Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.32 (bromelain)
 1,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Stem bromelain that had been irreversibly inhibited with 1,3-dibromo[2-(14)C]-acetone was reduced with sodium borohydride and carboxymethylated with iodoacetic acid. After digestion with trypsin and alpha-chymotrypsin three radioactive peptides were isolated chromatographically. The amino acid sequences around the cross-linked cysteine and histidine residues were determined and showed a high degree of homology with those around the active-site cysteine and histidine residues of papain and ficin.
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PMID:The amino acid sequence around the active-site cysteine and histidine residues of stem bromelain. 542 46

Roles of kininogens in the development of potentiation of carrageenan edema in rats by angiotensin converting enzyme (ACE, = kininase II) inhibitor were studied. Carrageenan-induced edema was potentiated by oral administration of YS980, an ACE inhibitor, at a dose of 1 mg/kg 0.5 h before carrageenan injection. Intravenous injection of bromelain, a kininogen (KGN) depletor, at 3 mg/kg produced reduction of plasma KGN (total and high molecular weight KGN), which resulted in suppression of carrageenan edema and suppression of edema potentiation induced by YS980. Even after the plasma KGN level and inflammatory response to carrageenan returned to normal 24 h after the administration of bromelain, the potentiative effect of YS980 on the carrageenan edema remained suppressed. Thus, some factor other than plasma KGN is thought to be involved in the potentiation mechanisms on the carrageenan edema by YS980. Partially purified KGN from rat plasma (0.1 mg/site: liberated 4.4 X 10(-8) g bradykinin eq by trypsin digestion) completely restored the suppressed potentiation to normal by local preinjection to the inflamed site. In addition, such restoration was not observed in the animal in which plasma KGN was reduced 3 h after administration of bromelain. These results suggest that KGN, not only in plasma but also in tissue, play an active role in the development of potentiation of carrageenan edema by ACE inhibitor.
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PMID:Potentiative effect of angiotensin converting enzyme inhibitor on carrageenan edema in rats and the role of tissue kininogen. 609 Jun 35

An endogenous inhibitor of calcium-activated neutral protease (CANP), which was isolated from rabbit skeletal muscle under mild conditions, comprised high- and low-molecular-weight components. The latter (LMW-inhibitor; Mr=50,000) was purified to homogeneity by means of chromatography on DEAE-cellulose and phenyl-Sepharose CL-4B and chromatofocusing. The purified inhibitor is a protein composed of two polypeptide chains with molecular weights of 26,000 and 24,000 daltons. It contains large amounts of glutamic acid, alanine, and serine, and small amounts of aromatic amino acids. It was specific for CANPs having low (m-type) and high (mu-type) Ca2+-sensitivity, had no effect on any other protease examined (trypsin, alpha-chymotrypsin, bromelain, ficin, papain, thermolysin, etc.), and inhibited rabbit mCANP more effectively than rabbit muCANP or chicken mCANP. It was demonstrated that the inhibition is due to the formation of a stoichiometric complex between two molecules of rabbit mCANP and one inhibitor molecule.
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PMID:Purification and characterization of an inhibitor of calcium-activated neutral protease from rabbit skeletal muscle: purification of 50,000-dalton inhibitor. 609 76

