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)

The effect of ingesting isocaloric and isonitrogenous diets with increasing amounts of lipid (0-30%) and consequently decreasing amounts of carbohydrates (68.7-1.25%) on the exocrine pancreas was studied in adult male Wistar rats. Pancreatic contents of chymotrypsin, lipase and colipase activity, as well as synthesis of amylase, lipase, procarboxypeptidases and individual serine proteases were examined. Lipid-free diets and diets containing 1% lipid were found to have little effect on pancreatic proteins as compared with lipid-rich diets where two distinct patterns of response were observed. Ingestion of diets containing 3-20% lipid resulted in a progressive increase in the activity of lipase, colipase and chymotrypsin up to 2-fold in the first case and 1.6-fold in the two other cases when animals were fed the 20% fat diet. Under the latter conditions, the relative synthesis of secretory proteins, as expressed as percentage of the radioactivity incorporated into individual proteins compared to that incorporated into the total mixture of exocrine proteins, was unchanged for procarboxypeptidases, whereas it was stimulated for lipase (2-fold) and serine proteases (1.6-fold). Amylase relative synthesis progressively decreased as the lipid content of diets increased. Consumption of hyperlipidic diets containing 25% and 30% fat resulted in a further enhancement in the activity of lipase and colipase in the gland in contrast with chymotrypsin activity which was unchanged as compared to the control diet (3% lipid). As far as biosynthesis was concerned, a plateau in the relative synthesis of lipase and serine protease was reached. Amylase relative synthesis further decreased down to 2.2-fold when rats were fed the 30% fat-rich diet whereas that of procarboxypeptidases was markedly increased (about 1.7-fold). Absolute rates of synthesis of total pancreatic secretory proteins, as expressed with regard to the DNA content of the tissue, indicated that biosynthesis of all secretory pancreatic proteins was stimulated by hyperlipidic diets (at least 2-fold with the 30% lipid diet). Consequently, when such an increase was taken into consideration, the absolute synthesis of amylase was found to be unchanged throughout the dietary manipulations, whereas that of lipase, procarboxypeptidases and serine proteases were stimulated by 4.0-fold, 3.4-fold and 3.2-fold, respectively.
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PMID:Effects of inverse changes in dietary lipid and carbohydrate on the synthesis of some pancreatic secretory proteins. 381 84

Regulation by food content of the expression of genes encoding pancreatic proteases was studied in rats fed diets containing 15%, 25% or 70% protein (w/w) (diet I, II and III). Trypsin, chymotrypsin and elastase activities in pancreas were 1.4, 2.8 and 2 times higher in diet III than in diet I whereas carboxypeptidase A level was unchanged. As compared to diet I, the pancreatic concentration of mRNAs encoding trypsinogen I and chymotrypsinogen B, measured by filter hybridization to specific cDNA probes, were found respectively 3.6 and 3.9 times higher in diet III, and 1.9 and 2.6 times higher in diet II. Elastase I mRNA concentration was 1.8 times higher in diet III, but unchanged in diet II. Procarboxypeptidase A mRNA concentration was not affected. It is concluded to a coordinate pre-translational regulation of serine protease genes expression by the protein content of diet, differing however in amplitude and sensitivity among the three species of enzymes studied.
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PMID:Regulation of proteolytic enzyme activities and mRNA concentrations in rat pancreas by food content. 388 43

Two of the major enzymes present in and released from rat mast cells are chymotrypsin-type serine protease (chymase) and trypsin-type serine protease (tryptase), and these have been postulated to be important in the inflammatory reactions. There have been no clear data regarding the trypsin-type protease in rat mast cells. Tryptase was recently purified from rat peritoneal mast cells with an associated protein (trypstatin) that inhibited the protease activity above pH 7.5. Chymase was also purified from rat peritoneal cells by employing a one-step method involving hydrophobic chromatography on octyl-Sepharose 4B or arginine-Sepharose 4B. The properties of chymase and tryptase were described in relation to substrate specificity and their relative sensitivity to inhibitors. It was found that proteolytic activities of these enzymes were modulated by naturally occurring substances, such as phosphoglycerides, long-chain fatty acids, and trypstatin. There is as yet little evidence for the physiological roles of these enzymes in the inflammatory reaction. It has been found that the specific, low-molecular-weight inhibitor of chymase, chymostatin, and that of tryptase, leupeptin, inhibit histamine release induced by addition of anti-rat IgE to mast cells. However, the inhibitors with molecular weights of more than 6000 were found to have no effect in this process. The data suggest that chymase and tryptase in mast cell granules play a crucial or significant role in the process of degranulation.
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PMID:Chymotrypsin- and trypsin-type serine proteases in rat mast cells: properties and functions. 389 Jul 54

