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: EC:1.11.1.6 (catalase)
55,569 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1) Catalase from green leaves of Lens culinaris (lentils) was investigated with respect to isoenzyme patterns. In contrast to other plants, which have been reported to contain multiple forms of catalase, only one form of this enzyme was revealed when crude extracts were subjected to starch gel electrophoresis or to polyacrylamide disc-gel electrophoresis. Furthermore, catalases from leaves, stems and cotyledons were electrophoretically identical. 2) The leaf enzyme has been purified by conventional methods to apparent homogeneity. It has a molecular weight of 225 000 (ultracentrifuge) and is composed of four identical subunits of molecular weight 54 000 (sodium dodecylsulphate gel electrophoresis). The ratio A280/A405 of the pure enzyme was found to be 1.5. The isoelectric point is at pH 5.5. The enzyme, very labile at pH-values below 7.0, is stable in Tris chloride and potassium phosphate buffers between pH 7.5 and 9.5. It is slowly inactivated by 1mM dithiothreitol and is rapidly inactivated by 1mM mercaptoethanol. 3) The catalase was shown to be the major protein component of the peroxisomal matrix. It could not be detected at the membranes of the leaf peroxisomes.
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PMID:Plant microbody proteins, I. Purification and characterization of catalase from leaves of lens culinaris. 0 64

The distribution of catalase and D-amino acid oxidase, marker enzymes for peroxisomes, was determined cytochemically in the kidney tubules of an euryhaline teleost, the three-spined stickleback. Catalase activity was localized with the diaminobenzidine technique. The presence of D-amino acid oxidase was determined using H2O2 generated by the enzyme, D-alanine as a substrate, and cerous ions for the formation of an electron-dense precipitate. Both enzymes appeared to be located in microbodies. The combined presence of these enzymes characterizes the microbodies as peroxisomes. Biochemically and cytochemically, no urate oxidase or glycolate-oxidizing L-alpha-hydroxy acid oxidase could be demonstrated. Stereological analysis of the epithelia lining the renal tubules showed that the fractional volume of the microbodies is 5 to 10 times higher in the cells of the second proximal tubules than in the other nephronic segments or the ureter. The fractional volume of the microbodies was similar in kidneys of freshwater and seawater fishes.
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PMID:The cytochemical demonstration of catalase and D-amino acid oxidase in the microbodies of teleost kidney cells. 1 91

Methoxypolyethylene glycols of 1900 daltons (PEG-1900) or 5000 daltons (PEG-5000) were covalently attached to bovine liver catalase using 2,4,6-trichloro-s-triazine as the coupling agent. Rabbits were immunized by the intravenous and intramuscular routes with catalase modified by covalent attachment of PEG-1900 to 43% of the amino groups (PEG-1900-catalase). The intravenous antiserum did not yield detectable antibodies against PEG-1900-catalase or native catalase, as determined by Ouchterlony and complement fixation methods, whereas the intramuscular antiserum contained antibodies to both PEG-1900-catalase and catalase. PEG-1900 did not react with either antiserum. Catalase was prepared in which PEG-5000 was attached to 40% of the amino groups (PEG-5000-catalase). This catalase preparation did not react with either antiserum. PEG-1900-catalase retained 93% of its enzymatic activity; PEG-5000-catalase retained 95%. PEG-5000-catalase resisted digestion by trypsin, chymotrypsin, and a protease from Streptomyces griseus. PEG-1900-catalase and PEG-5000-catalase exhibited enhanced circulating lives in the blood of acatalasemic mice during repetitive intravenous injections. No evidence was seen of an immune response to injections of the modified enzymes. Mice injected repetitively with PEG-5000-catalase remained immune competent for unmodieied catalase, and no evidence of tissue or organ damage was seen.
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PMID:Effect of covalent attachment of polyethylene glycol on immunogenicity and circulating life of bovine liver catalase. 1 7

The paper confirms the existence of a peroxide mechanism involved in oxidation of iron and manganeses by the most typical iron bacteria growing at neutral acidity of the medium. Oxidation of bivalent iron and manganese is accomplished by the simultaneous action of catalase and hydrogen peroxide produced in the respiratory chain in the course of oxidation of organic substances. Catalase performs the peroxidase function in these processes. The possibility of these biological reactions to occur and the necessary conditions have been studied in vitro. Possible variants of iron and manganese oxidation by iron bacteria are discussed, including the conditions for "symbiotic" oxidation of manganese by mixed cultures of microorganisms.
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PMID:[Mechanism of the oxidation of divalent iron and manganese by iron bacteria developing in a neutral acidic medium]. 3 22

Paraquat, a herbicide which is known to increase intracellular levels of superoxide anion (O2-), stimulated guanylate cyclase [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2.] activity. This stimulation by paraquat was seen at concentrations as low as 0.005 mM. The activation of guanylate cyclase by paraquat was not blocked by KCN, an inhibitor of superoxide dismutase [EC 1.15.1.1.], suggesting that the activation process probably does not involve superoxide dismutase which converts superoxide anion to hydrogen peroxide and ultimately to hydroxyl radical. Catalase [EC 1.11.1.6.] did not block the paraquat activation of guanylate cyclase indicating that hydrogen peroxide was probably not involved in the activation process. Butylated hydroxytoluene, a hydroxyl radical scavenger, also had no effect on the paraquat activation of guanylate cyclase activity. Superoxide dismutase inhibited the paraquat activation of guanylate cyclase. Thus, it would appear that superoxide ion itself can activate guanylate cyclase circumventing any requirement for hydroxyl radical formation.
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PMID:Activation of liver guanylate cyclase by paraquat: possible role of superoxide anion. 3 15

