The role of FeS-glutaredoxins and their cofactors in diseases

FeS簇是由蛋白质配体结合的辅因子，主要是半胱氨酰和组氨酰残基，并且对于相应蛋白质的酶活性或生物活性是必需的。这些范例发生变化后，确定的FeS配位谷氧还蛋白（Grxs）：Grxs协调FeS簇之间的两个单体使用两个分子的非共价键结合的谷胱甘肽和两个蛋白质硫醇的活性位点作为配体。FeS结合因此抑制作为氧化还原酶的酶活性。在我们鉴定出人类Grx 2作为第一个FeS-Grx之后，所有生命王国中的许多其他Grx都被鉴定为FeS配位蛋白。虽然已经确定了FeS-Grxs的几个基本功能，例如在脊椎动物发育，FeS簇生物合成和铁运输过程中，协调辅因子的独特分子作用在很大程度上仍然未知。在我们提出的项目中，我们将研究Grx协调的FeS簇在两种不同的疾病中的作用，这些疾病与铁稳态失调有关：多发性硬化症和心脏肥大。我们将联合收割机体外技术（生物化学和各种光谱方法）与离体（原代细胞培养，器官型切片培养）和体内模型（多发性硬化症，心脏肥大和铁过载的动物模型）以及患者材料相结合。为了达到我们的目标，我们可以参考我们在Grxs方面的专业知识，特别是FeS-Grxs的结构/功能关系。这些知识为构建特定突变形式的Grx提供了基础，这些突变形式在协调FeS簇的能力和酶活性方面有所不同。使用这些突变的Grx，我们已经能够证明一氧化氮解毒作为Grx协调的FeS簇的新功能。深入表征一氧化氮依赖的拆卸holo-Grxs将是我们的项目的重点之一，第一次全面调查的作用FeS集群协调哺乳动物Grxs。该蛋白质家族在FeS研究中的重要性日益增加，这一点被1927年优先计划中针对FeS-Grxs的大量应用网络所强调。

FeS cluster are cofactors bound by protein ligands, mainly cysteinyl and histidyl residues, and essential for enzymatic or biological activity of the respective proteins. These paradigms changed after the identification of FeS coordinating glutaredoxins (Grxs): Grxs coordinate FeS cluster between two monomers using two molecules of non-covalently bound glutathione and two protein thiols in the active site as ligands. FeS binding thus inhibits enzymatic activity as oxidoreductase. Following our identification of human Grx2 as the first FeS-Grx, numerous other Grxs in all kingdoms of life have been characterized as FeS coordinating proteins. Although several essential functions of FeS-Grxs have been identified, e.g. during vertebrate development, FeS cluster biosynthesis, and iron trafficking, the distinct molecular role of the coordinated cofactor remains largely unknown. In our proposed project we will investigate the role of Grx coordinated FeS cluster in two different diseases connected to disturbed iron homeostasis: multiple sclerosis and cardiac hypertrophy. We will combine in vitro techniques (biochemistry and a variety of spectroscopic methods) with ex vivo (primary cell cultures, organotypic slice cultures) and in vivo models (animal models for multiple sclerosis, cardiac hypertrophy, and iron overload) as well as patient material. To reach our goals, we can refer to our well documented expertise in Grxs in general, and structure/function relationship of FeS-Grxs in particular. This knowledge provided the base for the construction of specific mutated forms of Grxs that differ in their ability to coordinate the FeS cluster and their enzymatic activity. Using these mutated Grxs we were already able to demonstrate nitric oxide detoxification as new function of Grx coordinated FeS cluster. The in-depth characterization of the nitric oxide-dependent disassembly of holo-Grxs will be one of the emphases of our project, the first comprehensive investigation of the role of FeS cluster coordinated by mammalian Grxs. The increasing importance of this protein family in FeS research is emphasised by the substantial network of applications to the priority program 1927 that address FeS-Grxs.