Irreversible reaction of 3-amino-1:2:4-triazole and related inhibitors with the protein of catalase

Margoliash, E.; Novogrodsky, Abraham; Schejter, Abel

doi:10.1042/bj0740339

Cited by 483 publications

(211 citation statements)

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“…The concentrations and effects of these inhibitors have been reported in earlier investigations (Margoliash et al, 1960;Buckley et al, 1991;Kinnula et al, 1992aKinnula et al, , 1998. These concentrations are not toxic, and they have caused at least 85% inhibition of catalase and depletion of glutathione in these same cells (Kinnula et al, 1992a).…”

Section: Pre-treatment With Aminotriazole or Buthionine Sulfoximinementioning

confidence: 82%

Generation of reactive oxygen species by human mesothelioma cells

et al. 1999

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Malignant mesothelioma cells contain elevated levels of manganese superoxide dismutase (MnSOD) and are highly resistant to oxidants compared to non-malignant mesothelial cells. Since the level of cellular free radicals may be important for cell survival, we hypothesized that the increase of MnSOD in the mitochondria of mesothelioma cells may alter the free radical levels of these organelles. First, MnSOD activity was compared to the activities of two constitutive mitochondrial enzymes; MnSOD activity was 20 times higher in the mesothelioma cells than in the mesothelial cells, whereas the activities of citrate synthase and cytochrome c oxidase did not differ significantly in the two cell lines. This indicates that the activity of MnSOD per mitochondrion was increased in the mesothelioma cells. Superoxide production was assayed in the isolated mitochondria of these cells using lucigenin chemiluminescence. Mitochondrial superoxide levels were significantly lower (72%) in the mesothelioma cells compared to the mesothelial cells. Oxidant production in intact cells, assayed by fluorimetry using 2′,7′-dichlorodihydrofluorescein as a fluorescent probe, did not differ significantly between these cells. We conclude that mitochondrial superoxide levels are lower in mesothelioma cells compared to nonmalignant mesothelial cells, and that this difference may be explained by higher MnSOD activity in the mitochondria of these cells. Oxidant production was not different in these cells, which may be due to the previously observed increase in H 2 O 2 -scavenging mechanisms of mesothelioma cells. © 1999 Cancer Research Campaign

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Section: Pre-treatment With Aminotriazole or Buthionine Sulfoximinementioning

confidence: 82%

Generation of reactive oxygen species by human mesothelioma cells

et al. 1999

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“…The enzymes are active within a broad pH range, resistant to treatment with ethanol and specifically inhibited by 3-amino-1,2,4-triazole (Nadler et al, 1986;Margoliash et al, 1960). Bifunctional catalase-peroxidases constitute a distinct group of proteins exhibiting catalase and peroxidase activities.…”

Section: Introductionmentioning

confidence: 99%

The mycelium-associated Streptomyces reticuli catalase-peroxidase, its gene and regulation by FurS

Zou¹,

Borovok²,

Lucana³

et al. 1999

Microbiology

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During early stages of growth, Streptomyces reticuli synthesizes a hyphaeassociated, haem-containing enzyme which exhibits catalase and peroxidase activities with broad substrate specificity (CpeB). The purified dimeric enzyme (160 kDa) consists of two identical subunits. Using anti-CpeB antibodies and an expression-as well as a mini-library, the corresponding cpeB gene was identified and sequenced. It encodes a protein of 740 aa with a molecular mass of 81.3 kDa. The deduced protein shares the highest level of amino acid identity with KatG from Caulobacter crescentus and Mycobacterium tuberculosis, and PerA from Bacillus stearothermophilus. Streptomyces lividans transformants carrying cpeB and the upstream-located furs gene with its regulatory region on the bifunctional vector pWHM3 produced low or enhanced levels of CpeB in the presence or absence of Fe ions, respectively. An in-frame deletion of the major part of furs induces increased CpeB synthesis. The data imply that Furs regulates the transcription of cpeB. The deduced Furs protein is rich in histidine residues, contains a putative N-terminally situated helix-turn-helix motif and has a molecular mass of 15.1 kDa. It shares only 29% amino acid identity with the Escherichia coli ferric uptake regulator (Fur) protein, but about 64% with FurA deduced from the genomic sequences of several mycobacteria. The predicted secondary structures of Furs and FurA are highly similar and considerably divergent from those of the E. coli Fur. In contrast to some Gram-negative bacteria, within several mycobacteria an intact furA gene or a furA pseudogene is upstream of a catalase-peroxidase (katG) gene predicted to encode a functional or a non-functional (Mycobacterium leprae) enzyme. Thus the data obtained for Streptomyces reticuli are expected to serve as an additional model to elucidate the regulation of mycobacterial catalase-peroxidase genes.1

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“…This inhibitor only binds to compound I and not to free catalase [6]. Further to this, the source of hydrogen peroxide was studied by administration of inhibitors of several peroxide producing oxidases.…”

Section: Introductionmentioning

confidence: 99%