A redox-dependent dimerization switch regulates activity and tolerance for reactive oxygen species of barley seed glutathione peroxidase

作者：Navrot Nicolas; Skjoldager Nicklas; Bunkenborg Jakob; Svensson Birte; Hagglund Per^*

来源：Plant Physiology and Biochemistry, 2015, 90: 58-63.

DOI：10.1016/j.plaphy.2015.03.003

• Glutathione peroxidase
• Thioredoxin
• Antioxidant
• Hydrogen peroxide
• Alkyl peroxide
• Oligomerization

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.

• 出版日期2015-5