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)

In order to clarify the function of the carbohydrate moiety of bovine kappa-casein, kappa-casein components having different carbohydrate contents were prepared by DEAE-cellulose chromatography. Five adsorbed fractions so obtained had an identical peptide chain and contained carbohydrate moieties of increasing size in the order of components P-2, P-3, P-4, P-5 and P-6. The subsceptibility of kappa-casein components, having different carbohydrate contents, to various proteases was examined. kappa-Casein components were subjected to calf rennin [chymosin; EC 3.4.23.4], bovine trypsin [EC 3.4.21.4], alpha-chymotrypsin [EC 3.4.21.1], pronase [EC 3.4.24.4] and human plasmin [EC 3.4.21.7]. The component containing a larger carbohydrate moiety was less susceptible to hydrolysis than the component containing a smaller carbohydrate moiety. Rennin, trypsin, alpha-chymotrypsin and pronase hydrolyzed each component with a different reaction rate. On the contrary, human plasmin hydrolyzed component P-2, but did not hydrolyze component P-5. These results indicate that the carbohydrate moiety of kappa-casein components to various proteases.
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PMID:Susceptibility of kappa-casein components to various proteases. 15 50

1. The reactivities of phenylglyoxal (PGO), glyoxal (GO), and/or methylglyoxal (MGO) with several proteins, including ribonuclease A [EC 3.1.4.22] and its derivatives, alpha-chymotrypsin [EC 3.4.21.1], trypsin [EC 3.4.21.4], lysozyme [EC 3.2.1.17], pepsin [EC 3.4.23.1], rennin [EC 3.4.23.4], thermolysin, and insulin and its B chain, have been examined. From analyses of the reaction products, PGO was shown to be the most specific for arginine residues. GO and MGO also reacted rapidly with arginine residues, but they also reacted with lysine residues to a significant extent. A side reaction with N-terminal alpha-amino groups was observed with each of these reagents. 2. Two arginine residues out of four in ribonuclease A, two out of three in alpha-chymotrypsin, one out of two in trypsin, one out of two in pepsin, and one out of five in rennin appeared to react with PGO fairly rapidly, indicating a difference in the relative accessibility of these residues by the reagent. Extensive modification of the arginine residues by PGO occurred with RCM-derivatives of ribonuclease A and insulin B chain. The N-terminal isoleucine residues of alpha-chymotrypsin and trypsin appeared to be unreactive with PGO because of salt bridge formation with an aspartyl residue. The activity of alpha-chymotrypsin toward N-benzoyl-L-tyrosine ethyl ester and the lytic activity of lysozyme were lost rapidly on treatment with PGO, as in the case of ribonuclease A. Pepsin and rennin were only partially inactivated by reaction with PGO.
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PMID:Further studies on the reactions of phenylglyoxal and related reagents with proteins. 32 41

We have studied the effect of such milk proteins as caseins, lactalbumin, and lactoglobulin, on proliferation and immunoglobulin production of human-human hybridoma HB4C5 cells. It was found that alpha-, beta-, and kappa-caseins stimulated both proliferation and IgM product ion of human-human hybridoma HB4C5 cells, while the activities of alpha-lactalbumin and beta-lactoglobulin were negligible. To localize the active sites of these caseins, effect of protease treatments on the activities were examined. When caseins were digested with trypsin, casein digests stimulated proliferation of the hybridoma, but not their IgM production. When kappa-casein was digested with chymosin and fractionated to p-kappa-casein and glycomacropeptide, both fragments stimulated proliferation of the cells, but only p-kappa-casein fragment stimulated IgM production. These results indicate that kappa-casein has at least two proliferation stimulating sites and an IgM production stimulating site in the p-kappa-casein region.
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PMID:Stimulation of proliferation and immunoglobulin production of human-human hybridoma by various types of caseins and their protease digests. 136 81

