A novel selenocystine-beta-cyclodextrin conjugate that acts as a glutathione peroxidase mimic.
A novel artificial glutathione peroxidase mimic consisting of a selenocystine-di-beta-cyclodextrin conjugate (selenium-bridged-6, 6'-amino-selenocystine-6,6'-deoxy-di-beta-cyclodextrin), in which selenocystine is bound to the primary side of beta-cyclodextrin through the two amino nitrogen groups of selenocystine, was synthesized. The glutathione peroxidase activities of the mimic-catalyzed reduction of H(2)O(2), tert-butylhydroperoxide, and cumene hydroperoxide by glutathione are 4.1, 2.11, and 5.82 units/micromol, respectively. The first activity was 82 and 4.2 times as much as that of selenocysteine and ebselen, respectively. Studies on the effect of substrate binding on the glutathione peroxidase activity suggest that it is important to consider substrate binding in designing glutathione peroxidase mimics. The detailed steady-state kinetic studies showed that the mimic-catalyzed reduction of H(2)O(2) by glutathione followed a ping-pong mechanism, which was similar to that of the native glutathione peroxidase.
Ren
X
X
Key Laboratory of Molecular Enzymology and Engineering, Jilin University, Changchun 130023, China.
Liu
J
J
Luo
G
G
Zhang
Y
Y
Luo
Y
Y
Yan
G
G
Shen
J
J
D001665:Binding Sites; D002384:Catalysis; D003505:Cyclodextrins / Q000737:chemistry*; D005978:Glutathione / Q000737:chemistry*; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006861:Hydrogen Peroxide; D007202:Indicators and Reagents; D007700:Kinetics; D012643:Selenium / Q000737:chemistry*; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D007202:Indicators and Reagents; D047392:beta-Cyclodextrins; C415746:selenium-bridged-6,6'-amino-selenocystine-6,6'-deoxy-di-beta-cyclodextrin; D006861:Hydrogen Peroxide; D005979:Glutathione Peroxidase; D005978:Glutathione; D012643:Selenium