FUNCTIONS AND PROPERTIES OF (2FE-2S) CENTERS

含Fe2(MU2-S)2核([2Fe-2S])的铁硫团簇 自然界中最普遍的电子载体之一，是不可或缺的 呼吸线粒体复合体I、II和III的组成 链条。最近的研究也表明(2Fe-2S)参与了 在铁-硫簇组装中，铁插入到卟啉中以 从脱硫代生物素、质子合成生物素 易位，氧化应激反应的调节过程和 脱水酶反应，尽管[2Fe-2S]团簇的确切作用 在这些重要的生物过程中的作用尚未得到充分的定义。这个 这项研究的长期目标是详细了解 生物(2Fe-2S)物理化学性质的分子水平 中心，特别强调决定中间点的因素 它们的潜力和它们明显的功能多样性的来源。 最终，这将有助于加深对人类起源的理解 原卟啉和与呼吸抑制相关的疾病 链状酵素。 该方法涉及到使用生物物理光谱技术、电子 顺磁共振、紫外可见/近红外吸收、圆二色谱 以及磁感应圆二色谱和共振拉曼光谱 研究了[2Fe-2S]的电子、磁性和结构性质 以多种天然和突变的酶和蛋白质为中心。这些 包括人和蓝藻铁氧还蛋白、人铁络合酶 菠菜二羟基酸脱水酶、大肠杆菌生物素合成酶、 棕色固氮杆菌nifu基因产物。此外，酶和 从化合物I、II和III中提取的蛋白质或与之密切相关的蛋白质 将对线粒体呼吸链进行调查，即个体 脱氮副球藻NADH脱氢酶亚基的研究 富马酸还原酶及其可溶性Rieske蛋白片段的研究 牛心脏线粒体。

Iron-sulfur clusters containing a Fe2(mu2-S)2 core ([2Fe-2S] clusters) are one of the most ubiquitous electron carriers in nature and are integral components of Complex I, II, and III of the mitochondrial respiratory chain. Recent studies have also implicated the involvement of (2Fe-2S] clusters in iron-sulfur cluster assembly, iron insertion into porphyrin to form hemes, the synthesis of biotin from dethiobiotin, proton translocation, regulatory processes in response to oxidative stress and dehydratase reactions, although the precise role of the [2Fe-2S] clusters in these important biological processes has yet to be fully defined. The long-term goal of this research is a detailed understanding at the molecular level of the physicochemical properties of biological (2Fe-2S] centers with particular emphasis on the factors determining midpoint potential and the origin of their apparent functional diversity. Ultimately this will lead to enhanced understanding of the origin of human protoporphyria and diseases associated with inhibition of the respiratory chain enzymes. The approach involves using biophysical spectroscopic techniques, electron paramagnetic resonance, UV/visible/near-IR absorption, circular dichroism and magnetically induced circular dichroism, and resonance Raman, to investigate the electronic, magnetic and structural properties of [2Fe-2S] centers in a wide range of native and mutated enzymes and proteins. These include human and cyanobacterial ferredoxins, human ferrochelatase, spinach dihydroxyacid dehydratase, Escherichia coil biotin synthase, the Azotobacter vinelandii nifU gene product. In addition, enzymes and proteins extracted from or closely related to Complex I, II and III of the mitochondrial respiratory chain will be investigated, i.e. individual subunits of Paracoccus denitrificans NADH dehydrogenase, Escherichia coli fumarate reductase and a soluble Rieske protein fragment isolated from bovine heart mitochondria.