Changes in the activities of three gastric and nine pancreatic enzymes plus colipase were determined during postnatal development and weaning in calves. In calves exclusively milk-fed for 2, 7, 28, 56, 70 and 119 d, the enzyme activities per kilogram of empty live weight increased with age for chymotrypsin, elastase, carboxypeptidases A and B, ribonuclease and alpha-amylase, decreased for chymosin, lysozyme and colipase but showed no change in the case of pepsin, trypsin, lipase and phospholipase A2 compared with animals at birth. The greatest increase was that in alpha-amylase activity (about 50-fold between d 2 and 119). In calves weaned between d 28 and 56, all the activities were higher than in milk-fed animals, except that of chymosin (which was slightly lower) and that of colipase (which did not change). At 119 d of age, chymotrypsin, carboxypeptidase A, alpha-amylase and lipase were 1.6- to fourfold higher in ruminants than in preruminants. Thus, most enzyme activities were modified first by colostrum and milk intake, and again upon weaning by development of the forestomachs and ingestion of solid food. These ontogenic patterns might be under the control of many gut regulatory peptides, the plasma concentrations of which changed simultaneously. Some gastric and pancreatic enzymes were correlated to plasma concentrations of these gut regulatory peptides.
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PMID:Gastric and pancreatic enzyme activities and their relationship with some gut regulatory peptides during postnatal development and weaning in calves. 137 46

Proteolytic activities of chymosin, bovine pepsin, Mucor miehei rennet, Cryphonectria parasitica (formerly Endothia parasitica) rennet, trypsin, and chymotrypsin on kappa-casein macropeptide were measured. Macropeptide solutions (10 mg/ml of .05 M, pH 6.6 phosphate buffer) were incubated with the enzymes at 37 degrees C for various times, and their reactions were stopped by adding .025 ml of pepstatin (1 mg/ml of methanol). Peptides released from kappa-casein macropeptide were then fractionated using reverse-phase HPLC. At the pH of milk (pH 6.6), kappa-casein macropeptide was resistant to enzymic action by chymosin, bovine pepsin, and M. miehei and C. parasitica rennets. Bovine pepsin hydrolyzed kappa-casein macropeptide at pH 3. kappa-Casein macropeptide was readily hydrolyzed at pH 6.6 by trypsin and chymotrypsin. Possible physiological functions of the kappa-casein macropeptide are discussed in light of these findings.
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PMID:Proteolytic activity of proteinases on macropeptide isolated from kappa-casein. 150 May 45

Thirty-nine male Friesian calves, divided into three groups (L, S and SL), were reared until they were 147 to 175 days old. Group L calves remained preruminant until slaughter. Group S calves were weaned between 5 and 9 weeks of age and then received a concentrate feed and dehydrated fescue ad libitum. Besides this diet, group SL calves received a liquid supplement containing whey powder and soyabean oil meal, supplying a total of 940 g of dry matter and 5,060 g of water per day. The slaughter age of the calves in each group was chosen so that carcass weight in the three groups was similar. At slaughter, the abomasum and pancreas of each animal were collected and the gastric (chymosin and pepsin) and pancreatic (chymotrypsin, trypsin, lipase and amylase) enzymes were assayed. Weaning caused a decrease in the chymosin content and an increase in the pepsin content of the abomasum. The amount of chymosin per kg of carcass was on the average 2.8-fold lower and that of pepsin 1.9-fold higher in groups S and SL than in group L. The amount of pepsin tended to be higher in group S than in group SL, but only the difference observed (36%) for the total amount was significant. In group S, the pancreata showed more chymotrypsin, trypsin and amylase activities but less lipase activity than in group L; the observed differences in these activities per kg of carcass were 32, 49, 70 and 24%, respectively. The activities of group SL were lower than those of group L for trypsin, chymotrypsin and lipase but higher for amylase (17, 12, 44 and 18%, respectively). Group SL exhibited lower activities than group S (55, 67, 16 and 44%, respectively, for trypsin, chymotrypsin, lipase and amylase). Weaning appeared to induce large changes in abomasal and pancreatic enzyme potentialities which exhibited patterns similar to the variations in the amounts of substrate intake. In our experimental conditions, giving a liquid supplement to ruminant calves had a depressive effect on the activities of the enzymes (except chymosin), in the pancreas and the abomasum.
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PMID:Enzyme potentialities of the abomasum and pancreas of the calf. II. Effects of weaning and feeding a liquid supplement to ruminant animals. 241 Sep 61

