JInclPhenomMacro--A glutathione peroxidase mimic 6,6 ''-ditellurobis (6-deoxy-beta-cyclodextrin) with high substrate specificity
作者：Dong, ZY; Liu, JQ; Mao, SZ; et al.
關(guān)鍵字：Glutathione peroxidase, Cyclodextrin, Enzyme models, Catalysis
論文來源：期刊
發(fā)表時間：2006年
Glutathione peroxidase (GPx) is one of the most
important antioxidative selenoenzymes in living organisms. The novel GPx mimic 6,6’-ditellurobis(6-deoxy-b-cyclodextrin) (6-TeCD) was prepared and evaluated for
its capacity to catalyze the reduction of H2O2, tert-butyl hydroperoxide (t-BuOOH), and cumene hydroperoxide (CuOOH) by
glutathione (GSH) or 3-carboxy-4-nitrobenzenethiol (ArSH). Compared the ArSH
assay with the coupled reductase assay, 6-TeCD exhibited strong substrate specificity for
aromatic thiol substrate. The specificity led to efficient peroxidase activity almost
100,000-fold than that for a well-known GPx mimic diphenyl diselenide
(PhSeSePh). Furthermore, reduction of lipophilic CuOOH proceeded ca. 30 times faster than
the more hydrophilic H2O2, which cannot bind into the
hydrophobic cavity of b-cyclodextrin. Thus, it seems that catalytic activity of
cyclodextrin-derived GPx models strongly depends on the structurally different
both substrates hydroperoxides (ROOH) and thiols.