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)

1. Pigs (twenty-one/diet) were weaned at 2 d of age and given liquid diets (200 g dry matter/l) at hourly intervals during a 26 d experiment. The pigs were fed on a scale based on live weight. The diets contained (g/kg DM): dried skim-milk 730 (diet A), dried whey 508.5, isolated soya-bean protein 218, DL-methionine 3.5 (diet S), and soya-bean oil 270 (diets A and S). Diet T contained equal proportions of diets A and S. Soya-bean supplied 0, 370 and 740 g crude protein (nitrogen x 6.25) kg total crude protein in diets A, T and S respectively. 2. Performance was similar for both diets A and T (P > 0.05). Pigs given diet S scoured severely, and fourteen died. The survivors grew very poorly. Nitrogen retention (g/d per kg live weight) was greater for diet A compared with diet T (P < 0.01), and decreased with age (P < 0.001). 3. Protein digestion was examined in the pigs killed at 28 d of age. The amount of soya-bean protein in the diet did not affect the amount of digesta in the stomach, but soya-bean protein decreased the pH, DM and total N content of the digesta (P < 0.01), and increased, though not significantly (P > 0.05), pepsin activity in the digesta and stomach tissue. Acid secretion into the stomach appeared to be enhanced in pigs given a diet containing soya-bean protein. 4. Amounts of trypsin, chymotrypsin, total N and proportion of non-protein-N in the digesta from the small intestine were similar for both diets A and T. The amounts for both diets were greater in the distal compared with the proximal region of the small intestine (P < 0.05). Chymotrypsin activity in the pancreas was reduced (P < 0.05) in pigs given diet T, although this reduction did not seem to impair digestion in 28-d-old pigs. Trypsin activity in the pancreas was similar for both diets A and T. 5. It seems likely that the neonatal pig does not have the digestive capacity to tolerate the large daily intakes of soya-bean protein when dried skim-milk was totally replaced in the diet (diet S). When half the dried skim-milk was replaced, protein digestion was not impaired in 28-d-old pigs.
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PMID:Artificial rearing of pigs. 11. Effect of replacement of dried skim-milk by an isolated soya-bean protein on the performance of the pigs and digestion of protein. 719 26

1. Four pelleted diets were prepared containing milk or isolated soya-bean protein (ISP) as the major protein source. The milk and ISP were given either as intact proteins or partially (0.650 hydrolyzed with papain before feeding. 2. The diets were given ad lib. to thirty-two pigs from 7-28 d of age. The pigs were slaughtered at 28 d of age. 3. Weight gains, food conversion ratios and nitrogen balances of pigs given diets containing milk protein were better than those of diets containing ISP (231 g/d, 0.80 and 11.5 g/d compared to 209 g/d, 0.88 and 9.00 g/d respectively). 4. Partial hydrolysis of proteins before feeding did not affect the performance of the pigs. 5. Apparent digestibilities of N before the ileum and in the whole tract were 0.78 and 0.94 for the pigs given the ISP diets and 0.86 and 0.97 for the pigs given the milk-protein diets. 6. Retention time of ISP diets in the whole digestive tract was 1475 min and that of the milk-protein diets was 1089 min. 7. pH of digesta in the stomach was 5.0-5.3 for all diets and increased to 6.9-7.1 in the ileum. 8. There were no differences in flows of total N and protein N to the ileum and lower digestive tract between the pigs given the intact-and hydrolyzed-protein diets. 9. Apparent absorptions of N in the stomach, duodenum and jejenum were greater in the pigs given diets containing hydrolyzed proteins than in those given diets containing the intact proteins. 10. Flows of total N and protein N to the ileum tract were greater when the pigs were given the ISP diets than when they were given the milk-protein diets. 11. Hydrolysis of proteins before feeding resulted in a reduced trypsin and chymotrypsin activity in the duodenum and pancreas. 12. Retention of dietary N in the carcass was greater in pigs given the milk-protein diets (0.79) than in those given the ISP diets (0.68).
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PMID:Digestion in the pig between 7 and 35 d of age. 6. The digestion of hydrolyzed milk and soya-bean proteins. 719 57

