Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This paper describes spontaneous post-mortem changes of peroxisomal staining in normal liver and kidney of rats and in human autopsy liver. At room temperature, regional staining loss is observed at 18 h after death in rat kidney, at 24 h in human liver and at 48 h in rat liver. Preservation at 4 degrees C delays this phenomenon. In human liver, the peroxisomal volume density is decreased at both temperatures at 48 h. After freezing of fresh tissue in dry ice, peroxisomal staining is decreased homogeneously. Under the electron microscope, peroxisomal alterations suggest a loss of catalase activity. These changes do not necessarily preclude the study of peroxisomal features since, even after 48 h at room temperature, peroxisomes are still well stained in the less affected regions. Catalase and three beta-oxidation enzymes, namely acyl-CoA oxidase, bifunctional protein (with enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase) and 3-oxoacyl-CoA thiolase, could be visualized immunocytochemically in human autopsy livers up to 48 h after death. However, the study of certain peroxisomal features such a catalase activity and peroxisomal distribution, may be hampered as the post-mortem period is prolonged.
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PMID:Post-mortem visualization of peroxisomes in rat and in human liver. 169 Jan 88

The absence of peroxisomes in patients with the cerebro-hepato-renal (Zellweger) syndrome is accompanied by a number of biochemical abnormalities, including an accumulation of very long-chain fatty acids. We show by immunoblotting that there is a marked deficiency in livers from patients with the Zellweger syndrome of the peroxisomal beta-oxidation enzyme proteins acyl-CoA oxidase, the bifunctional protein with enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase activities and 3-oxoacyl-CoA thiolase. Using anti-(acyl-CoA oxidase), increased amounts of cross-reactive material of low Mr were seen in the patients. With anti-(oxoacyl-CoA thiolase), high Mr cross-reactive material, presumably representing precursor forms of 3-oxoacyl-CoA thiolase, was detected in the patients. Catalase protein was not deficient, in accordance with the finding that catalase activity is not diminished in the patients. Thus in contrast to the situation with catalase functional peroxisomes are required for the stability and normal activity of peroxisomal beta-oxidation enzymes.
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PMID:Peroxisomal beta-oxidation enzyme proteins in the Zellweger syndrome. 397 16

Human (HepG2) and rat (MH1C1) hepatoblastoma cells were incubated with different concentrations of the hypolipidaemics cetaben, clofibrate and thyroxine. The enzymatic activities of catalase, peroxisomal bifunctional enzyme, succinate dehydrogenase, and 3-oxoacyl-CoA thiolase were measured. In order to determine the point of regulation of the enzymatic activities Northern and Slot blot experiments with probes for peroxisomal bifunctional enzyme, catalase and fatty acyl CoA oxidase were performed on total RNA. Catalase activity was enhanced in HepG2 cells treated with 3 mmol/l clofibric acid to 135% of control and the mRNA value to 2.6 fold, whereas in cetaben treated cells the enhancement (up to 119% of control) was less pronounced. In MH1C1 cells catalase activity was not changed by any of the drugs. The activity of the peroxisomal bifunctional enzyme was not affected in HepG2 cells by clofibric acid and cetaben, whereas the mRNA level was elevated to 2.3 fold by 10 micromol/l cetaben. At high concentrations of cetaben all enzyme activities were decreased in both cell lines due to its high cytotoxicity. Our data show that, due to the differences in the genomic organisation, the regulation of the enzyme activities is different in human and rat, but the results from the human and rat hepatoblastoma cells correlate with the findings in whole man and rat, so that a human in vitro system is more suitable for pharmacological tests. These results suggest that the human hepatoma cell line HepG2 may be a useful model system for studies of the influence of hypolipidaemics on the peroxisomal enzyme system.
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PMID:Differential induction of peroxisomal enzymes by hypolipidaemics in human (HepG2) and rat (MH1C1) hepatoma cell lines. 862 53

We established a Chinese hamster ovary cell line having a temperature-sensitive phenotype in peroxisome biogenesis. This mutant (65TS) was produced by transforming a PEX2-defective mutant, Z65, with a mutant PEX2 gene, PEX2(E55K), derived from a patient with infantile Refsum disease, a milder form of peroxisome biogenesis disorder. In 65TS, catalase was found in the cytosol at a nonpermissive temperature (39 degrees C), but upon the shift to a permissive temperature (33 degrees C), catalase gradually localized to the structures containing a 70-kDa peroxisomal membrane protein, PMP70. In contrast to catalase, other matrix proteins containing typical peroxisome targeting signals, acyl-CoA oxidase and peroxisomal 3-ketoacyl-CoA thiolase, were co-localized with PMP70 in most cells, even at 39 degrees C. We found that these structures are partially functional peroxisomes and named them "catalase-less peroxisomes." Catalase-less peroxisomes were also observed in human fibroblasts from patients with milder forms of peroxisome biogenesis disorder, including the one from which the mutant PEX2 gene was derived. We suggest that these structures are the causes of the milder phenotypes of the patients. Temperature-dependent restoration of the peroxisomes in 65TS occurred even in the presence of cycloheximide, a protein synthesis inhibitor. Thus, we conclude that in 65TS, catalase-less peroxisomes are the direct precursors of peroxisomes.
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PMID:Catalase-less peroxisomes. Implication in the milder forms of peroxisome biogenesis disorder. 1096 Apr 80