Biochemical characterization of glutaredoxins from Chlamydomonas reinhardtii: kinetics and specificity in deglutathionylation reactions.
Protein deglutathionylation is mainly catalyzed by glutaredoxins (GRXs). We have analyzed the biochemical properties of four of the six different GRXs of Chlamydomonas reinhardtii. Kinetic parameters were determined for disulfide and dehydroascorbate reduction but also for deglutathionylation of artificial and protein substrates. The results indicate that GRXs exhibit striking differences in their catalytic properties, mainly linked to the class of GRX considered but also to the pK(a) of the N-terminal catalytic cysteine. Furthermore, glutathionylated proteins were found to exhibit distinct reactivities with GRXs. These results suggest that glutathionylation may allow a fine tuning of cell metabolism under stress conditions.
Gao
Xing-Huang
XH
Institut de Biologie des Plantes, UMR 8618, CNRS/Université Paris-Sud, Orsay, France.
Zaffagnini
Mirko
M
Bedhomme
Mariette
M
Michelet
Laure
L
Cassier-Chauvat
Corinne
C
Decottignies
Paulette
P
Lemaire
Stéphane D
SD
D002384:Catalysis; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism*; D004220:Disulfides / Q000378:metabolism*; D054477:Glutaredoxins / Q000378:metabolism*; D007700:Kinetics; D012680:Sensitivity and Specificity
D004220:Disulfides; D054477:Glutaredoxins; D003545:Cysteine