to mitochondria with spermine and Mg2+ produced glucose 6-phosphate using ATP generated inside the mitochondria, and no difference was observed between the spermine- and Mg2+-rebound systems. Significance of the binding of hexokinase to mitochondria, especially with polyamines, is discussed with reference to high glycolytic rate in tumor cells.
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PMID:Polyamines stimulate the binding of hexokinase type II to mitochondria. 688 95


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