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)

Chymotrypsin-type proteinase is detected in the proteolytic system of Asp. oryzae. The action of it and chymotrypsin is shown to depend on formaldehyde. Hydrolysis of substrates, p-nitrophenyl acetate (p-NPA) and N-benzoyl-tyrosine methyl ether (BTME), by both preparations is almost the same. The obtained activity pH-optimum for the studied proteinase esterolytic activity is located in the alkaline zone as well as for crystalline chymotrypsin (substrate p-NPA). It concerns pH of both enzymes stability as well. The enzyme under study is relatively labile. At 50 degrees C there are only traces of the activity in the medium with p-NPG. Its considerable decrease is observed at 40 degrees C. This type activity is more stable on the substrate BTME. 10 min later it disappears completely in the enzymic preparation at a temperature of 60 degrees C at 40 degrees C it is 96.8%. For 24 h at 25 degrees C the activity lowers only by 8%. Crystalline chymotrypsin is stable under these conditions. DEAE-cellulose chromatography (different types of elution) detected multiple forms of proteinase differing in solubility chromatographic properties and specific activity when splitting the substrates p-NPA, BTME and casein.
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PMID:[Properties of chymotrypsin proteinase from Aspergillus oryzae]. 1 30

Chemical modifications of human plasma alpha1-antitrypsin with reagents which modify lysyl residues (citraconic anhydride, acetic anhydride, formaldehyde and 2,4,6-trinitrobenzenesulfonic acid) and arginyl residued (1,2-cyclohexanedione) were examined with regard to their effect upon the elastase inhibitory capacity of the glycoprotein. 2,4,6-Trinitrobenzenesulfonic acid was employed to quantitate the remaining free amino groups (epsilon-NH2 groups of lysine) and the extent of modifications. Amino acid analysis was utilized in the same capacity for the guanidino groups of arginyl residues. The elastase inhibitory capacity of alpha1-antitrypsin was destroyed following trinitrophenylation, citraconylation and acetylation. Circular dichroism of the native and modified derivatives revealed major changes in conformation following trinitrophenylation and citraconylation while CD profiles of acetylated and reductively methylated derivatives differed from that of the native profile considerably less. Reductively methylated alpha1-antitrypsin retained its elastatse inhibitory capacity. The reaction of 1,2-cyclohexanedione with alpha1-antitrypsin did not effect in a loss in inhibitory capacity. Gel filtration studies of native and modified alpha1-antitrypsin on Sephadex G-100 demonstrated an increased molecular weight presumably through molecular aggregation, in the citraconylated and trinitrophenylated derivatives, but not in the cases of the other derivatives. Based upon these studies and previous investigations of our laboratory, it was concluded that (1) alpha1-antitrypsin is a lysyl inhibitor type (i.e., the reactive site is a Lys-X bond), (2) its interaction with elastase follows a pattern similar to trypsin and chymotrypsin, and (3) the positively charged epsilon-NH2 group of lysine is essential for the maintenance of elastase inhibitory capacity.
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PMID:Circular dichroism of chemically modified human plasma alpha1-antitrypsin. Interaction with porcine elastase. 31 Mar 16

The receptors for aggregated immunoglobulin G (IgG) (an Fc receptor) and for ristocetin-von Willebrand factor on human platelets were studied by means of various modifications of the platelet surface. The expression of these receptors was measured by the agglutination of platelets to ristocetin in the presence of von Willebrand factor, which is part of the factor VIII complex, and by the binding of aggregated IgG coupled to 3H-labelled diazobenzene. Treatment of platelets with chymotrypsin, trypsin, papain and pronase which removed protein and glycoprotein from the platelet under conditions where the release reaction was inhibited caused loss of the expression of the receptor for ristocetin-von Willebrand factor and an enhancement of that for aggregated IgG. Induction of membrane changes with ADP and of the release reaction with the ionophore A23187 abolished agglutination to ristocentin-von Willebrand factor but did not alter the receptor for aggregated IgC. Possible contributions of unspecific membrane changes, produced by protease treatment of platelets, to the modification of receptor expression were eliminated by the use of formaldehyde-treated platelets. Trypsin, papain and pronase destroyed the ability of these platelets to agglutinate to ristocetin-von Willebrand factor but produced no change in the binding of aggregated IgC. Therefore, the receptor for ristocetin-von Willebrand factor is truly sensitive to proteolysis while the Fc receptor is not, but is partially masked by protease-sensitive material.
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PMID:A comparative study of the effect of modification of the surface of human platelets on the receptors for aggregated immunoglobulins and for ristocentin-von Willebrand factor. 31 30