The effect of age and weaning on enzyme activities of abomasum and pancreas of the lamb was studied. Sixty-nine lambs were either maintained at the preruminant stage until 42 days of age or weaned between 20 and 30 days. They were slaughtered between birth and 100 days, and the mucosa of their abomasum and their pancreas were collected. At 2 days of age there was a threshold of glandular growth and of development of enzyme secretory potentialities. Pancreas showed an extensive hyperplasia without growth until day 2; its weight increased after day 7 but only by hypertrophy. Quantities of gastric enzymes in relation to empty live weight increased between birth and 2 days, but that of chymosin then decreased, whereas pepsin did not change significantly; effects of weaning were similar. The evolution of pancreatic enzyme activity was usually the reverse of that of chymosin; however, trypsin activity was low at birth and that of colipase did not increase at weaning. The ratio of colipase to lipase was always higher than 1, showing that lipase always was saturated in the lamb. The pancreas seemed to take over the secretion of abomasal proteolytic enzymes. Potentialities of enzyme digestion appeared to be influenced mainly by the age or weight of the animal; these potentialities were minimal for at least several days during the first neonatal week and, if there was enzymatic adaptation to the amounts of the ingested substrate, it did not occur rapidly.
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PMID:Effects of age and weaning on enzyme activities of abomasum and pancreas of the lamb. 619 30

The effect of age on the enzyme potentialities of abomasum (chymosin and pepsin) and pancreas (chymotrypsin, trypsin, colipase and amylase) was studied in the preruminant calf. Three foetuses were collected after slaughter of their dams (260 d of gestation) and 32 calves were maintained as preruminant and slaughtered between birth and 147 d of age. The abomasal mucosa and pancreata were collected and analysed. The abomasal and pancreatic glands of the foetus contained large amounts of enzymes, except pepsin and amylase. On a liveweight basis, the amount of chymosin was maximal at 1.5 d post partum and decreased thereafter; the amount of pepsin increased until 21 d and then did not change. The development of pancreatic enzyme activities was usually the reverse of that of chymosin; amylase activity was particularly low at birth. After birth, the development of secretory potentialities could be divided into three phases: during the colostral period, the trend of pancreatic activities was the reverse of that observed for abomasal activities; from 1.5 to 21 d, most of the enzyme potentialities (except those of chymosin and amylase) appeared to be stimulated by intake level; after 21 d (1.5 d for chymosin and amylase), the development of secretory potentialities appeared to depend more on age than on intake.
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PMID:Enzyme potentialities of the abomasum and pancreas of the calf. I.--Effect of age in the preruminant. 620 51

To determine the structural basis for the highly specific action of renin, structural features of the active site and the complete amino acid sequence of mouse submaxillary gland renin were determined. A rapid method was developed for a large scale purification of renin from mouse submaxillary gland. The active site of renin was shown to consist of 2 aspartyl residues, 2 tyrosyl residues and one arginyl residue, the structures analogous to the active site of pepsin and other acid proteases. Renin was found to consist of one heavy chain (Mr = 31,036) and one light chain (Mr = 5,458) connected by a disulfide bridge. Amino acid sequences of these chains were determined using overlapping peptides generated by cleavage with cyanogen bromide, trypsin, Staphylococcus aureus protease and Lysobacter enzymogenes endoproteinase Lys-C. Sequences involving 2 catalytically essential aspartyl residues 32 and 215, characteristic to acid proteases, were found identical with pepsin, penicillopepsin and chymosin. The sequence of L-chain was homologous with carboxyl terminal region of porcine pepsin in 46% of amino acid residues. H-chain showed 41% homology with 284 residues on the amino-terminal side of the porcine pepsin molecule. Residues identical in renin and acid proteases are distributed throughout the length of the molecules, suggesting a similarity in their overall structure.
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PMID:Structure of mouse submaxillary gland renin. 635 66

Thirty suckling pigs of 4 litters were divided into an experimental and a control group. The experimental piglets were treated perorally from 14 to 20 days of age with rising doses of triiodothyronine, which were combined with prednisolone for the last 3 days. On the day following the conclusion of the treatment (at 3 weeks of age) the piglets were killed by bleeding for the determination of digestive enzymes. The experimental piglets showed a significant increase of intestinal trypsin (p less than 0.01) and pancreatic amylase (P less than 0.05) activities over the control; a significant decrease of gastric chymosin activity (P less than 0.05) was caused by the great inter-group differences within one litter. Ten of the 11 parameters tested indicated precocious maturation of the digestive enzymes of the experimental piglets, however, most of these differences were not significant. Further studies are required for the possible utilization of this finding in the early weaning practice.
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PMID:The effect of triiodothyronine-prednisolone treatment on the development of digestive enzymes in the suckling pig. 710 37


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