Kotlyar A B, Vinogradov A D
Department of Biochemistry, School of Biology, Moscow State University, USSR.
FEBS Lett. 1989 Mar 27;246(1-2):17-20. doi: 10.1016/0014-5793(89)80244-3.
The homogeneous bovine heart mitochondrial high-molecular-mass oxaloacetate keto-enol tautomerase [(1988) Biochim. Biophys. Acta 936, 10-19] is shown to be an iron-sulfur protein as revealed by the enzyme spectral properties and direct chemical determination of non-heme iron and acid-labile sulfur. The protein is capable of catalysing the aconitase reaction after treatment with ferrous ions under anaerobic conditions. Treatment of the 'activated' protein with N-ethylmaleimide results in the simultaneous irreversible loss of the oxaloacetate keto-enol tautomerase and aconitase activities. The effects of some substrates and inhibitors on both activities show that the same catalytic site is involved in the oxaloacetate tautomerase and aconitase reactions. It is concluded that the protein previously described as a 80 kDa oxaloacetate keto-enol tautomerase is inactive aconitase.
已证明，如通过酶光谱特性以及非血红素铁和酸不稳定硫的直接化学测定所揭示的那样，均一的牛心线粒体高分子量草酰乙酸酮 - 烯醇互变异构酶[（1988年）《生物化学与生物物理学报》936，10 - 19]是一种铁硫蛋白。该蛋白在厌氧条件下用亚铁离子处理后能够催化乌头酸酶反应。用N - 乙基马来酰亚胺处理“活化”蛋白会导致草酰乙酸酮 - 烯醇互变异构酶和乌头酸酶活性同时不可逆丧失。一些底物和抑制剂对这两种活性的影响表明，草酰乙酸互变异构酶和乌头酸酶反应涉及相同的催化位点。得出的结论是，先前被描述为80 kDa草酰乙酸酮 - 烯醇互变异构酶的蛋白是无活性的乌头酸酶。
