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:3.4.21.1 (chymotrypsin)
10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Chymotrypsin inactivation of lysophosphatidic acid acyltransferase activity in detergent-disrupted rat liver microsomes, but not in intact microsomes, falsely indicated a lumenal location for the enzyme. Inhibition by several other proteases in the absence of detergent showed that lysophosphatidic acid acyltransferase activity is located on the cytoplasmic surface of microsomes. Chymotrypsin inactivation did not occur in vesicles disrupted by nitrogen cavitation unless deoxycholate was present, suggesting that deoxycholate exposes a cryptic chymotrypsin cleavage site. Criteria for localization of lumenal microsomal enzymes should include studies using several proteases and/or employ more than one method of microsomal disruption.
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PMID:Enzyme asymmetry in hepatic microsomal vesicles. Criteria for localization of lumenal enzymes with proteases. 624 80

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

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

The trypsin inhibitor TI-2 produced by Streptomyces griseus Cal in a medium, containing beef extract and peptone as the nitrogen source, was purified by ammonium sulfate precipitation and gel filtration. Amino acid analysis showed that it contained hydroxyproline and carbohydrate whereas tyrosine, tryptophan, and cystine were absent. The composition of the inhibitor protein thus showed a similarity to collagen. Growth of the organism in a medium with gelatin as the sole nitrogen source resulted in the production of the same TI-2 inhibitor. Incubation of gelatin with either concentrated culture filtrate, trypsin, or chymotrypsin also yielded trypsin inhibitors. The product isolated from the in vitro incubation of gelatin with trypsin appeared to be the same as TI-2. To the author's knowledge, this is the first report that peptides obtained by enzymic hydrolyses of gelatin are trypsin inhibitors.
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PMID:Studies on TI-2 trypsin inhibitor of Streptomyces griseus. 642 69

A protein-free diet is often used in animal experimentation to estimate the amount of total endogenous nitrogen secreted by the organism. To test the validity of this technique, we carried out a study on pigs describing the short-term (8-day) effect of a protein-free diet on exocrine pancreas nitrogen secretion; this nitrogen was considered as representative of total endogenous nitrogen. After 11 pigs had been adapted to a balanced diet (14% protein), they were chronically fistulated in the pancreatic duct and duodenum. Pancreatic secretion and its various parameters (volume, total protein and chymotrypsin, trypsin, amylase and lipase activities) were measured over a first experimental period of 4 days, during which the pigs continued to receive the balanced diet, and over a second experimental period of 8 days during which they were given a protein-free diet. The results show that the amount of pancreatic protein did not change during the period the protein-free diet was given. After 2 days, chymotrypsin specific activity dropped, while amylase and lipase specific activities decreased little and slowly after 6 days. However, for short-term experiments, the protein-free diet proved to be an adequate technique for determining the production of total endogenous nitrogen in the digestion tract.
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PMID:[Effect of a short-term protein-free diet on endogenous nitrogen secretion: exocrine pancreas secretion in the pig]. 648 7

The time-course of proteolysis of casein and gluten by pancreatic enzymes (trypsin, chymotrypsin, pancreatic juice) was studied in vitro with various concentrations of enzyme or substrate. The effect of a previous peptic proteolysis, with or without sodium phytate, on proteolysis by pancreatic juice was also studied. Proteolysis was evaluated by measuring the nitrogen in products solubilized in trichloroacetic acid (peptides + amino acids) and in phosphotungstic acid (amino acids). Without a previous peptic proteolysis, at a low enzyme/substrate ratio, the release of peptides and amino acids was greater for casein than for gluten. At a high enzyme/substrate ratio, peptide release by pancreatic juice and chymotrypsin was quite similar for casein and gluten but amino acid release was a little less for gluten. After a previous high peptic proteolysis without sodium phytate, pancreatic juice proteolysis, at a low enzyme/substrate ratio, was increased. Peptide release was similar for casein and gluten but amino acid release was a little less for the gluten. With sodium phytate, the release of peptides was quite similar for casein but was less for gluten. The release of amino acids was diminished in both cases. Thus, gluten was more resistant than casein to the action of pancreatic enzymes. Nevertheless, this was not necessarily observed when those enzymes were used for proteolysis at a high enzyme/substrate ratio or following a high peptic proteolysis. The differences between casein and gluten proteolyses have been discussed according to the specific action of the pancreatic enzymes. In conclusion, in comparing the proteolyses of various foods, it is important to use various enzyme/substrate ratios.
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PMID:[In vitro proteolysis of casein and gluten by pancreatic enzymes]. 681 34

In various studies during recent years, the use of p-aminobenzoic acid has been described in screening tests for exocrine pancreatic function. A synthetic three-unit compound N-benzoyl-L-tyrosyl-p-aminobenzoic acid has been administered orally and hydrolysed in the small intestine in the presence of chymotrypsin to N-benzoyl-L-tyrosine and p-aminobenzoic acid. This study describes a convenient procedure in which, after a selective extraction and derivatization with diazomethane, capillary gas chromatography is used combined with nitrogen-sensitive detection. With the proposed procedure, p-aminobenzoic acid and its major metabolites, acetyl-p-aminobenzoic acid and p-aminohippuric acid, can be monitored in serum and in urine samples.
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PMID:Simultaneous determination of p-aminobenzoic acid, acetyl-p-aminobenzoic acid and p-aminohippuric acid in serum and urine by capillary gas chromatography with use of a nitrogen-phosphorus detector. 697 21

Pancreatic secretion in rats was assessed by measuring the amounts of p-aminobenzoic acid (PABH) excreted in urine after oral administration of Ac-L-Tyr-PAB, and by determination of enzyme activity in pancreas and faeces. 3 groups of 7 rats were kept on diets with casein as the main source of nitrogen without (control K0) or with two levels of trypsin inhibitor (K1 and K2). Two other groups were fed diets with 40 and 80% of casein substituted by raw soya bean protein and having trypsin inhibitor contents equivalent to those in diets K1 and K2. Urinary excretion of PABH ranged from 99 to 105% of intake and were not different between control and experimental rats. The weight of pancreas and pancreatic activities of trypsin and chymotrypsin in all experimental rats were higher than in controls. The activity of chymotrypsin in the faeces of rats of groups K1 and K2 was greater than in K0 while in groups S1 and S2 it was about five times that in groups K1 and K2. Generally, it was greater on diets with more trypsin inhibitor. The activity of trypsin in the faeces of rats K0, K1 and S1 was several times less than in K2 and S2. It has been concluded that measurement of trypsin and chymotrypsin in faeces allows to estimate differences in the secretion of pancreatic enzymes.
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PMID:Use of Ac-L-Tyr-PAB for estimating the activity of chymotrypsin in rats. 698 85


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