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)

Three cationic proteins from the granules of human neutrophil granulocytes were obtained in a high degree of purity be means of affinity chromatography on 4-phenylbutylamine-Sepharose. Together with lysozyme, the three cationic proteins exhibit the highest electrophoretic mobility toward the cathode in acrylamide gels at moderately acid pH, among the granule constituents that are solubilized in 0.1 M phosphate buffer, pH 7.0, containing 1 M NaCl. The three cationic proteins represent a group of "neutral proteases" distinct from elastase and collagenase. They hydrolyze casein, azocasein and the chymotrypsin substrate N-acetyl-L-tyrosine ethyl ester. Optimal activity is found at pH 7.4-7;5. The enzymes are inhibited by the specific chymotrypsin inhibitor N-tosyl-L-phenylalanylchloromethane and by the naturally occurring inhibitors alpha-antichymotrypsin, alpha-1-antitrypsin, as well as by the trypsin inhibitors from soy beans and limabeans.
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PMID:Cationic proteins from human neutrophil granulocytes. Evidence for their chymotrypsin-like properties. 23 18

A protein phosphokinase (EC 2.7.1.1.37) was isolated from baker's yeast (Saccharomyces cerevisiae) after a 17,000-fold purification; the purified enzyme is homogeneous according to the criteria of gel electrophoresis and ultracentrifuge analysis. The enzyme has a high isoelectric point of ca. 9 and appears to exist as a monomer with a molecular weight of 42,000 plus or minus 1500. It is neither stimulated by cyclic 3',5'-AMP, -GMP, -CMP or -ump nor inhibited by the regulatory subunit of rabbit muscle protein kinase (Reimann, E. M., Walsh, D. A., and Krebs, E. G. (1971), J. Biol. Chem. 246, 1986). In the presence of divalent metal ions, preferably Mg-2+ or Mn-2+, the enzyme readily transfers the terminal phosphate group of ATP to phosvitin, alphaS1B- and beta a-casein and an NH2-terminal tryptic peptide derived from beta a-casein, but not to protamine, lysine, or arginine-rich histones or to yeast enzymes such as phosphorylase, phosphofructokinase, or pyruvate carboxylase; serine and polyserine were also inactive as phosphate acceptors. Km values of 0.17 mM for beta a-casein and 0.2 mMfor ATP were determined at 10 mM Mg-2+. The urified yeast protein kinase also catalyzes the reverse reaction, namely, the transfer of phosphate from fully phosphorylated beta a-casein or its NH2-terminal peptide to ADP resulting in the formation of ATP. AMP, GDP, UDP, and CDP did not serve as phosphate acceptors in this reaction. As observed by Rabinowitz and Lipmann (Rabinowitz, M., and Lipmann, F. (1960), J. Biol. Chem. 235, 1043) both reactions have different pHoptima with values of 7.5 for the forward reaction (phosphorylation of the proteins) and ca 5.2 for the formation of ATP; both are differently affected by salts. Phosphorylation of beta a-casein with [gamma-32-P]ATP followed by digestion of the labeled protein with trypsin indicated that all the radioactivity was exclusively introduced in an NH2-terminal peptide possessing the unique sequence: Glu-Ser(P)-Leu-Ser(P)-Ser(P)-Ser(P)-Glu-Glu...(Ribadeau-Dumas, B., Brignon, G., Grosclaude, F., and Mercier, J.-C. (1971), eur J. Biochem. 20, 264). By subjecting beta a-casein and its NH2-terminal peptide to the combined action of almond acid phosphatease and purified yeast protein kinase, it was determined that the phosphorylation and dephosphorylation reactions proceed randomly, i.e., all seryl phosphate residues are equally susceptible and that the rate of phosphorylation decreases drastically as the number of bound phosphate groups in the substrate diminishes.
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PMID:Purification and properties of a yeast protein kinase. 23 75