The sensitivity of highly purified human fibroblast interferon and partially purified human leukocyte interferon to several proteolytic and glycolytic enzymes was determined with respect to antiviral activity, isoelectric point, molecular weight, and thermal stability. Leucine aminopeptidase altered the distribution of isoelectric points for both interferons but produced little change in molecular weights; this enzyme somewhat reduced the activity of only leukocyte interferon. Treatment of fibroblast interferon with carboxypeptidases A and B did not greatly decrease antiviral activity, but it did slightly reduce the molecular weight of the interferon and substantially altered the distribution of isoelectric point values; similar treatment of leukocyte interferon caused some loss in activity, especially of the 17,000-molecular-weight species. Both interferons were inactivated rapidly by treatment with the endoproteases trypsin, pepsin, bromelain, and subtilisin. Chymotrypsin shifted the isoelectric points of both interferons, but only leukocyte interferon was significantly inactivated. Treatment with neuraminidase and beta-galactosidase changed the isoelectric point distribution but did not affect the activity or thermal stability of either interferon; such a treatment reduced the molecular weight of fibroblast interferon and the size heterogeneity of leukocyte interferon. Treatment with neuraminidase and then leucine aminopeptidase greatly reduced the activity of both interferons, especially leukocyte interferon. The data indicate that biologically active forms of fibroblast and leukocyte interferons can be distinguished by their relative sensitivity to certain proteases.
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PMID:Enzymatic modifications of human fibroblast and leukocyte interferons. 616 Feb 60

The papain inhibitor from human spleen was purified by extraction in isotonic sucrose, acetone fractionation, papain-Sepharose affinity chromatography and gel filtration on Sephadex G-50. The purified inhibitor was fractionated by electrofocusing into four major isoelectric variants with pI values of 4.7, 5.0, 6.0 and 6.5. These variants can be classified into two groups: the acidic type, comprising the variants with pI 4.7 and 5.0, and the neutral type, comprising the variants with pI 6.0 and 6.5. The following properties distinguish the two types: 1. Immunological properties: antibodies raised against either of the neutral variants precipitated both of these, but not the acidic variants. The antiserum against the human epidermal cysteineproteinase inhibitor precipitated the acidic variants, but not the neutral variants. 2. Molecular size: two-dimensional electrophoresis of the purified inhibitor gave molecular weights of 11400 for the acidic variants and 12000 for the neutral variants. The pI 6.0 variant contained two compounds with molecular weights of 12000 and 12800. 3. Enzyme spectrum: human cathepsin B was inhibited by the acidic type, while the neutral type was a poor inhibitor. Both types inhibited cathepsin H, papain, ficin and bromelain, although the inhibition of bromelain did not exceed 70%. Human cathepsin D, bovine trypsin and chymotrypsin and porcine elastase were not inhibited by either type.
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PMID:Human spleen cysteineproteinase inhibitor. Purification, fractionation into isoelectric variants and some properties of the variants. 618 75

A new method for removing nearly all active endoproteinases from fluids called "sandwich affinity chromatography" is described. It is based on strong chelate binding of alpha 2-macroglobulin (alpha 2M) and its proteinase complexes to Zn2+-bis-carboxymethylamino-Sepharose (Zn chelate-Sepharose) and its ability to complex most active endoproteinases. The preferred performance minimizing unspecific protein adsorption is binding first alpha 2M to Zn chelate-Sepharose and then adsorbing the proteinase to the alpha 2M-Zn chelate-Sepharose using elevated salt concentrations. A suitable standard buffer, in which most proteases and alpha 2M are active and the protease-alpha 2M complex remains bound to Zn chelate-Sepharose, is 0.02 mol/liter sodium phosphate, pH 6.5, containing 0.15 mol/liter NaCl. As an example, the reaction of trypsin with alpha 2M-Zn chelate-Sepharose was studied. After saturating Zn chelate-Sepharose first with alpha 2M and then with trypsin under standard conditions, the bound alpha 2M equals the bound trypsin activity (measured with Chromozym TRY). The specific binding capacity of alpha 2M-Zn chelate-Sepharose for proteases was determined in this way to be 30-40 U trypsin, i.e., 0.40-0.54 mg/ml of gel. The balance and the fact that the bound trypsin is inaccessible to soybean trypsin inhibitor indicate that at these conditions no unspecific trypsin binding occurs. Chymotrypsin, thermolysin, elastase, bromelain, ficin, and papain are also bound at standard conditions but not exoproteases like carboxypeptidases A and Y. Advantages of the sandwich affinity chromatography are the simple loading procedure by adsorption, the high capacity of the gel material, and the possibility to reuse the Zn chelate-Sepharose after eluting reacted alpha 2M and reloading with new alpha 2M.
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PMID:Removal of endoproteinases from biological fluids by "sandwich affinity chromatography" with alpha 2-macroglobulin bound to zinc chelate-Sepharose. 620 48