1. Pigs (sixteen/diet) were weaned at 2 d of age and given liquid diets (200 g dry matter/l) during a 26 d experiment. The pigs were fed on a scale based on live weight. Dried skim-milk was the only source of protein in diet U and was partially or totally replaced by a soya-bean isolate (diet B) or a concentrate (diets C and D). Soya-bean protein provided 500, 700 or 350 g/kg total crude protein (nitrogen x 6.25) in diets B, C and D respectively. 2. Performance was similar for diets B and D, but poorer than that of pigs given diet U. The apparent digestibility and retention of N of these diets was similar. Pigs given diet C scoured severely and twelve died. 3. Protein digestion was studied in pigs given diets U, B and D, killed at 28 d of age, at the termination of the feeding experiment. The dry matter content and proportion of N in the digesta in the stomach were reduced in pigs given soya-bean protein. Pepsin concentrations in digesta and stomach tissue were unchanged. 4. The concentrations of trypsin and chymotrypsin in the pancreas were greater in pigs given the soya-bean protein concentrate compared with milk protein, but only the increase in trypsin was significant (P less than 0.01). Digesta from the small intestine of pigs given the soya-bean-protein isolate contained less chymotrypsin (P less than 0.05). There were no differences in the proportion of non-protein-N in the total N in the digesta, suggesting that proteolysis of the milk and soya-bean proteins were equally by 28 d of age.
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PMID:Artificial rearing of pigs. 12. Effect of replacement of dried skim-milk by either a soya-protein isolate or concentrate on the performance of the pigs and digestion of protein. 720 50

Substitution of casein by proteins of milk serum or by bovine blood serum albumin in the diet of 15 days old rats, maintained on artificial food, led to a 2-3-fold increase in the rate of transport of alimentary protein from stomach and to a corresponding elevation in content of nitrogen containing material in chymus of the small intestine. Distinct activation of trypsin and chymotrypsin as well as an increase in concentration of low molecular products of the protein proteolysis were found in the chymus of small intestine.
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PMID:[Digestion of incoagulable proteins during the early postnatal period of development]. 745 63

Higher nitrogen and lipid digestibilities have been obtained with diets containing cottonseed flour rather than soybean flour. To explain these results, in vitro studies were carried out to compare the effects of raw and heated glandless (without gossypol) cottonseed flours versus soybean flours on pancreatic digestive enzyme activities. These effects were compared with those obtained without addition of flour in standard assays. Apparent lipase (lipase colipase dependent) and potential lipase (lipase with saturating amounts of colipase), colipase, phospholipase A2, amylase, trypsin and chymotrypsin activities were measured on specific substrates. Phospholipase A2 and amylase activities were enhanced, while chymotrypsin activity was diminished with both raw and heated flours. Compared with raw and heated soybean flours, raw and heated cottonseed flours promoted higher potential lipase, chymotrypsin, trypsin and lipase activities. Heat treatment of cottonseed flour enhanced apparent lipase, colipase, chymotrypsin, trypsin activities and diminished potential lipase, phospholipase A2 and amylase activities. When soybean flour was heated, apparent lipase, phospholipase A2, chymotrypsin, trypsin and amylase activities were raised while those of potential lipase were decreased. Our findings show that in vitro raw or heated cottonseed flours affect less digestive enzymes than raw or heated soybean flours, apparent lipase activity excepted. Moreover, only chymotrypsin activities were seriously lowered with both flours, especially with raw soybean flour. Hypotheses are suggested to account for the differences in alterations.
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PMID:In vitro rat pancreatic digestive enzyme activities and raw and heated glandless cottonseed and soybean flours. 753 15

Day-old male meat-type chicks were fed a commercial starter diet supplemented with 2 levels of enzyme preparations containing amylase and proteases up to 14 d of age. Enzyme supplementation had no significant effect on feed intake or growth rate, and was accompanied by a significant decrease in gizzard content and small intestine weight. The intestine contents increased and this increase was accompanied by a significant decrease in its pH. Enzyme supplementation depressed the activity of chymotrypsin in the pancreas and the activity of amylase, trypsin and chymotrypsin in the intestinal contents. Some carry-over effects were observed on d 42, 4 weeks after the cessation of the enzyme supplements. These were mainly a significant depression in the activity of trypsin in the intestinal contents. In a balance study, diets supplemented with 0,250 and 1,000 micrograms/kg enzyme preparations were supplied. Exogenous enzyme supplements had no significant effect on the digestibility of all the nutrients studied except for the highest level of enzyme supplementation, which improved slightly but consistently the digestibility of amino acids. Some age effects were observed, mainly a decrease in the digestibility of fat and starch, and in the ME of the diet from weeks 1 to 2 followed by an increase during week 3. Protein digestibility and retention of nitrogen decreased with age.
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PMID:Effect of age and exogenous amylase and protease on development of the digestive tract, pancreatic enzyme activities and digestibility of nutrients in young meat-type chicks. 753 5

Four barrows, initial wt. 70 kg, fitted with permanent pancreatic cannulas according to the "Pouch Method", were used to investigate the effect of dietary inclusion of pectin on pancreatic secretions. The pigs were fed two corn starch-based diets, containing 16% crude protein from soybean meal, with 0 or 7.5% pectin. The pigs were fed twice daily, at 08:30 and 20:30, 900 g each meal. Pancreatic juice was collected continuously at 1-h intervals for a total of 24 h. The inclusion of pectin did not affect (p > .05) the flow of pancreatic juice and the total secretion of nitrogen, lipase, trypsin and chymotrypsin. However, there was a significant (p < .05) decrease in the secretion of alpha-amylase, which was actually a direct result of the replacement of starch by pectin.
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PMID:Exocrine pancreatic secretions in pigs as influenced by the source of carbohydrate in the diet. 769 Oct 18

