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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 is specifically adsorbed at low ionic strength and alkaline pH to hydroxyalkyl methacrylate gels with N-benzyloxycarbonylglycl-D-phenylalanine or N-benzyloxycarbonylglycyl-D-leucine attached through 1,6-hexanediamine. Chymotrypsin is not adsorbed either to the unmodified gel (Spheron) or to the gel with attached, 1,6-hexanediamine (NH2-Spheron). The adsorption of chymotrypsin to Z-Gly-D-Phe-NH2-Spheron was investigated as a function of pH and ionic strength. Trypsin is not adsorbed to this gel. Chymotrypsin isolated from a crude pancreatic extract by affinity chromatography on Z-Gly-D-Phe-NH2-Spheron had the same activity as the enzyme isolated on a column of Spheron, to which the naturally-occurring trypsin inhibitor had been coupled.
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PMID:Affinity chromatography on hydroxyalkyl methacrylate gels. III. Adsorption of chymotrypsin to poly(hydroxyalkyl methacrylates) with covalently bound benzyloxycarbonyl-glycyl-D-phenylalanine and -D-leucine as function of pH and ionic strength. 0 31

Chymotrypsin has been immobilized to several nonporous magnetic materials. Nickel particles were considered to be most suitable as immobilized enzyme supports. Chymotrypsin immobilized to nonporous magnetic supports was not fouled significantly by either whole milk or clarified yeast homogenate. AE-cellulose-chymotrypsin was rapidly fouled by both these materials and chymotrypsin immobilized to acrylic-based ion exchangers was slowly fouled. Immobilized enzyme activity was found to be inversely proportional to particle diameter for nonporous rock magnetic particles. Immobilization by adsorption and then glutaraldehyde crosslinking was used to produce controlled amounts of chymotrypsin on the particles. Esterolytic activity increased with enzyme loading but caseinolytic activity did not increase. Chymotrypsin is inhibited by metal ions from the magnetic supports. It is partially protected by use of a preliminary protein coating and may be reactivated by incubation with EDTA or BSA.
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PMID:Nonporous magnetic materials as enzyme supports: studies with immobilized chymotrypsin. 1 43

Tosyl-triethylenetetramine-Sepharose (Tos-T-Sepharose) and carbenzoxytriethylenetetramine-Sepharose (Z-T-Sepharose) were found to be adsorbents utilizable in the purification of several microbial and animal proteases. The former Sepharose derivative adsorbed alpha-chymotrypsin, trypsin, subtilisin, thermolysin and neutral subtilopeptidase at neutral pH range, and acid proteases such as pepsin and Rhizopus niveus protease at pH 3.5-6.5. alpha-Chymotrypsin and trypsin were eluted with 0.1 N acetic acid and Rhizopus protease with 0.5 N acetic acid, thermolysin with 1 M guanidine-HCl or 33% ethyleneglycol, whilst pepsin was recovered by elution with 2 M guanidine-HCl at pH 3.5. The binding of neutral subtilopeptidase and subtilisin to this adsorbent was comparatively weak and both the enzymes were recovered by elution with 0.5 M NaCl at neutral pH. On the other hand, Z-T-Sepharose was found to bind tightly to these proteolytic enzymes except neutral subtilopeptidase. Trypsin and alpha-chymotrypsin were released from the adsorbent column with 1 M p-toluenesulfonate, and subtilisin with 1 M guanidine-HCl or 33% ethyleneglycol at neutral pH region. By these chromatographic procedures, the specific activities of these proteolytic enzymes increased effectively. Comparison of the binding abilities of acetyl-, benzoyl-, tosyl- and carbobenzoxy-T-Sepharoses to these enzymes suggests that hydrophobicity of tosyl and carbobenzoxy groups plays an important role in the enzyme-adsorbent interaction.
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PMID:Purification of several proteolytic enzymes by tosyl- and carbobenzoxy-triethylene-tetramine-sepharoses. 1 98

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

In the course of preparing aryl azide derivatives for use as photoprobes, we have observed significant light sensitivity in the precursor aryl diazonium compounds. The photosensitive properties of this class of compounds are of interest since they will seek out cationic binding sites in biological targets, and can be employed to inhibit complementary targets at acid pH. The relationship between photolytic change in the structure of diazonium compounds and the corresponding change in function of a biological target are presented. Experiments are described in which the dark and light sensitive properties of a model diazonium compound, diazobenzene sulfonate (DBS), were determined. The ultraviolet spectra were used to evaluate the dark stability and light sensitivity of DBS. Chymotrypsin and trypsin served as functioning targets for further evaluation of the photochemical properties. Both enzymes are stable to the probe in the dark at acid pH. A rapid loss of enzyme activity was observed following flash photolysis of DBS-enzyme solutions. Photolytic incorporation of radioactive DBS into chymotrypsin was observed. Aryl diazonium salts can be employed to probe the availability of complementary sites in biological targets at different acid pH values.
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PMID:Photolytic inhibition and labeling of proteins with aryl diazonium compounds. 2 42