Casein epsilon-aminolysyl residues were converted to the methyl (and dimethyl), isopropyl or cyclopentyl derivatives in high yield with formaldehyde, acetone or cyclopentanone, respectively, in the presence of sodium borohydride. When incorporated into diets at 10% as the sole protein source, the chemically modified caseins failed to support growth of young rats. Methyl casein did, however, support limited growth after about 5 days. Plasma threonine levels increased and lysine levels decreased markedly in rats fed the alkyl caseins. The respective alkyllsine derivatives were present in plasma and urine. In another experiment, nearly normal or normal growth was obtained by feeding lysine-supplemented methyl or isopropyl casein, respectively. A preparation of partially methylated casein, containing approximately equal amounts of monomethyl- and dimethyllysines, supported normal rat growth. These results demonstrate that lysine deficiency was produced by feeding highly alkylated caseins. Digestibility of the chemically modified caseins in vivo was not affected, although in vitro studies with trypsin and alpha-chymotrypsin showed lowered digestibility. Since no apparent toxicity was observed limited methylation of food proteins may be useful for protection of lysyl residues against deteriorative reactions during processing and storage.
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PMID:Effect of reductive alkylation of the epsilon-amino group of lysyl redsidues of casein on its nutritive value in rats. 56 44

Acidic extracts of washed, ejaculated human spermatozoa contain, besides acrosin, two proteinase inhibitors, a trypsin-chymotrypsin (elastase) inhibitor (HUSI-I) and a trypsin-acrosin inhibitor (HUSI-II). Using the indirect immunofluorescence technique these inhibitors could be localized in the spermatozoa. Ejaculated spermatozoa were treated with monospecific antibodies raised in rabbits against HUSI-I and HUSI-II, respectively, and with fluorescein-labeled IgG from goat directed against the rabbit IgG. If acetone-fixed spermatozoa were used, fluorescence appeared only in a small ring near or at the equatorial segment of the spermatozoa. After prefixation of washed spermatozoa with 0.36% formaldehyde, however, distribution of both inhibitors in the region of the acrosomal caps could clearly be demonstrated. Present results suggest that they are attached at the plasma membrane. Obviously, in the case of human spermatozoa the inhibitors are relatively easily detached together with the membrane so that prefixation is necessary to achieve proper localization.
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PMID:Localization of seminal plasma proteinase inhibitors in human spermatozoa as revealed by the indirect immunofluorescence technique. 79 87

Results of the comparative study of trypsin- and chymotrypsin-like serine proteases from pyloric caeca of salmon fishes and trypsin and chymotrypsin of bulls are presented in the paper. The hydrolytic activity of salmon proteases with respect to methyl ethers of N-benzoyl-L-leucine is 2.4 times higher than that of bull chymotrypsin, but with respect to methyl esters of N-benzoyl-L-tyrosine and N-benzoyl-L-arginine the activity of salmon proteases is 6.5 and 80 times lower than that of bull chymotrypsin and trypsin. Salmon proteases in contrast to bull trypsin and chymotrypsin hydrolyze but slightly N-glutaryl-L-phenylalanine para-nitroanilide. It shown that fish proteases are not absolutely specific to synthetic substrates, which is a result of their less pronounced (than in case of bull trypsin and chymotrypsin) differences in structures of binding centres. The study of the salmon protease interaction with some immobilized ligands has confirmed the higher affinity of enzymes to reagents with two space-separated aromatic rings in their composition. It is supposed that salmon proteases interact with such reagents through two sites: hydrophobic "pockets" and probably additional binding site of the active centre. The salmon protease preparation demonstrates higher resistance to inactivating action of formaldehyde within the range of concentrations 2-16% than bull chymotrypsin does.
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PMID:[Comparative study of the properties of serine proteases of lower and higher vertebrates]. 208 90

