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: C01B12 .4
471,332 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several inhibitors for trypsin and chymotrypsin were detected in seeds of Vicia faba by isoelectric focussing. Their isoelectric points are at pH 8.5 (main peak with shoulder), at pH 9.1 (minor peak with shoulder) and in the range of pH 9.1-6.4 (several minor peaks with significant lower activities). From the mixture of inhibitors obtained by affinity chromatography on carrier bound trypsin, three inhibitors were isolated by preparative electrophoresis in polyacrylamide gel. On electrophoresis these inhibitors behaved uniformly at pH 9.2 and at pH 4.0. Their molecular weights are about 6000 daltons. The amount of basic amino acids is high, while methionine and isoleucine are absent. Beside of trypsin and chymotrypsin some serine proteinases of microbiol origin are inhibited. The thermal stability is quite high. The Vicia inhibitors therefore differ significantly from the Phaseolus inhibitors in several properties.
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PMID:[Inhibitors for trypsin and chymotrypsin in seeds of the broad bean (Vicia faba) (author's transl)]. 83 41

The complete amino acid sequence of phosphlipase A2 (EC 3.1.1.4) from horse pancreas was determined. The protein controls of a single polypeptide chain of 125 amino acids and has a molecular weight of 13,927. The chain is crosslinked by seven disulfide bridges. The sequence was determined by automated Edman degradation of the intact protein and several of the large peptide fragments. Smaller peptides were analyzed by manual Edman degradation. Fragmentation of the peptide chain was accomplished by enzymatic digestion with trypsin, chymotrypsin, and thermolysin. The final overlap was found by digestion of the polypeptide with a staphylococcal protease specific for glutamoyl bonds. Phospholipase A2 from horse pancreas shows homology to snake venom phospholipases A2 and to the enzyme from porcine pancreas, provided that the published amino acid sequence of the porcine phospholipase A2 is revised to some extent.
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PMID:Amino acid sequence of phospholipase A2 from horse pancreas. 83 12

Measurement of volume, pressure, and length were made on eight segments of human cerebral arteries perfused with chymotrypsin (CT) (EC 3.4.21.1) solution (pH = 7.8) for no more than 19 h, and on nine arterial segments perfused with combined enzyme (CT, trypsin (EC 3.4.21.4), elastase (EC 3.4.21.11)) solutions (pH = 7.8) for no more than 4 h. Circumferential tension-strain (and absolute radius) curves were obtained through the Law of Laplace (tension = pressure X radius). Initial and final elastances (tension/strain) were calculated after 0, 0.5, 1.0, 2.0, and 4.0 h of perfusion under the combined enzyme category, and after 0, 0.5, 1.0, 2.0, 4.0, 6.0, and 19.0 h of perfusion with CT. The initial elastance showed a significant increase (0.02 less than p less than 0.05) after about 6 h of perfusion. Increases in the final elastance became significant only after prolonged periods of perfusion with CT. Histological studies using light and scanning electron microscopy confirmed the removal of the elastic lamina as well as portions of the medial region. Fragmentation of the internal elastic lamina did not appear to affect the distensibility of major cerebral arteries in the 50- to 80-year-old age group.
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PMID:The effects of enzymatic digestion on the elastic properties of isolated human cerebral arteries. 87 50

alpha-Chymotrypsin (EC 3.4.21.1)-catalysed syntheses of peptides were performed with various N-acylated amino acid or peptide esters as donors, and amino acid derivatives, peptides or their derivatives as acceptors. Under optimal conditions the synthesis was almost quantitative. As acceptor nucleophiles, free amino acids or the ester derivatives were inadequate, but amino acid amides or hydrazides, di- or tri-peptides, or the amides, hydrazides and esters of the peptides were useful. The nucleophile specificity for synthesis was markedly similar to the leaving-group specificity in hydrolysis; hydrophobic or bulky amino acid residues were most effecient at both P1' and P2' positions [notation of Schechter & Berger (1967) Biochem. Biophys. Res. Commun. 27, 157-162], but L-proline as well as D-amino acid residues were the worst choices. The synthesis was further dependent on the solubility of the products synthesized; a higher yield of products was expected with lower solubility. As donor esters, good substrates were all useful. Accordingly, fragment condensation was possible by using N-acylated peptide esters and various peptides. The present study suggested that alpha-chymotrypsin may become a useful tool for peptide synthesis.
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PMID:alpha-Chymotrypsin as the catalyst for peptide synthesis. 88 Feb 16