A trypsin inhibitor was purified from the tubers of Colocasia antiquorum. The inhibitor acted on bovine trypsin, human trypsin and weakly on bovine chymotrypsin. The inhibitor, which had a molecular weight of 40 000, contained trace amounts of carbohydrates. The purified inhibitor was stable over a pH range of 2.0--12.0 and was more thermostable than the crude preparations. Trinitrobenzene sulphonate treatment resulted in the inactivation of the inhibitor. Chymotrypsin, pepsin and pronase digested the inhibitor. Pretreatment with trypsin at neutral pH resulted in the partial loss of antitryptic activity, whereas treatment at pH 3.7 led to complete inactivation. Evidence for the formation of a trypsin-inhibitor complex at pH 7.6 is provided. During the plant growth, in the early phase (0--40 days) there was a gradual increase in protein content and in antitryptic activity. The middle phase (40--55 days) was characterized by a rapid fall and abolition of the antitryptic activity and a diminution in protein content in the tubers. The immature tubers had low antitryptic activity compared to the mature ones. Mild heat treatment caused a sharp rise in antitryptic activity in the extracts of immature tubers but not with the mature tuber preparations.
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PMID:Natural plant enzyme inhibitors. VI. Studies on trypsin inhibitors of Colocasia antiquorum tubers. 3 37

alpha-Chymotrypsin [EC 3.4.21.1] catalyzed the syntheses of peptide bonds with various N-acylated amino acids or peptides having aromatic or hydrophobic amino acid residues at the C-terminal position as carboxyl components, and amino acid derivatives, peptides or their derivatives as amine components. A neutral pH was most efficient and quite high concentrations of alpha-chymotrypsin and starting materials were required for synthesis. Four amine components, hydrophobic or bulky amino acid residues were useful at the N-terminal position. Stereospecificity was also observed at the N-terminal position of amine components. Peptide synthesis was not usually seen when the products were soluble in the reaction mixture. This could be partly overcome by increasing the concentration of either the carboxyl or the amine component to more than ten times that of the other.
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PMID:Peptide bond synthesis catalyzed by alpha-chymotrypsin. 3 79

Analysis of platelet membrane proteins and glycoproteins by SDS polyacrylamide gel electrophoresis was carried out before and after treatment with thrombin. Extended incubation with thrombin (in the presence of EDTA or adenosine, which inhibit aggregation) produced extensive changes in the bands observed. With incubation times of a few minutes however, the changes were restricted to a glycopeptide, GP IV (approx. 90,000 Daltons) and one or two polypeptides of low molecular weight, in particular polypeptide 16 (approx. 23,000 Daltons). At 0--3 degrees C only polypeptide 16 was still hydrolyzed. Chymotrypsin, which does not activate platelets, attacked glycopeptides I, II, III but no changes were apparent in GP IV and polypeptide 16. When chymotrypsin-treated platelets were further incubated with thrombin, only GP IV and one to two low molecular weight polypeptides, especially polypeptide 16, were affected. As polypeptide 16 appears to be an integral membrane component it is possible that it, either by itself or in combination with GP IV, represents the primary thrombin substrate involved in platelet activation. Aggregated IgG, which also activates platelets, does not modify the membrane glycoproteins but does change the low molecular weight region in particular band 16.
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PMID:Effects of thrombin, chymotrypsin and aggregated gamma-globulins on the proteins of the human platelet membrane. 7 80

1. Bovine (Bos taurus) trypsin and trypsin activity in rat (Rattus norvegicus) pancreatic extract were inhibited by soybean trypsin inhibitor and by bovine basic pancreatic and colostrum inhibitors. 2. Bovine alpha-chymotrypsin was inhibited by soybean and bovine basic pancreatic inhibitors but only weakly by colostrum inhibitor. 3. Chymotrypsin activity in rat pancreatic extract was due to at least three different components against all of which the inhibitors were largely ineffective. 4. It is concluded that bovine colostrum inhibitor has a more limited inhibition spectrum than the phylogenetically related basic pancreatic inhibitor which, in turn, is less active against rat than against bovine enzymes.
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PMID:Inhibition of rat and bovine trypsins and chymotrypsins by soybean, bovine basic pancreatic, and bovine colostrum trypsin inhibitors. 9 86

Trypsin (T) and chymotrypsin (CHT) activities in luminal contents of the ileum, caecum and sigmoideum were followed in conventional (6 animals), monoassociated (5) and germfree (5) rabbits by pH-stat automatic titration using p-toluenesulphonyl-L-arginine methylester and acetyl-L-tyrosine ethylester as substrates. In conventional rabbits with complete microbial flora an aborally increasing decline of both proteolytic activities of luminal contents was determined (ileum T 198.2 - CHT 100.0; signmoideum T 10m.2 - CHT 68.8 mrg/g of intestinal content). Monoassociated animals represent a group different from both germfree and conventional animals. Trypsin and chymotrypsin of intestinal contents were not significantly altered by the presence of megacaecum in germfree rabbits (ileum T 219.2 - CHT 160.2; sigmoideum T 208.8 - CHT 110.8 mug/g of intestinal content). Chymotrypsin in the intestinal contents appears more labile and more affected by microbial flora than trypsin.
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PMID:Trypsin and chymotrypsin activity of the intestinal content in germfree, monoassociated and conventional rabbits. 13 38


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