A Novel Selenocystine--Cyclodextrin Conjugate That Acts as a Glutathione Peroxidase Mimic
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- 作者：Xiaojun Ren ; Junqiu Liu ; Guimin Luo ; Yan Zhang ; Yuanming Luo ; Ganglin Yan ; and Jiacong Shen
- 刊名：Bioconjugate Chemistry
- 出版年：2000
- 出版时间：September 2000
- 年：2000
- 卷：11
- 期：5
- 页码：682 - 687
- 全文大小：75K
- 年卷期：v.11,no.5(September 2000)
- ISSN：1520-4812
文摘
A novel artificial glutathione peroxidase mimic consisting of a selenocystine-di-
-cyclodextrin conjugate(selenium-bridged-6,6'-amino-selenocystine-6,6'-deoxy-di--cyclodextrin), in which selenocystine isbound to the primary side of -cyclodextrin through the two amino nitrogen groups of selenocystine,was synthesized. The glutathione peroxidase activities of the mimic-catalyzed reduction of H2O2, tert-butylhydroperoxide, and cumene hydroperoxide by glutathione are 4.1, 2.11, and 5.82 units/
mol,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 suggestthat it is important to consider substrate binding in designing glutathione peroxidase mimics. Thedetailed steady-state kinetic studies showed that the mimic-catalyzed reduction of H2O2 by glutathionefollowed a ping-pong mechanism, which was similar to that of the native glutathione peroxidase.
-cyclodextrin conjugate(selenium-bridged-6,6'-amino-selenocystine-6,6'-deoxy-di--cyclodextrin), in which selenocystine isbound to the primary side of -cyclodextrin through the two amino nitrogen groups of selenocystine,was synthesized. The glutathione peroxidase activities of the mimic-catalyzed reduction of H2O2, tert-butylhydroperoxide, and cumene hydroperoxide by glutathione are 4.1, 2.11, and 5.82 units/mol,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 suggestthat it is important to consider substrate binding in designing glutathione peroxidase mimics. Thedetailed steady-state kinetic studies showed that the mimic-catalyzed reduction of H2O2 by glutathionefollowed a ping-pong mechanism, which was similar to that of the native glutathione peroxidase.