At 20 degrees C, aflatoxin B1, at a sublethal dose, decreases the activity of alkaline phosphatase (EC 3.1.3.1), alpha-glucosidase (EC 3.2.1.20), esterase (EC 3.1.1.1), chymotrypsin (EC 3.4.21.1), leucine aminopeptidase (EC 3.4.11.1), and phosphoamidase (EC 3.9.1.1) biosynthesis in Bacillus thuringiensis (Berliner). In contrast, at 41 degrees C no significant decrease was observed. At this temperature, the mycotoxin is not destroyed or metabolized and bacterial cells are resistant to the toxin.
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PMID:[Effect of aflatoxin B1 on the enzymatic activities of Bacillus thuringiensis (Berliner)]. 88 28

Water-soluble poly(N-vinylpyrrolidone) of molecular weight 10 000 was modified by hydrolysis of 5% of the gamma-lactam rings, and formation of the N-hydroxysuccinimidester. This activated polymer was bound covalently to trypsin (EC 3.4.21.4) and chymotrypsin (EC 3.4.21.1) to complexes of a molecular weight of about 150 000. The bound enzymes showed an increase in stability towards autolysis. Towards small molecular weight substrates the trypsin-poly (N-vinylpyrrolidone) conjugate showed an increase in specific activity of 1: 1.6, whereas the activity towards larger substrate was found to be only 20%. Chymotrypsin-poly(N-vinylpyrrolidone) showed decreased activity against small (50%) and large (7%) molecular weight substrates.
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PMID:Preparation and properties of trypsin and chymotrysin coupled covalently to poly (N-vinylpyrrolidone). 88 41

The amino acid sequence of an active fragment of potato proteinase inhibitor IIb was determined by the Edman degradation procedure and the carboxypeptidase technique. Analyses were carried out on peptides derived from the reduced and carboxymethylated active fragment by digestion with trypsin and chymotrypsin. The active fragment consisted of a single polypeptide chain of 40 amino acid residues including 6 half-cystine residues. Degradation of the intact active fragment by trypsin and subtilisin at pH 6.3--6.4 yielded 3 cystine-containing peptides, and sequence analyses of these peptides revealed that the three disulfide linkages are located between Cys(2) and Cys(16), Cys(6) and Cys(28), and Cys(12) and Cys(38). The reactive site peptide bond of inhibitor IIb, a Lys-Ser bond, is located between positions 26 and 27. The overall sequence of the active fragment is compared with that of an active fragment of inhibitor IIa and the "structure-specificity" relationships of both are discussed. Correlation of the fragments to a naturally-occurring low molecular weight inhibitor is also discussed.
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PMID:Amino acid sequence of an active fragment of potato proteinase inhibitor IIb. 92 94

1. An anionic and a cationic chymotrypsin (EC 3.4.21.1) were isolated from the pancreas glands of the moose (Alces alces) and elk (Cervus elaphus). The A and B chymotrypsins from each species were purified to homogeneity by (NH4)2SO4 fractionation, affinity chromatography on 4-phenylbutylamine-Sepharose and ion-exchange chromatography on DEAE- and CM-cellulose. 2. The molecular weight and pH optimum of each chymotrypsin were similar to those of the corresponding ox A and B chymotrypsins. 3. The substrate specificities of the chymotrypsins were investigated by digestion of glucagon and the oxidized B chain of insulin. The primary specificity of each chymotrypsin for aromatic amino acid residues was further established by determining the Km and kcat for the hydrolysis of a number of synthetic amino acid ester substrates. 4. The amino acid composition and total number of residues of moose and elk chymotrypsin A were similar to those of ox chymotrypsin A. An even greater similarity was observed among the B chymotrypsins of the three species. 5. The A chymotrypsins of moose and elk were fragmented to their constituent 'A', 'B' and 'C' polypeptide chains by succinylation (3-carboxypropionylation), reduction and alkylation of the native enzymes. In each case, the two major chains ('B' and 'C') were separated and isolated. By comparison of the amino acid compositions of moose, elk and oxy 'B' and 'C' chains, a greater difference was observed among the three A chymotrypsins than was suggested by the amino acid compositions of the native enzymes alone. 6. Peptides were isolated from the disulphide bridge and active-site regions of the A and B chymotrypsins of moose and elk by diagonal peptide-'mapping' techniques. From the amino acid compositions of the isolated peptides (assuming maximum homology) and from a comparison of diagonal peptide 'maps', there was established a high degree of primary-structure identity among the mooae, elk and ox chymotrypsins. Tentative sequences were deduced for the peptides isolated by diagonal peptide 'mapping'. 7. Details of the isolation procedures of the moose and elk chymotrypsins A and B and the amino acid analyses of some peptides obtained by diagonal peptide 'mapping' have been deposited as Supplementary Publication SUP 50064 (27 pages) at the British Library Lending Division, Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1976) 153, 5.
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PMID:Chymotrypsins from the deer (Cervidae) family. Isolation, partial characterization and primary-structure studies of chymotrypsins A and B from both moose (Alces alces) and elk (Cervus elaphus) pancreas. 94 18

