Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 273 (24), 5589-97

Hydroperoxide Reduction by Thioredoxin-Specific Glutathione Peroxidase Isoenzymes of Arabidopsis Thaliana

Affiliations

Hydroperoxide Reduction by Thioredoxin-Specific Glutathione Peroxidase Isoenzymes of Arabidopsis Thaliana

Aqib Iqbal et al. FEBS J.

Abstract

Arabidopsis thaliana contains eight glutathione peroxidase (GPX) homologs (AtGPX1-8). Four mature GPX isoenzymes with different subcellular distributions, AtGPX1, -2, -5 and -6, were overexpressed in Escherichia coli and characterized. Interestingly, these recombinant proteins were able to reduce H2O2, cumene hydroperoxide, phosphatidylcholine and linoleic acid hydroperoxides using thioredoxin but not glutathione or NADPH as an electron donor. The reduction activities of the recombinant proteins with H2O2 were 2-7 times higher than those with cumene hydroperoxide. Km values for thioredoxin and H2O2 were 2.2-4.0 and 14.0-25.4 microM, respectively. These finding suggest that GPX isoenzymes may function to detoxify H2O2 and organic hydroperoxides using thioredoxin in vivo and may also be involved in regulation of the cellular redox homeostasis by maintaining the thiol/disulfide or NADPH/NADP balance.

Similar articles

See all similar articles

Cited by 22 PubMed Central articles

See all "Cited by" articles

Publication types

MeSH terms

LinkOut - more resources

Feedback