Catalase (E.C. 1.11.1.6) activity and NADPH-dependent lipid peroxidation have been measured in liver microsomes from normal and acatalasemic mice. The absence of lipid peroxidation in acatalatic microsomes is not restituted by exogenous catalase as is microsomal methanol oxidation nor is it inhibited by sodium azide, thus suggesting an additional abnormality in these mice.
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PMID:Absence of microsomal lipid peroxidation in acatalasemic mice. 3 20

The activities of peroxisomal enzymes of rat liver were followed 1 to 10 days after subtotal (60-70%) hepatectomy in homogenates prepared from regenerating livers and in cell fractions isolated from them. Catalase activity was found to be depressed in the total liver homogenate (H) as well as in the mitochondrial (M) and soluble (S) fractions, while it did not change appreciably in the microsomal (Mc) and lysosomal (L) fractions. Alpha-hydroxyacid oxidase behaved in a similar fashion. In contrast to these enzymes, urate oxidase activity remained unchanged in H, whereas it was decreased in M and increased in L and Mc during the first 5 days after operation. These results agree well with the assumption that microbody proliferation is initiated by the fragmentation of large peroxisomes. The different relations of peroxisomal enzyme activities during regeneration time are discussed with respect to the possible existence of various kinds of peroxisomes with different enzyme equipments and with different turnover rates. Biochemical examinations ions were paralleled to morphological and histochemical studies. An early increase in number of peroxisomes was found to occur during the first day after partial hepatectomy, which is accompanied by decrease in particle size. During the first mitotic wave (24-36 hrs post op.) the number of peroxisomes per cell was reduced to about the half. After this time number and size of the particles began to increase. Positive staining of ribosomes was frequently observed in the vicinity of peroxisomes after the application of the cytochemical catalase reaction (alkaline diaminobenzidine medium). This phenomenon is interpreted to represent rather a diffusion artifact than the cytochemical identification of newly synthesized catalase.
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PMID:Influence of subtotal hepatectomy on peroxisomes and peroxisomal enzymes of rat liver and isolated liver cell fractions. 5 39

The unstable catalase variant found in the blood of individuals homozygous for Swiss-type acatalasemia and the enzyme species present in heterozygous carriers of this rare defect have been further characterized. The mutant enzyme isolated from acatalasemic red cells is considerably more heat labile and differs in electrophoretic mobility from the normal enzyme. Catalase preparations obtained from heterozygotes consist of an apparently uniform enzyme species, probably representing a molecular hybrid, with properties intermediate to those of the normal and the variant enzyme. However, antigenic identity of catalase from all three sources is observed. Model experiments indicate that hybrid catalase molecules can be produced by recombining normal and variant dimer subunits. Fractionation of erythrocytes according to density and age shows that most of the residual catalase activity is localized in juvenile acatalasemic cells, whereas in normal and heterozygous individuals the catalase activity level does not alter significantly during the life span of the red cells. These findings agree with the observation that there is no gene dosage in heterozygotes, their catalase activity values falling within the normal range.
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PMID:Properties of erythrocyte catalase from homozygotes and heterozygotes for Swiss-type acatalasemia. 6 44

Glucose uptake by whole-cell suspensions of the obligate anaerobe Bacteroides thetaiotaomicron was two- to fourfold higher under aerobic conditions than during incubation under atmospheres of N(2) or H(2) gas. The O(2)-stimulated uptake activity was lost rapidly (>70% in 5 h) when cell suspensions were incubated aerobically, but this loss was prevented by the addition of crude catalase. Catalase had no apparent effect on cell viability during these incubations. Glucose uptake activity was strongly inhibited by a 10-fold excess of mannose or galactose but not by methyl-alpha-d-glucoside, fructose, or lactose. Both glucose and mannose were rapidly incorporated into polyglucose after uptake. The O(2)-stimulated glucose uptake was not inhibited by cyanide, azide, 2,4-dinitrophenol, or 2-N-heptyl-4-hydroxyquinoline-N-oxide. However, p-chloromercuribenzoate, menadione, and sodium fluoride inhibited uptake by 88, 67, and 55%, respectively. All attempts to detect phosphoenolpyruvate-phosphotransferase activity for glucose, methyl-alpha-d-glucoside, and 2-deoxyglucose were negative. The bacteria contained hexokinase activity and a complete glycolytic Embden-Meyerhof pathway.
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PMID:Uptake and incorporation of glucose and mannose by whole cells of Bacteroides thetaiotaomicron. 7 63

1. Superoxide dismutase activity was present in the heterocysts and vegetative cells of Anabaena cylindrica, but was always lower in the heterocysts. 2. No qualitative differences were found in the superoxide dismutase from the two cellular types. 3. Catalase activity was also present in both cellular types. 4. Most of the NADP reductase activity, as assayed with menadione or ferredoxin as electron acceptor, was localized within the heterocysts. 5. Studies on H2 consumption showed that most of the hydrogenase activity was associated with the heterocysts. 6. The results are discussed in terms of the postulate that superoxide dismutase and catalase are involved in the protection of the proton-donating systems participating in N2 fixation and H2 metabolism of heterocysts.
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PMID:Superoxide dismutase and catalase in the protection of the proton-donating systems of nitrogen fixation in the blue-green alga Anabaena cylindrica. 10 Dec 10


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