A sensitive spectrophotometric method for the determination of aspartame in beverages is described. The method involves the enzymic conversion of aspartame into formaldehyde by the alpha-chymotrypsin-alcohol oxidase system, followed by the formation of a chromophore with 4-aminopent-3-en-2-one. The calibration graph was linear in the range 2.0-30.0 micrograms ml-1 of aspartame. Many common ingredients of beverages do not interfere with the proposed method. The method was applied to the determination of the aspartame content of various real samples, and the results obtained were compared with those given by high-performance liquid chromatography.
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PMID:Enzymic method for the spectrophotometric determination of aspartame in beverages. 236 19

The influence of formaldehyde fixation, dehydration and polymethacrylate embedding on the results of immunofluorescence staining of immunoglobulin and enzymehistochemical demonstration of hydrolases, especially acid phosphatase and alpha-naphthylacetate esterase in human tonsils and bone marrow were studied. The best results were achieved by using 2% formaldehyde and 5% sucrose in 0.02 M phosphate buffer (ph 7.4) for fixation and ethyleneglycol monobutylether for dehydration. The procedures were carried out at 4 degrees C. For tissue embedding we used the commercially available polymethacrylate Kalloplast R. The polymerisation was carried out at -20 degrees C for 18 hours. This method permits a good preservation of morphological details and the survival of antigenic determinants and enzyme activity. Trypsin, pepsin and alpha-chymotrypsin were used to "unmask" the antigenic determinants in methacrylate sections. Trypsin and alpha-chymotrypsin revealed comparable results, but because of better practicability we used alpha-chymotrypsin. Using the described fixation, dehydration and embedding procedures it was possible to demonstrate both intracellular immunoglobulins (gamma, alpha and mu heavy chains; kappa and lambda light chains) and surface-bound immunoglobulins (mu and delta heavy chains; kappa and lambda light chains). Comparable results were achieved in human bone marrow biopsies. The results of histochemical demonstration of both enzymes were better in bone marrow sections than in that of the tonsils. We think, that the presented method is suitable in the diagnosis of myelo- and lymphoproliferative disorders on both the bone marrow and lymphatic tissue.
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PMID:[The effect of fixation, dehydration and polymethacrylate imbedding on the results of immuno- and enzymehistochemical studies on lymphatic tissue and bone marrow]. 245 13

A new method for the determination of the artificial sweetener aspartame is described. alpha-Chymotrypsin is used to cleave the methyl ester group of aspartame, producing methanol hydrolytically. The methanol is detected using an electrode which is constructed by physically trapping yeast alcohol oxidase enzyme at the tip of a dissolved oxygen electrode. The decrease in oxygen concentration, which occurs as methanol is enzymatically oxidized to formaldehyde, is measured amperometrically. Aspartame levels in diet soft drinks as determined by the proposed method and by liquid chromatography are in excellent agreement. The relative standard deviation of the measurements is 0.83%. The methanol present in diet cola as a result of aspartame degradation can also be measured by using the electrode without alpha-chymotrypsin.
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PMID:Determination of aspartame in beverages using an alcohol oxidase enzyme electrode. 265 24

Plasmodium berghei sporozoites were observed to react with human hepatoma (HepG2) target cells which had been fixed with methanol, formaldehyde, or glutaraldehyde. The reaction consisted of attachment of sporozoites to the fixed target cells and the release of circumsporozoite protein which bound to target cell areas adjacent to the attachment sites. Treatment of fixed target cells with 0.1 N H2SO4 at 80 C, neuraminidases, neuraminidase plus galactose oxidase or inclusion of transferrin, orosomucoid, their asialo forms, or various monosaccharides in the incubation medium had no significant effect on target cell reactivity with sporozoites. Fixed cells oxidized with periodate or cells extracted with methanol or chloroform-methanol were reactive but lost activity if allowed to air dry after treatment. Treatment with papain or chymotrypsin at levels producing heavy cell structure damage caused a major loss of activity.
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PMID:Plasmodium berghei: reaction of sporozoites with chemically and enzymatically modified hepatoma cells. 301 69


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