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)

The different Escherichia coli envelope fractions (cell wall, cytoplasmic membrane, and DNA-envelope complex fragments) were isolated by free-flow electrophoresis and analyzed by sodium dodecylsulfate-acrylamide gel electrophoresis. The DNA-envelope complex fragments possess a specific protein (mol wt 80,000-90,000). Upon treatment with trypsin, this protein disappears and the complex breaks down, thus releasing DNA, cell wall, and cytoplasmic membrane. Disaggregation of the complex can also be achieved by high salt concentrations. Lysozyme treatment dissolves the murein layer within the complex but does not disaggregate the complex. From these and other results on the stability of the DNA-envelope complex, conclusions can be drawn about the possible linkage within the described envelope particles.
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PMID:Deoxyribonucleic acid-envelope complexes from Escherichia coli. A complex-specific protein and its possible function for the stability of the complex. 110 40

Rat liver microsomes incubated with [3H] puromycin in high salt buffer were digested with a mixture of protease, trypsin and chymotrypsin, in both the presence and absence of 1 % deoxycholate. Our observations revealed that the proteolysis of peptidyl puromycin labeled with [3H] puromycin was at least partially protected by the presence of microsomal membrane. Immuno-chemical analyses have further shown that most of the nascent NADPH-cytochrome c reductase in the microsomes was digested with the proteases while serum albumin was effectively protected from the digestion. It is thus proposed that NADPH-cytochrome c reductase synthesized on the membrane bound ribosomes is not transported to the vesicular cavity but directly to the outer surface of the microsomal membrane in a form which is accessible to the proteases.
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PMID:Localization of nascent NADPH-cytochrome c reductase in rat liver microsomes. 111 86

Human milk contains a bile salt-stimulated lipase in amounts that, at pH 6.5 and in the presence of bile salts, might account for a total hydrolysis of the milk triacylglycerols in less than 30 min. In the absence of bile salts the enzyme has no activity against milk fat or against emulsified trioleylglycerol. The primary bile salts sodium cholate and sodium chenodeoxycholate and their taurine and glycine conjugates, but not the secondary bile salt sodium deoxycholate or its taurine and glycine conjugates, caused a pronounced activation of the enzyme against emulsified trioleylglycerol. The lipase was stable at pH 3.5 and 37 degrees C for 1 hour. It was inactivated when incubated with trypsin or chymotrypsin at pH 6.5 but these inactivations were almost abolished in the presence of bile salts. High concentrations of pepsin slowly inactivated the enzyme at pH 4.0. The bile salt-stimulated lipase in human milk is thus stable enough to be active in the intestine, and it is present in high enough activity to contribute significantly to the hydrolysis of the milk triaclyglycerols in the intestine.
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PMID:Human milk lipases. III. Physiological implications of the bile salt-stimulated lipase. 114 84

The preparation of benzylated covalently cross-linked Sepharose 2B is described. Such gel was analyzed for its degree of substitution, and gels with three different degrees of substitution were used in chromatographic experiments with dextranase, alpha-amylase, lactate dehydrogenase, alpha-chymotrypsin and trypsin. Yields and chromatographic patterns for different eluting systems were determined. It was found that gradients combining an increase in ethylene glycol concentration with a decrease in salt concentration gave better results than did pure salt gradients. No denaturation was observed for dextranase or alpha-amylase, but the other enzymes tested were partly denatured. The most severe denaturation was observed for lactate dehydrogenase desorbed from the highest substituted gels, although the enzyme was highly active in the adsorbed state. The results and the use of amphophilic gels are discussed.
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PMID:Agarderivatives for chromatography, electrophoresis and gel-bound enzymes. IV. Benzylated dibromopropanol cross-linked sepharose as an amphophilic gel for hydrophobic salting-out chromatography of enzymes with special emphasis on denaturing risks. 115 15

The ability of aromatic tryptophyl and tyrosyl side-chain donors to form charge-transfer (CT) complexes with the acceptor 1-methyl-3-carbamidopyridinium chloride has been used to investigate the degree of exposure of these aromatic residues in denaturated proteins. The coplanar geometry of the CT complexes requires that virtually a full ring face of the donor be available for interaction with the acceptor, and the aromatic donor residues of lysozyme, trypsin, chymotrypsin, and the zymogens of the latter two enzymes do not appear to be wholly "exposed" in 6 M guanidine hydrochloride. Comparison of the CT proerties of the proteins with the corresponding properties of model complexes suggests that the incomplete exposure is due at least in part to statistical fluctuations in the continuously mobile, randomly coiled polypeptide chain which result in residues being alternately fully exposed and partly covered. Reduction and alkylation of the disulfide cross-links increase the apparent availability of the aromatic residues but the exposure is still less than that expected from a comparable mixture of tryptophan and tyrosine residues. Previous studies on the exposure of the aromatic residues of lysozyme and trypsin in aqueous salt solutions, when taken together with the present results, further suggest that there are two distinct kinds of surface environment possible on native proteins in solution. Some residues appear to be located in areas of the protein surface which are characterized by relatively fixed or stable local conformations, and have apparent CT association constants closely resembling these of comparable model complexes. Other residues may be located in a region where the protein conformation is flexible or continuously mobile, as evidenced by their smaller apparent association constants. It is probably significant that Trp-62 of lysozyme and Trp-215 of trypsin, both specificity site residues, appear to belong to the class of residues which can be considered as being in a flexible environment on the protein surface.
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PMID:Charge-transfer studies of the availability of aromatic side chains of proteins in guanidine hydrochloride. 117 11

