Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.25.1 (proteasome)
 28,817 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protease activity was detected in membranes of human bovine erythrocytes prepared by the conventional procedures which include washing and removal of the "buffy layer". The enzyme was extracted by 0.75 M KCNS or (NH4)2SO4 and was activated by 0.4 to 0.5 M of the same salts. Colored, particulate hide powder-azure, membrane fractions and soluble proteins such as hemoglobin, casein or albumin were susceptible to hydrolysis by the membraneous protease. Partial purification of the enzyme was accomplished through disc-gel electrophoresis on polyacrylamide in the presence of 0.25% positively charged detergents like cetyltrimethylammonium bromide. An alkaline protease (pH 7.4) with properties similar to those of the erythrocyte enzyme was found in leucocytes. The similarity between the properties of the leucocytic and erythrocytic proteases and the correlation of the activity in erythrocyte membranes with content of white cells in these preparations, suggest that enzymatic activities in the contaminating leucocytes are responsible for the activity of membraneous proteases in erythrocytes.
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PMID:Membrane-bound enzymes. III. Protease activity in leucocytes in relation to erythrocyte membranes. 0 92

Porcine and ovine 19-S thyroglobulins prepared from frozen glands in several buffers using slice extraction or homogenization, ammonium sulfate precipitation and DEAE-cellulose chromatography or Sepharose 6B gel filtration were contaminated with protease activity of pH optima 4.5 and 8.6, as shown by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Optimum temperatures of autodigestion were 37 degrees C at pH 4.5 and 25 degrees C at pH 8.6. Thyroglobulins prepared from unfrozen glands pH 7.2 in 0.1 M sodium phosphate using slice extraction, ammonium sulfate precipitation and Sepharose 6B gel filtration were devoid of acid proteolytic activity but still underwent autodigestion at pH 8.6. Diisopropylfluorophosphate was a potent inhibitor of the alkaline protease activity of ovine thyroglobulin preparations. In contrast to thyroglobulin obtained from frozen glands the proteins purified from fresh unfrozen glands at pH 7.2 only showed the 19-S and the 12-S species by electrophoresis in sodium dodecyl sulfate polyacrylamide gels. Very few bands migrating faster than 12-S were visible. After full reduction and S-alkylation of porcine and ovine thyroglobulins, no qualitative changes were observed in the gel electrophoresis pattern as compared to the unmodified proteins. Species of apparent mol. wt. corresponding to the native 12 S were the major component, strongly suggesting a mol. wt. of about 330 000 for the elementary peptide chains of pig and sheep thyroglobulins.
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PMID:Endogenous proteolytic activity and constituent polypeptide chains of sheep and pig 19 S thyroglobulin. 0 35

1. The inhibitory activity of an alkaline protease inhibitor, (Streptomyces subtilisin inhibitor) towards subtilisin is found to decrease by photooxidation sensitized by methylene blue with a clear pH dependence, the midpoint of which is about 6.0. 2. Amino acid analyses of photooxidized Streptomyces subtilisin inhibitor indicate that one of the two histidyl residues and the three methionyl residues are destroyed, concomittant with the loss of inhibitory activity. 3. In accordance with this observation, one of the clearly resolved nuclear magnetic resonances from C2-protons of the two histidyl residues is selectively diminished. This histidyl residue, sensitive to photooxidation and giving a proton magnetic resonance peak at lower field, is assigned to His-106 from peptide analyses. 4. Independent modification of methionyl residues by a reaction with H2O2 or Cl2 also decreases the inhibitory activity of Streptomyces subtilisin inhibitor. 5. Modification of lysyl, tyrosyl and tryptophanyl residues by diazonium-1-H-tetrazole does not lead to the loss of the inhibitory activity. 6. The above results indicate that one or more methionyl residue(s) are essential to the inhibitory activity of Streptomyces subtilisin inhibitor, whereas lysyl, tyrosyl and tryptophanyl residues are not essential to the inhibitory activity. Modification of His-106 is also strongly related to the loss of activity, although its distinct participation in the inactivation mechanism has not been demonstrated.
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PMID:Inactivation of Streptomyces subtilisin inhibitory by chemical modifications. 1 22

Two phases were established in the synthesis of extracellular proteases by Bacillus mesentericus 73. When the growth rate was high, the synthesis of proteases was small. The maximum rate of the enzyme synthesis was observed when the growth decelerated and the production of spores started. The synthesis of alkaline protease and the formation of spores are susceptible to nitrogen-metabolite and catabolite repression. The ability to produce spores was not found in the S variant of Bacillus mesentericus that did not synthesize extracellular proteases.
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PMID:[Relationship between spore formation and synthesis of extracellular protheases in Bacillus mesentericus]. 2 85