The rate of protein enzymatic degradation in a mixture is slower than that of single proteins. In a mixture of haemoglobin or casein with protamine, the release of tyrosine by trypsin and chymotrypsin A is slower. A slower rate in the release of arginine from protamine occurs only in mixtures with haemoglobin. The inhibition of enzymatic degradation of proteins in a mixture is due to formation of intermolecular associations and to changes in their spacial structure.
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PMID:Enzymatic degradation of protein mixtures. 23 2

Granule and post-granular-supernatant fractions were obtained from pig leucocyte cells by differential centrifugation in 0.34 M sucrose. Granule extract possesses proteinase activity at acid and at neutral pH. Three groups of neutral and a group of acid proteinases were isolated from granule extracts by chromatography on DEAE-cellulose. In the first group are present elastase-like and plasminogen-activator proteinases, that are inhibited by diisopropylphosphorofluoridate, alpha1-antitrypsin, intracellular leucocyte inhibitor and partly with p-aminomethylbenzoic acid and Trasylol. The second group of neutral proteinases is unstable under the conditions of isolation used the third group of neutral proteinases comprises collagenases that are inhibited by ethylenediamine tetraacetic acid disodium salt, alpha1-antitrypsin and leucocyte inhibitor. The acid proteinases are inhibited only with pepstatin, up to 90%. In the post-granular supernatant was found the acid proteinase activity towards hemoglobin and casein, and non-stable neutral proteolytic activity towards bovine serum albumin and serum gamma globulin. In the post-granular supernatant also the inhibitors of neutral proteinases were found. By gel filtration on Sephadex G-100 and ion-exchange chromatography on CM-cellulose two inhibitors of neutral proteinases were isolated. The majority of the inhibitor capacity (about 80%) of post-granular supernatant was eluted together with ovalbumin (Mr 43000) and the remainder with cytochrome c (12300). These inhibitors inhibit the granule neutral proteinases, acting on all substrates used, but do not inhibit granule acid proteinase. Inhibition effects of post-granular-supernatant inhibitors on trypsin and chymotrypsin were obtained only when bovine serum albumin was used as substrate. Inhibitors of post-granular supernatant are stable at pH 6-8, but unstable in the pH rnage 2-5 and are thermolabile.
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PMID:Intracellular distribution of neutral proteinases and inhibitors in pig leucocytes. Isolation of two inhibitors of neutral proteinases. 24 Jul 15

Using an in vitro procedure, with both plant (gluten and edestin) and animal proteins (egg white and casein) as ratio of protein substrate to enzymes (pepsin, trypsin, erepsin) was increased in progressive stages, there was a change in the amino acids released; the proportions of some amino acids progressively increased, others progressively decreased while still others remained constant. The pattern of amino acids released was distinct for each protein and as substrate increased relative to enzymes, certain amino acids essential for the human increased with some proteins and decreased with others which suggests nutritional implications. The variations in amino acids released with changes in ratio of substrate to enzymes was not a random effect but an apparent orderly process. The phenomenon is termed "variable ratio effect".
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PMID:Effect of ratio of enzymes to substrate on amino acid patterns released from proteins in vitro. 34 48

When the cell wall of Bacillus subtilis is removed by lysozyme and the resultant protoplasts are plated on hypertonic soft agar medium, each protoplast forms an L colony. L bodies from such L colonies again plate as L-colony-forming units (CFU). However, if protoplasts or L bodies are "conditioned" by 1 h of incubation in 0.4% casein hydrolysate medium and then incubated in 25% gelatin medium for 1 h, 60 to 100% of the formerly naked cells give rist to bacillary colonies. The present experiments largely explain the mechanism responsible for the "heritable" persistence of the wall-less state in B. subtilis. It is shown that protoplasts produce a reversion inhibitory factor (RIF) which blocks reversion when the cell concentration exceeds 5 x 105 CFU/ml. This inhibitor is nondialyzable and sensitive to trypsin, heat, and detergent. Efficient reversion at 2 x 107 CFU/ml is obtained if the protoplasts are treated with trypsin after conditioning and chloramphenicol is incorporated into the gelatin reversion medium. In the presence of 500 mug of trypsin per ml, the requirement for gelatin is sharply reduced, and reversion occurs rapidly in liquid medium containing only 10% gelatin. Trypsin also stimulates reversion in L colonies growing on soft agar. Latent RIF is activated by beta-mercaptoethanol. This reagent blocks reversion of protoplast suspensions at densities of 5 x 105 CFU/ml. Comparison of the autolytic behavior of B. subtilis and of the RIF revealed that several or the properties of the two activities coincide: both are inhibited by high concentrations of gelatin, both are activated by beta-mercaptoethanol, and both have high affinity for cell wall. Going on the assumption that RIF is autolysin, models for protoplast reversion is suggested by the finding that mutants with altered teichoic acid show altered reversion behavior.
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PMID:Inhibitory protein controls the reversion of protoplasts and L forms of Bacillus subtilis to the walled state. 40 56

