CHEMICAL CHARACTERIZATION OF SELENOPROTEIN COMPONENT OF CLOSTRIDIAL GLYCINE REDUCTASE - IDENTIFICATION OF SELENOCYSTEINE AS ORGANOSELENIUM MOIETY
CHEMICAL CHARACTERIZATION OF SELENOPROTEIN COMPONENT OF CLOSTRIDIAL GLYCINE REDUCTASE - IDENTIFICATION OF SELENOCYSTEINE AS ORGANOSELENIUM MOIETY
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DOI：
10.1073/pnas.73.8.2659
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发表时间：
1976-01-01
影响因子：
11.1
通讯作者：
STADTMAN, TC
中科院分区：
文献类型：
--
作者：
CONE, JE;MARTINDELRIO, R;STADTMAN, TC
一个小的，热稳定的selenoprotein，甘氨酸还原酶复合物的一个组成部分，标记与75硒通过生长的Sticklandii在Na 275 SeO 3的存在下。含硒部分，这是必不可少的蛋白质的生物活性，是硒代半胱氨酸残基。它被分离为它的Se-羧甲基，Se-羧乙基和Se-氨乙基衍生物从纯的75 Se-标记的蛋白质，被还原，并在水解前用各种烷化剂处理的酶。在每种情况下，从烷基化蛋白质样品中获得的75 Se标记的部分和真实硒代半胱氨酸的相应烷基衍生物是不可区分的。几项研究表明，天然硒蛋白的发色团（UVmax 238 nm），出现在减少蛋白质与KBH 4和暴露于O2后迅速消失。这种O2-不稳定的发色团可能是硒代半胱氨酸残基的电离-SeH基团。
A small, heat-stable selenoprotein, a component of the glycine reductase complex, was labeled with 75Se by growth of Clostridium sticklandii in the presence of Na275SeO3. The Se-containing moiety, which is essential for the biological activity of the protein, was a selenocysteine residue. It was isolated as its Se-carboxymethyl, Se-carboxyethyl and Se-aminoethyl derivatives from digests of the pure 75Se-labeled protein that was reduced and treated with the various alkylating agents prior to hydrolysis. In each instance the 75Se-labeled moiety obtained from an alkylated protein sample and the corresponding alkyl derivative of authentic selenocysteine were indistinguishable. Several studies of the native selenoprotein showed a chromophore (UVmax 238 nm) that appeared upon reduction of the protein with KBH4 and rapidly disappeared upon exposure to O2. This O2-labile chromophore is probably the ionized -SeH group of the selenocysteine residue.