High activity alkaline protease was obtained when the enzyme was immobilized on Dowex MWA-1 (mesh 20-50) with 10% glutaraldehyde in chilled phosphate buffer (M/15, PH 6.5). Activity yields of the protease and rennet were 27 and 29, respectively. The highest activities appeared at 60 degrees C, pH 10 for alkaline protease and 50 degrees C, pH 4.0 for rennet. The properties of both proteases were not essentially changed by the immobilization except that the Km values of both enzymes were increased about tenfold as a result of immobilization. Both proteases in the immobilized state were more stable than those in the free state at 60 degrees C. Other peptide hydrolases, beta-galactosidase, invertase, and glucoamylase, were successfully immobilized with high activities, but lipase, hexokinase, glucose-6-phosphate dehydrogenase, and xanthine oxidase became inactive.
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PMID:Preparation and properties of proteases immobilized on anion exchange resin with glutaraldehyde. 2 75

An alkaline protease was found to be associated with the granulosis virus of the Indian meal moth. Plodia interpunctella. The protease was located within the protein matrix of the occluded virus and hydrolyzed the major constituent of this matrix, a 28,000-dalton protein (granulin), to a mixture of polypeptides ranging in molecular weight from 10,000 to 27,000. A rapid, sensitive assay for the protease was developed using radioactively labeled granulosis virus as substrate. With this assay, the proteolytic activity could be detected by measuring the release of acid-soluble peptides from the labeled virus. The protease had a pH optimum of 10.5 and a temperature optimum of 40 degrees C and was inhibited by diisopropyl phosphorofluoridate, phenylmethylsulfonyl fluoride, and L-(1-tosylamido-2-phenyl) ethyl chloromethyl ketone. Purification of the protease from matrix protein was achieved by anion-exchange and gel permeation chromatography. The molecular weight of the isolated protease, determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, was approximately 14,000.
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PMID:Characterization of an alkaline protease associated with a granulosis virus of Plodia interpunctella. 2 45

The properties of the homogeneous exoprotease preparation from Bacillus subtilis varamyloliquefaciens 759 possessing the coagulase activity were studied. The enzyme is an alkaline protease, has the isopoint at pH 7.8, and not only clots blood plasmo but also hydrolyses such protein substrates as casein, hemoglobin, fibrinogen and fibrin. The enzyme is relatively stable at pH 6.0--9.0. Bivalent metal ions have virtually no effect on the enzyme activity though some of them stabilize it. The inhibitors PCMB and EDTA do not affect the activity of the enzyme whereas diisopropylfluorophosphate completely inactivates it. Fibrinogen is clotted by the enzyme only in the presence of blood plasma factors.
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PMID:[Exoprotease properties of Bacillus subtilis var. amyloliquefaciens capable of coagulating blood plasma]. 3 Aug 84

The mechanism of biologic response from exposure to a 12% subtilisin Carlsberg preparation is shown to be one of histamine release in the guinea pig. Three groups of guinea pigs were pretreated by intradermal injections withsaline solution of (1) the commercial proteolytic enzyme preparation containing 12% subtilisin Carlsberg, (2) an alkaline protease preparation obtain from Aspergillus oryzae that was isolated from cotton dust, or (3) a nonproteolytic mixture of proteins and lipases obtained from cotton seeds. The histamine content of the ling, liver, and ear tissues of guinea pigs that were pretreated with any one of the three preparations showed an in untreated animals. Following challenge by intratracheal injection of a saline solution containing the subtilisin preparation, the guinea pigs pretreated with the same preparation showed a markedly reduced liver histamine level. Challenge by inhalation exposure to the subtilisin preparation of guinea pigs that were pretreated with any one of the above preparations resulted in a lower histamine concentration in the lungs and livers.
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PMID:Histamine induction and release following proteolytic enzyme exposure. 4 32

The effect of human skin proteases on vascular permeability and leukocyte emigration in rabbit skin was investigated. The alkaline protease of human skin capable of hydrolysing trypsin substrate effectively increased vascular permeability. This effect was not inhibited by antihistamine, but almost totally so by Trasylol. The reaction was protracted. Leukocyte emigration in skin, primarily of PMN-cells at 12 hrs, and later a migration of mononuclear cells, also resulted. Swelling of the dermal fibres was noted. The alkaline protease of human skin capable of hydrolysing chymotrypsin substrate also increased vascular permeability, but this phenomenon was effectively inhibited by antihistamine and the reaction was of brief duration. The leukocyte emigration caused by this enzyme was remarkable. The acid proteases of human skin resembling cathepsin B1 and D also caused brief increased vascular permeability, which was effectively inhibited by antihistamine. The cellular reactions to these acid proteases were mild. The role of protease inhibitors in skin in the enzyme reactions is discussed.
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PMID:Human skin proteases: effect of separated proteases on vascular permeability and leukocyte emigration in skin. 7 4

The use of acid cheese whey as an essential substrate for the production of alkaline protease was studied by growing Bacillus subtilis NRRL 3411 on different conditions of aereation. The maximum enzymatic activity of 17 000 proteolytic units was obtained in the following conditions: 200 RPM, air flow of 1 v/v minutes (KLa 37 h-1), separate sterilization of the medium components and periodical additions of peptone.
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PMID:[Production of alkaline protease from acid cheese whey]. 9 9


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