The structure of alpha-lytic protease, a serine protease produced by the bacterium Lysobacter enzymogenes, has been refined at 1.7 A resolution. The conventional R-factor is 0.131 for the 14,996 reflections between 8 and 1.7 A resolution with I greater than or equal to 2 sigma (I). The model consists of 1391 protein atoms, two sulfate ions and 156 water molecules. The overall root-meansquare error is estimated to be about 0.14 A. The refined structure was compared with homologous enzymes alpha-chymotrypsin and Streptomyces griseus protease A and B. A new sequence numbering was derived based on the alignment of these structures. The comparison showed that the greatest structural homology is around the active site residues Asp102, His57 and Ser195, and that basic folding pathways are maintained despite chemical changes in the hydrophobic cores. The hydrogen bonds in the structure were tabulated and the distances and angles of interaction are similar to those found in small molecules. The analysis also revealed the presence of close intraresidue interactions. There are only a few direct intermolecular hydrogen bonds. Most intermolecular interactions involve bridging solvent molecules. The structural importance of hydrogen bonds involving the side-chain of Asx residues is discussed. All the negatively charged groups have a counterion nearby, while the excess positively charged groups are exposed to the solvent. One of the sulfate ions is located near the active site, whereas the other is close to the N terminus. Of the 156 water molecules, only seven are not involved in a hydrogen bond. Six of these have polar groups nearby, while the remaining one is in very weak density. There are nine internal water molecules, consisting of two monomers, two dimers and one trimer. No significant second shell of solvent is observed.
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PMID:Refined structure of alpha-lytic protease at 1.7 A resolution. Analysis of hydrogen bonding and solvent structure. 390 Apr 16

We previously have isolated cDNA clones for several mRNAs that increase in abundance during the differentiation of 3T3 adipocytes but whose physiological role is unknown. We show here that a mRNA that is complementary to one of these clones and encodes a protein of 28 kDa is expressed abundantly in mouse fat pads but not in several other mouse tissues. Sequence analysis of the corresponding cDNA clone indicated that the encoded protein shows 30% overall amino acid homology to several serine proteases including trypsin, chymotrypsin, and elastase. Homology is much higher (64%) between the 28-kDa protein and regions that are strongly conserved among the members of the serine protease family. The derived protein also has key features characteristic of active serine proteases, including the histidine, aspartic acid, and serine residues, which comprise the charge relay system, and a potential cleavage site for activation of the zymogen. Primer extension analysis performed to obtain the sequence of the 5' end of mRNA that encodes the 28-kDa protein indicates that two forms of this mRNA exist and probably arise through alternative splicing. The two mRNAs encode signal sequences that differ by the deletion of one amino acid near the predicted cleavage site of the signal peptide. These results demonstrate that adipocyte differentiation is accompanied by the expression of mRNA encoding a serine protease homologue that can be synthesized with two different signal peptides.
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PMID:A developmentally regulated mRNA from 3T3 adipocytes encodes a novel serine protease homologue. 390 Oct 3

A serine protease from sea urchin eggs has been isolated by affinity chromatography on soybean trypsin inhibitor-agarose. Benzamidine hydrochloride was included to minimize autodegradation. We present data on the properties of the protease with respect to molecular weight and its interaction with trypsin inhibitors and substrates. The molecular weight of the enzyme is 47 000 by gel filtration under nonreducing conditions and 35 000 by electrophoresis in the presence of sodium dodecyl sulfate and dithiothreitol. The pH optimum and Km with N alpha-benzoyl-L-arginine ethyl ester (BAEE) are 8.0 and 75 microM, respectively. The specific activity is comparable to that of bovine pancreatic trypsin. Proteolytic activity was measured by beta-casein hydrolysis. The caseinolytic activity is completely inhibited by 1 mumol of soybean trypsin inhibitor (SBTI) per micromole of enzyme. BAEE esterase activity is inhibited competitively by SBTI (Ki = 1.6 nM), lima bean trypsin inhibitor (150 nM), chicken ovomucoid (100 nM), and leupeptin (130 nM). Bowman-Birk inhibitor, benzamidine hydrochloride, and antipain are also inhibitors of the purified enzyme. Inhibition by phenylmethanesulfonyl fluoride and N alpha-p-tosyl-L-lysine chloromethyl ketone indicates the presence of serine and histidine residues in the active center, respectively. The chymotrypsin inhibitor L-1-(tosylamido)-2-phenylethyl chloromethyl ketone is ineffective. The protease is susceptible to autodegradation which can result in the appearance of a minor 23-kilodalton component. The egg protease appears to be similar in many respects to trypsins and trypsin-like enzymes isolated from a wide variety of sources, including sea urchin and mammalian sperm.
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PMID:Characterization of soybean trypsin inhibitor sensitive protease from unfertilized sea urchin eggs. 390 77