The 5-dimethylaminonaphthalene-1-sulfonyl group was specifically introduced into the active site region of the serine proteinases: alpha-chymotrypsin, trypsin and subtilisin Carlsberg by the method of affinity-labeling. The resulting fluorescent derivatives were studied by a variety of fluorescence techniques and the results were correlated with structural data available on these enzymes from X-ray analysis. As model compounds for the Dns-proteinases, the absorption and fluorescence properties of Dns-amide and Dns-ethyl ester were studied in ethanol/water and p-dioxane/water mixtures. The fluorescence emission transtion energies and quantum yields were related to four commonly employed solvent-polarity scales. Best correlations for different solvents were obatined with the empirical "Z" and "Y" scales. From inspection of the fluorescence emission transition energies of the Dns group in the Dns-proteinases and comparision with the model compound studies it was possible to assign "Z" values for the apparent microenvironment polarities of the Dns group in the Dns-proteinases. The apparent polarities of the microenvironments of the Dns group in Dns-Ser 195-chymotrypsin (Dns-chymotrypsin (I)); (Dns-Phe-CH2)-His 57-chymotrypsin; (Dns-Lys-CH2)-His 46-trypsin; and Dns-Ser 221--subtilisin Carlsberg (Dns-subtilisin (I)) are in the range of 89.5-92.5 on the "Z" scale. The apparent microenvironment polarity of the Dns group in Dns-Ser 183-trypsin (Dns-trypsin (I)) appears to be below 76.7 on the "Z" scale. The Dns group in Dns-chymotrypsin (I) and (Dns-Phe-CH2)-His 57-chymotrypsin appears to be rigidly bound as evaluated by fluorescence polarization studies. The effect of 2H2O on the fluorescence emission quantum yields of Dns-amide and Dns-ethyl ester was examined. In both cases the ratios of quantum yields in 2H2O:ethanol (8:2) to quantum yields in H2O:ethanol (8:2) was about 1.8. The 2H2O effect upon the fluorescence emission quantum yields of the Dns group has been used to investigate solvent accessibility of this chromophore in the Dns-proteinases. Acessibility studies using 2H2O are very promising and have some definite advantages over other existing methods. Energy transfer between the Trp residues and the bound Dns group was investigated in the Dns-proteinases. The mean transfer distance calculated from the observed transfer efficiencies are 18.1 A, 19.7 A and 18.4 A for (Dns-Phe-CH2)-His 57-chymotrypsin, Dns-chymotrypsin (I) and (Dns-Lys-CH2)-His 46-trypsin, respectivly. From models built using X-ray crystallographic coordinates for the protein atoms, the mean distance of separation between the Trp residues and the bound Dns group for the same set of conjugates ar 18.6 A, 17.5 A and 17.5 A, respectively. Considering the inherent difficulties in energy transfer studies, the results are in excellent agreement with the X-ray data.
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PMID:Specific fluorescent derivatives of macromolecules. A fluorescence study of some specifically modified derivatives of chymotrypsin, trypsin and subtilisin. 95 53

The specific cyanate reagentN-acetyl-p-cyanato-L-phenylalanine ethyl ester (compound 1) was synthesized in an attempt to selectively modify the binding pocket of chymotrypsin (EC 3.4.21.1) while leaving the catalytic residues un touched. The reagent reacts with chymotrypsin to yield chiefly an inactive derivative 3a, with the active site Ser-195 carbamylated and the alpha-amino group, with the reagent 1 yields a modified enzyme(compound 4) with an additional carbamyl group on Ser-195.Neither derivative 3a nor 4reacts with diisopropylfluorophosphate under conditions where chymotrypsinogen is modified, indicating that Ser-195 is altered. Both derivatives 3a and 4 are retained on a 4-phenylbutylamine affinity colomn demonstrating that the substrate binding pocket is intact in both derivatives. The results indicate the potential value of aryl cyanates as protein reagents for the selective modification of nucleophilic sites. However, it is apparent that reaction at unreactive residues in the binding pocket of chymotrypsin with cyanates or similar reagents will require blockage of the more nucleophilic catalytic residues.
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PMID:Modification of chymotrypsin with the specific cyanate reagent N-acetyl-p-cyanato-l-phenylalanine ethyl ester. 95 38


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