title: A redox-dependent dimerization switch regulates activity and tolerance for reactive oxygen species of barley seed glutathione peroxidase.
abstract: Monomeric and dimeric forms of recombinant barley (Hordeum vulgare subsp. vulgare) glutathione peroxidase 2 (HvGpx2) are demonstrated to display distinctly different functional properties in vitro. Monomeric HvGpx2 thus has five fold higher catalytic efficiency than the dimer towards tert-butyl hydroperoxide, but is more sensitive to inactivation by hydrogen peroxide. Treatment of the monomer with hydrogen peroxide results in dimer formation. This observed new behavior of a plant glutathione peroxidase suggests a mechanism involving a switch from a highly catalytically competent monomer to a less active, but more oxidation-resistant dimer.
authors: Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Building 224, DK-2800 Kgs. Lyngby, Denmark.
authors: Nicolas
authors: N
authors: Navrot
authors: Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Building 224, DK-2800 Kgs. Lyngby, Denmark.
authors: Nicklas
authors: N
authors: Skjoldager
authors: Center of Experimental BioInformatics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark; Department of Clinical Biochemistry, Copenhagen University Hospital Hvidovre, DK-2650 Hvidovre, Denmark.
authors: Jakob
authors: J
authors: Bunkenborg
authors: Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Building 224, DK-2800 Kgs. Lyngby, Denmark.
authors: Birte
authors: B
authors: Svensson
authors: Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Building 224, DK-2800 Kgs. Lyngby, Denmark. Electronic address: ph@bio.dtu.dk.
authors: Per
authors: P
authors: Hägglund
mesh_terms: D000222:Adaptation, Physiological; D019281:Dimerization; D005978:Glutathione / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism*; D001467:Hordeum / Q000201:enzymology* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010544:Peroxidases / Q000378:metabolism*; D054464:Peroxiredoxins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism*; D020122:tert-Butylhydroperoxide / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide; D010544:Peroxidases; C070881:barley peroxidase; D054464:Peroxiredoxins; D005979:Glutathione Peroxidase; D005978:Glutathione
keywords: Alkyl peroxide; Antioxidant; Glutathione peroxidase; Hydrogen peroxide; Oligomerization; Thioredoxin