A 33-kD glycoprotein, known as the "prostate-specific antigen," was purified to homogeneity from human seminal plasma. The prostatic protein was identified as a serine protease, and its NH2-terminal sequence strongly suggests that it belongs to the family of glandular kallikreins. The structural protein of human seminal coagulum, the predominant protein in seminal vesicle secretion, was rapidly cleaved by the prostatic enzyme, which suggests that this seminal vesicle protein may serve as the physiological substrate for the protease. The prostatic enzyme hydrolyzed arginine- and lysine-containing substrates with a distinct preference for the former. All synthetic substrates tested were poor substrates for the enzyme. Synthetic Factor XIa substrate (pyro-glutamyl-prolyl-arginine-p-nitroanilide), and the synthetic kallikrein substrate (H-D-prolyl-phenylalanyl-arginine-p-nitroanilide) were hydrolyzed with maximum specific activities at 23 degrees C of 79 and 34 nmol/min per mg and Km values of 1.0 and 0.45 mM, respectively. Synthetic substrates for plasmin, chymotrypsin, and elastase were either not hydrolyzed by the enzyme at all, or only hydrolyzed very slowly.
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PMID:A kallikrein-like serine protease in prostatic fluid cleaves the predominant seminal vesicle protein. 390 93

Proton NMR spectra of serine proteases in 1H2O solutions typically show a single resonance at very low magnetic field--i.e., 14-18 ppm from dimethylsilylapentanesulfonate. This resonance has been assigned to the proton hydrogen bonded between aspartic acid-102 and histidine-57 (chymotrypsin numbering system) of the "charge-relay system" or catalytic triad of serine proteases [Robillard, G. & Shulman, R. G. (1972) J. Mol. Biol. 71, 507-511]. Since then, there have been a number of reports that have cast doubt on its correctness. In the present work we have tested this assignment using alpha-lytic protease (EC 3.4.21.12, Myxobacter alpha-lytic proteinase), a bacterial serine protease homologous to elastase, which is specifically labeled with nitrogen-15 at N delta 1 of its single histidine residue. The low-field region of the proton spectra of this labeled enzyme shows a single resonance having the properties reported [Robillard, G. & Shulman, R. G. (1974) J. Mol. Biol. 86, 519-540], which, in addition, exhibits spin-spin splitting to the nitrogen-15 label. The observation of this 15N delta 1-H coupling makes the assignment of this resonance to the charge-relay proton unequivocal.
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PMID:Confirmation of the assignment of the low-field proton resonance of serine proteases by using specifically nitrogen-15 labeled enzyme. 393 65

Phenoloxidase activation in the whole hemolymph of Sarcophaga bullata and Manduca sexta larvae is shown to be achieved by proteolytic cleavage of the proenzyme. This process is inhibited by the serine protease inactivator, Diisopropyl phosphofluoridate. Endogenous protease inhibitors isolated from the larvae inhibit alpha-chymotrypsin mediated prophenoloxidase activation in the hemolymph. These observations suggest that the endogenous protease inhibitors prevent undesired activation of prophenol oxidase in the hemolymph by inhibiting the serine protease involved in the activation process.
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PMID:Endogenous protease inhibitors prevent undesired activation of prophenolase in insect hemolymph. 393 7

We have reported that a serine protease from Pronase, homologous with bovine chymotrypsin, is both active and stable in 6 M guanidinium chloride. The present investigation examined the possibility that this unique property might be used to permit the enzyme to engage in its own purification by cleaving companion proteins to low-molecular-weight products. Analysis with model substrates of the several specific activities that were originally present revealed that only the activity against Nalpha-acetyl-L-tyrosine ethyl ester was demonstrable after incubation for 100 hr in the denaturant. After a moderate loss within the first 24 hr, the remaining activity against this ester was conserved for many days thereafter. Pronase was routinely incubated for 1 week at 22 degrees in 6 M guanidinium chloride at pH 8.0 where the esterases showed maximal activity. Analysis of the products of incubation revealed unexpectedly the presence of two serine proteases that were easily separated. After purification to homogeneity these components proved themselves to be the previously demonstrated subtilisin-like and stable chymotrypsin-like enzymes. The only amino-terminal residue of the chymotrypsin-like enzyme is isoleucine, as it is in the earlier, conventionally purified product. The migration of the single band of this enzyme during acrylamide gel electrophoresis was the same whether purified by the past or present technique. No free amino-terminal group was demonstrable in the subtilisin-like enzyme. This study presents a unique and rapid technique for isolation of these proteases, with the first reported purification to homogeneity of the subtilisin-like component. These enzymes may be useful as probes for local relaxations of conformation in substrate proteins. Furthermore, they may contribute to the preparation of enzyme-free non-protein macromolecules.
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PMID:Self purification of two serine endopeptidases. 450 75


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