An endogenous inhibitor of calcium-activated neutral protease was purified to homogeneity from rabbit skeletal muscle using ion-exchange chromatography on DEAE-cellulose and QAE-Sephadex A-50 columns, chromatofocusing, and hydrophobic interaction chromatography on a phenyl-Sepharose CL-4B column. The purified inhibitor was shown to be a dimer of identical subunits and each subunit has a molecular weight of about 34,000. This inhibitor was remarkably thermo- and acid-stable. It was specific for calcium-activated neutral protease and had no effect on any other protease examined (trypsin, papain, alpha-chymotrypsin, bromelain, etc.). It is demonstrated that the inhibition is due to the formation of stoichiometric complex between two enzyme molecules and one inhibitor molecule.
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PMID:Purification and characterization of an inhibitor of calcium-activated neutral protease from rabbit skeletal muscle. 627 75

Treatment of lymphocytic choriomeningitis virus with proteolytic enzymes, hyaluronidase, and phospholipase C increased infectious titres. Biochemical analysis of bromelain- and trypsin-treated virus revealed that infectivity was high in spite of the decrease to low or undetectable levels of all viral glycoproteins as well as partial degradation of the nucleoprotein.
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PMID:Lymphocytic choriomeningitis virus. VII. Structural alterations of the virion by treatment with proteolytic enzymes without loss of infectivity. 637 2

Incubation of guinea pig lung mitochondrial suspension in an isotonic low ionic strength buffer containing various proteolytic enzymes caused significant stimulation of the glycerophosphate acyltransferase activity. The maximal stimulation range between 20 and 105%, and the order was as follows: bromelain greater than chymotrypsin greater than pronase greater than trypsin greater than papain greater than nagarse. Under hypotonic conditions, over 85% of GAT was destroyed by all the proteolytic enzymes. Microsomal enzyme activity was consistently inhibited (greater than 95%) by exposure to any of these proteases even under isotonic conditions. These results suggest that GAT is located on the inner aspect of the mitochondrial outer membrane. Also, it is likely that a portion of this enzyme or that of a modulator is present in the outer side of the outer membrane and proteolysis of this component causes stimulation.
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PMID:Location of glycerol phosphate acyltransferase in the transverse plane of mitochondrial outer membrane of guinea pig lung. 638 69

Attachment of [35S]methionine-labelled mammalian type 3 reovirus to murine L cells and human HeLa cells was studied under equilibrium conditions. Cellular attachment sites could be completely saturated with 35S-labelled reovirus, indicating that specific attachment sites for reovirus are present on the surface of these cells. We calculated that L cells possess about 86000-105000 attachment sites per cell while HeLa cells possess about 126000-147000 sites per cell for type 3 reovirus. Unlabelled reovirus was highly efficient in competing for attachment by 35S-labelled reovirus to the saturable attachment sites of both L and HeLa cells, further indicating the specificity of the interaction. We also found that unlabelled reovirus competed equally well for both binding and internalization of 35S-labelled reovirus into murine L cells, suggesting that the L cell attachment site may serve as a virus entry site. Phospholipase digestion of L cells had no effect on subsequent reovirus attachment, while treatment of L cells with moderate concentrations of bromelain (but not trypsin, proteinase K or pronase) and Vibrio cholerae neuraminidase reproducibly decreased subsequent reovirus attachment. These results and those of others (Epstein et al., 1984, Virology 133, 46-55) suggest that mammalian reoviruses attach to specific cell surface receptors on at least two species of mammalian cells to initiate the infectious cycle.
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PMID:Saturable attachment sites for type 3 mammalian reovirus on murine L cells and human HeLa cells. 639 64


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