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Active site mutagenesis and phospholipid hydroperoxide reductase activity of poplar type II peroxiredoxin
Author(s) -
Rouhier Nicolas,
Gelhaye Eric,
Corbier Catherine,
Jacquot Jean Pierre
Publication year - 2004
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.0031-9317.2004.0203.x
Subject(s) - cumene hydroperoxide , peroxiredoxin , biochemistry , mutagenesis , active site , mutant , hydrogen peroxide , site directed mutagenesis , cysteine , enzyme , glutaredoxin , chemistry , phospholipid , peroxidase , glutathione , catalysis , membrane , gene
The nature of the active site and the substrate specificity of poplar type II peroxiredoxin, an enzyme which preferentially uses glutaredoxin as an electron donor, were investigated in this study. The type II peroxiredoxin is able to use phospholipid hydroperoxide nearly as efficiently as hydrogen peroxide. Two of the hyper‐conserved amino acid residues in peroxiredoxins have been altered, by site‐directed mutagenesis, generating the mutants T48V and R129Q. The two mutant proteins are inactive with hydrogen peroxide or tertiary butyl hydroperoxide as substrates. On the other hand, the mutant enzymes catalyse the degradation of cumene hydroperoxide with low efficiency. This suggests that the thiol‐dependent regeneration process of the catalytic cysteine is not affected by the mutations and that all substrates are not accommodated identically in the active site.