A Water-Soluble Cyclic Selenide with Enhanced Glutathione Peroxidase-Like Catalytic Activities
A Water-Soluble Cyclic Selenide with Enhanced Glutathione Peroxidase-Like Catalytic Activities
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DOI：
10.1002/ejoc.200901114
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发表时间：
2010-01-01
影响因子：
2.8
通讯作者：
Iwaoka, Michio
中科院分区：
文献类型：
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作者：
Kumakura, Fumio;Mishra, Beena;Iwaoka, Michio
研究了水溶性环硒化物反式-3，4-二羟基硒环戊烷（DHSred）在过氧化氢与三种不同巯基底物（单巯基谷胱甘肽（GSH）、二巯基二硫苏糖醇（DTTred）和多肽链上沿着有八个巯基的多巯基还原核糖核酸酶A（RNase A））反应中的抗氧化催化活性。DHSred表现出比相应的线性硒化物更高的谷胱甘肽过氧化物酶（GPx）样抗氧化催化活性，即，Se（CH 2CH 2 OH）（2）速率-催化循环的决定步骤被明确地分配给硒化物的氧化过程，而不是硒氧化物中间体的还原过程。DHSred的环状结构提高了HOMO能级，使硒原子更多地暴露于环境中，从而提高了其催化活性。
Antioxidative catalytic activities of trans-3,4-dihydroxyselenolane (DHSred), a water-soluble cyclic selenide, were investigated in the reaction of hydrogen peroxide with three different thiol substrates, monothiol glutathione (GSH), dithiol dithiothreitol (DTTred), and polythiol reduced ribonuclease A (RNase A) having eight thiol groups along the polypeptide chain For all the thiol substrates, DHSred exhibited higher glutathione peroxidase (GPx)-like antioxidative catalytic activities than the corresponding linear selenide, that is, Se(CH2CH2OH)(2) The rate-determining step of the catalytic cycle was unambiguously assigned to the oxidation process of the selenide rather than the reduction process of the selenoxide intermediate The enhanced catalytic activities of DHSred can be ascribed to the cyclic structure, which elevates the HOMO energy level and makes the selenium atom more exposed to the surroundings.