Open AccessThioredoxin Ch1 of Chlamydomonas reinhardtii displays an unusual resistance toward one‐electron oxidation
Author(s) -
SicardRoselli Cécile,
Lemaire Stéphane,
Jacquot JeanPierre,
Favaudon Vincent,
Marchand Christophe,
HouéeLevin Chantal
Publication year - 2004
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.2004.04279.x
Subject(s) - oxidizing agent , chlamydomonas reinhardtii , radical , radiolysis , thioredoxin , ferredoxin thioredoxin reductase , electron transfer , chemistry , azide , photochemistry , intramolecular force , electron transport chain , thioredoxin reductase , reactive oxygen species , redox , biochemistry , mutant , enzyme , stereochemistry , inorganic chemistry , organic chemistry , gene
To test thioredoxin resistance to oxidizing free radicals, we have studied the one‐electron oxidation of wild‐type thioredoxin and of two forms with the point mutations D30A and W35A, using azide radicals generated by γ‐ray or pulse radiolysis. The oxidation patterns of wild‐type thioredoxin and D30A are similar. In these forms, Trp35 is the primary target and is ‘repaired’ by one‐electron reduction; first by intramolecular electron transfer from tyrosine, and then from other residues. Conversely, during oxidation of W35A, Trp13 is poorly reactive. For all proteins, activity is conserved showing an unusual resistance toward oxidation.