Cortisol-binding protein was prepared and partially purified by (NH4)2SO4 fractionation and DEAE-cellulose column chromatography from 105,000 g supernatant fraction of cytoplasm in rat carrageenin granuloma, which is assumed to be one of the most appropriate experimental models of inflammation. The cortisol-binding protein in the inflammatous tissue, although similar to transcortine, was not transcortine itself. The binding protein was eluted at 0.12 M NaCl by DEAE-cellulose column chromatography with a shallow salt gradient. Sedimentation constant and dissociation constant of the binding protein were 4-5 S and 1.0 X 10(-9) M, respectively. Optimum pH for binding to cortisol was 8.0. Binding ability of the binding protein to cortisol was very sensitive to pronase E and trypsin but resistant to RNase. Specificity of the protein for binding other steroids revealed that 17beta-estradiol did not bind to the protein, while androstenedione and testosterone had one sixth as much affinity to the binding protein as that of cortisol. There was good a correlation between the amount of the binding protein in the inflammatory tissue and anti-inflammatory effect of cortisol. Namely, the maximum cortisol-binding ability was seen on a 5 day old granuloma which is the so called 'steroid sensitive stage'. Thereafter, the binding ability decreased with the increasing stage of granuloma.
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PMID:Cortisol-binding protein in the cytosol of rat carrageenin granuloma. 118 1

Rat liver 40S and 60S ribosomal subunits were treated with increasing concentrations of trypsin. The activity of both trypsin-treated subunits, when assayed for polyphenylalanine synthesis, progressively decreased, but the 60S subunits were inactivated at much lower trypsin concentrations than were the 40S ones. The sedimentation coefficients of trypsin-treated subunits were identical to those of control subunits when sucrose gradients containing 0.5 M KCl were used. When the sucrose gradients were prepared with a low salt buffer (80 mM KCl), dimer formation was observed with control subunits, but not with trypsin-treated ones. Two-dimensional gel electrophoresis analysis of the proteins extracted from trypsin-treated subunits revealed that all ribosomal proteins in the subunits were accessible to the enzyme. However, several proteins were more resistant to trypsin in compact subunits than when they were free or in unfolded subunits. Proteins of the 60S subunits were generally digested by lower trypsin concentrations than those of the 40S subunits. From the quantitative measurements of the undigested proteins, a classification of the proteins from both subunits according to their trypsin sensitivity was established. These results were compared with those previously obtained concerning ribosomal protein reactivity to chemical reagents.
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PMID:Study on mammalian ribosomal protein reactivity in situ. III. Effect of trypsin on 40S and 60S subunits. 122 23

CFY male rats anaesthetized with pentobarbital were used in different groups for inducing acute pancreatitis by the retrograde injection either of 1 mg elastase, 5 mg trypsin, 4 mg lysolecithin, 10 mg Na-taurocholate in 0.2 ml volume or of 0.3 m. sunflower oil. In each group laparatomized animals served for control. The animals with pancreatitis were treated either with 15 mug/b.w.kg/hour glucagon or with physiological saline for 72 hours. Twenty-four and 72 hours after inducing pancreatitis glucagon did not influence the significant fall in blood pressure elicited by the intraductal injection of trypsin or elastase or in the plasma calcium level in pancreatitis induced by trypsin or sunflower oil. Neither did glucagon affect the significant increase of plasma lipase activity in pancreatitis induced by trypsin or taurocholate. It also failed to reduce the 24-hour mortality rate and the extension of fat tissue necrosis in the abdominal cavity of pancreatitic animals. In contrast, glucagon treatment significantly reduced the amount of abdominal exudate associated with bile salt induced pancreatitis and, probably due to its pancreatic blood flow increasing effect, seemed to moderate the degree of tissue damage elicited in the pancreas by detergents such as taurocholate or lysolecithin.
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PMID:Glucagon treatment of experimental acute pancreatitis. 123 17

The effects of hyperglycemia on pancreatic, biliary, and gastric secretory responses to meals have not been hitherto quantified in man. In the present study seven normal volunteers were fed on two occasions a 500-ml liquid test meal containing fat and protein. During one of the meals the subjects were made acutely hyperglycemic with intravenous glucose, whereas in control experiments, each subject received intravenous saline in place of glucose. A jejunal perfusion method was used to measure pancreatic outputs of trypsin and biliary outputs of bile salts for 150 min after the meal; the same method was used to quantify indirectly the amount of acid secreted by the stomach in the 150-min period. Serum gastrins were also measured basally and at intervals after the meal. Hyperglycemia suppressed serum gastrin, gastric acid production, trypsin secretion, and bile salt output in response to the test meal.
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PMID:The effect of acute hyperglycemia on meal-stimulated gastric, biliary, and pancreatic secretion, and serum gastrin. 124 79

Acute haemorrhagic pancreatitis was induced in greyhound dogs by a bile salt/trypsin injection into the main pancreatic duct. Prostaglandin-like activity in the pancreatic venous blood, right atrial blood, and arterial blood was measured by bioassay. Activity rose significantly in the pancreatic venous blood of test dogs but not in controls. Chromatographic analysis of the peritoneal exudate from the dogs with pancreatitis showed high levels of prostaglandin E-like material (mean 43 ng/ml prostaglandin E2 equivalents). It seems likely that prostaglandins contribute to the induced pancreatitis.
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PMID:Prostaglandin release in canine acute haemorrhagic pancreatitis. 126 76


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