Navrot Nicolas, Skjoldager Nicklas, Bunkenborg Jakob, Svensson Birte, Hägglund Per
Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Building 224, DK-2800 Kgs. Lyngby, Denmark.
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.
Plant Physiol Biochem. 2015 May;90:58-63. doi: 10.1016/j.plaphy.2015.03.003. Epub 2015 Mar 10.
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.
已证明重组大麦（普通大麦亚种）谷胱甘肽过氧化物酶2（HvGpx2）的单体和二聚体形式在体外表现出明显不同的功能特性。因此，单体HvGpx2对叔丁基过氧化氢的催化效率比二聚体高五倍，但对过氧化氢失活更敏感。用过氧化氢处理单体导致二聚体形成。这种观察到的植物谷胱甘肽过氧化物酶的新行为表明了一种机制，即从具有高催化活性的单体转变为活性较低但抗氧化性更强的二聚体。