The effect of dietary pectin on apparent ileal and fecal digestibilities of protein and amino acids and on pancreatic secretions was studied in two experiments with growing pigs (initial weight 70 kg). Four barrows were fitted with simple T-cannulas for collection of ileal digesta; another four barrows were fitted with permanent re-entrant cannulas for collection, sampling and subsequent return of pancreatic juice. Dietary pectin included at a level of 7.5 g/100 g in a cornstarch-based diet significantly depressed apparent ileal and fecal protein and amino acid digestibilities. This depression in the small intestine could be attributed to both an increase in endogenous protein secretions and a decrease in the efficiency of digestion. In the large intestine, pectin was used by intestinal microbes as the principal energy source to catabolize nitrogenous compounds and to stimulate bacterial nitrogen assimilation, thus altering the amino acid profile of protein voided in feces. The inclusion of pectin did not affect the flow of pancreatic juice or the total secretion of protein, lipase, trypsin and chymotrypsin. However, there was a significantly lower secretion of alpha-amylase, which was a direct result of the replacement of starch by pectin. The results demonstrate that pectin may have a detrimental effect on the processes of protein digestion and absorption but does not affect the secretion of pancreatic proteolytic enzymes in pigs.
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PMID:Dietary pectin's effect on ileal and fecal amino acid digestibility and exocrine pancreatic secretions in growing pigs. 791 17

The reaction of enantiomerically pure (2S)-N-acetyl-L-alanyl-L-phenylalanyl alpha-chloroethane with gamma-chymotrypsin was studied as a probe of the mechanism of inactivation of serine proteases by peptidyl chloroalkanes. It was determined crystallographically that the peptidyl chloroethane alkylates His57 with retention of configuration at the chiral center, indicating a double displacement mechanism. We think it likely that a Ser195-epoxy ether adduct is an intermediate on the inactivation pathway, although other possibilities have not been disproven. Kinetic data reported by others [Angliker et al. (1988) Biochem. J. 256, 481-486] indicate that the epoxy ether intermediate is not an irreversibly inactivated form of enzyme [a conclusion confirmed experimentally (Prorok et al. (1994) Biochemistry 33, 9784-9790)] and that both ring closure of the tetrahedral intermediate to form the epoxy ether and ring opening by His57 partially limit the first-order rate constant for inactivation, ki. The peptidyl chloroethyl derivative adopts a very different active site conformation from that assumed by serine proteases inactivated by peptidyl chloromethanes. Positioning the chloroethyl derivative into the conformation adopted by chloromethyl derivatives would cause the extra methyl group to make a bad van der Waals contact with the inactivator P2 carbonyl carbon, thereby preventing the formation of the invariant hydrogen bond between the inactivator P1 amide nitrogen and the carbonyl group of Ser214. We conclude that the unusual conformation displayed by the chloroethyl derivative is caused by steric hindrance between the extra methyl group and the rest of the inactivator chain.
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PMID:Three-dimensional structure of chymotrypsin inactivated with (2S)-N-acetyl-L-alanyl-L-phenylalanyl alpha-chloroethane: implications for the mechanism of inactivation of serine proteases by chloroketones. 794 90

The nematophagous fungus Verticillium chlamydosporium secreted several proteases in submerged culture in which soya peptone was the sole carbon and nitrogen source. One protease, VCP1 (M(r) 33,000, pI 10.2), was purified 14-fold from culture filtrates to apparent homogeneity using preparative isoelectric focusing in free solution, and shown to rapidly hydrolyse the chymotrypsin substrate Suc-(Ala)2-Pro-Phe-pNA and elastin. VCP1 had a Km for Suc-(Ala)2-Pro-Phe-pNA of 4.3 x 10(-5) M and a kcat of 5.8 s-1. It was highly sensitive to PMSF and TPCK, but only moderately sensitive to chicken egg-white and soya bean trypsin inhibitors. VCP1 degraded a wide range of polymeric substrates, including Azocoll, hide protein, elastin, casein and albumin, and accounted for most of the non-specific protease activity detected in culture filtrates. The purified enzyme hydrolysed proteins in situ from the outer layer of the egg shell of the host nematode Meloidogyne incognita and exposed its chitin layer. VCP1 was secreted by several isolates of V. chlamydosporium and V. lecanii, pathogens of nematodes and insects respectively, but not plant-pathogenic species of Verticillium. These observations suggest that VCP1 or similar enzyme(s) may play a role in the infection of invertebrates.
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PMID:The nematophagous fungus Verticillium chlamydosporium produces a chymoelastase-like protease which hydrolyses host nematode proteins in situ. 800 May 41


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