Trypsin inhibitor from sow colostrum was isolated by ion exchange chromatography on DEAE-Sephadex A-50 followed by gel filtration chromatography on Sephadex G-100 and affinity chromatography. Antiserum against sow colostrum trypsin inhibitor was produced by immunization with the purified inhibitor, and made specific by absorption with normal porcine serum. The specific antiserum was used for immunoquantitation by single radial immunodiffusion (SRI). In sow colostrum whey, good agreement was found between the results obtained by SRI and the total trypsin-inhibiting activity as determined by radial diffusion in a casein-containing agarose gel (r = 0.97, n = 10). In sow's milk there was only a very low inhibiting activity, and no colostral inhibitor was demonstrable by SRI. Also in baby-pig urine agreement was found between the two methods (r = 0.97, n = 14). In baby-pig serum such an agreement was not seen, undoubtedly becuase of the presence of genuine serum trypsin inhibitors. By the SRI technique it is possible specifically to determine the colostral inhibitor even in the presence of other trypsin inhibitors.
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PMID:Isolation and immunochemical determination of sow colostrum trypsin inhibitor. 41 13

Cercariae of Echinostoma revolutum encysted in the kidney of the snail Physa heterostropha within 1 hr and on mucus trails from Helisoma trivolvis, P. heterostropha and Lymnaea sp. within 2 hr. Significantly, more normal cysts were formed in mucus of Helisoma than in mucus of Physa or Lymnaea. Optimal, in vitro encystment occurred within 24 h in either Locke's 1 : 1 or Locke's 1 : 1 + 1% glucose. Significantly more normal cysts occurred in the Locke's 1 : 1 medium. Both normal and abnormal cysts from Lock's media and snail mucus excysted in an alkaline bile trypsin medium. Cercariae did not encyst in Lock'e media supplemented with casein hydrolysate or in agar cultures containing various chemicals.
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PMID:Studies on encystment of Echinostoma revolutum cercariae. 44 97

The cleavage specificity of a protease from Thermoactinomyces vulgaris (thermitase) was determined by the insulin B-chain and the cleavability of casein and haemoglobin by this enzyme as compared to other proteases (trypsin, chymotrypsin, proteases from Bac. megaterium and cytophages). The most intense splitting effect on the substrates under investigation (insulin B-chain, casein and haemoglobin) is exerted by thermitase, i. e., the unspecificity of this enzyme is especially marked.
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PMID:[Substrate specificity of a protease from Thermoactinomyces vulgaris]. 46 Mar 96

Two methods were used to immobilize trypsin on the polyurethane carrier on the basis of toluylenediisocyanatepolyoxypropylene glycol due to interaction between the lyzine free amino groups and the enzyme arginine guanidine group and the prepolymer isocyanate group. The amount of the enzyme chemically bound by the two methods is about 50 and more than 70%, respectively. The substrate specificity of the initial and washed samples of the immobilized trypsin was studied with respect to three highly molecular substrates with different molecular weight and different charges--protamine, casein, hemoglobin. It is shown that independently of the method of binding the activity of the immobilized trypsin is the highest with respect to hemoglobin and is the lowest with respect to protamine. The samples of trypsin immobilized on the polyurethane carrier may be used in biology and medicine when creating the prolonged forms of the enzymic preparations.
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PMID:[Production and properties of trypsin immobilized on a polyurethane matrix]. 47 83


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