Zinc binding sites in Pra1, a zincophore from Candida albicans
Zinc binding sites in Pra1, a zincophore from Candida albicans
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DOI：
10.1039/c7dt01675a
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发表时间：
2017-10-28
影响因子：
4
通讯作者：
Rowinska-Zyrek, Magdalena
中科院分区：
文献类型：
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作者：
Loboda, Dorota;Rowinska-Zyrek, Magdalena
这项工作的目的是了解锌（II）与Pra 1的相互作用，Pra 1是白色念珠菌的锌载体，是人类严重真菌感染的最常见原因之一。Pra 1是一种由299个氨基酸组成的蛋白质，由真菌分泌，特异性结合Zn（II）并将其传递给跨膜锌转运蛋白Zrt 1。我们采取的第一步，了解这个过程中的生物无机化学，通过指出锌（II）结合位点的Pra 1和理解这种相互作用的热力学。我们的方法涉及模型系统（蛋白质的非结构化部分），以确定Pra 1中锌以最高亲和力结合的区域。质谱显示的化学计量的Zn（II）-肽复合物的形成和电位的研究给我们的部分和整体的稳定常数为所有形成的锌络合物。NMR澄清结合位点的情况下，怀疑。这些结果的详细比较表明，Pra 1的C-末端区域结合Zn（II）具有最高的亲和力，表明锌载体的该区域负责锌的结合。这些知识是锌的基本生物无机化学的输入;它使我们能够了解锌载体的无机生物化学，并且它可能是基于锌载体部分与抗真菌药物结合的新的真菌特异性治疗方法的垫脚石。
The aim of this work is to understand the interactions of Zn(II) with Pra1, a zincophore from Candida albicans, one of the most common causes of serious fungal infections in humans. Pra1 is a 299 amino acid protein, secreted from the fungus to specifically bind Zn(II) and deliver it to a transmembrane zinc transporter, Zrt1. We take the first step towards understanding the bioinorganic chemistry of this process, by pointing out the Zn(II) binding sites in Pra1 and understanding the thermodynamics of such interactions. Our approach involves working on model systems (unstructured parts of proteins) in order to identify those regions in Pra1, to which zinc binds with the highest affinity. Mass spectrometry shows the stoichiometry of Zn(II)-peptide complex formation and potentiometric studies give us the partial and overall stability constants for all the formed zinc complexes. NMR clarifies binding sites in the case of doubts. A detailed comparison of these results shows that the C-terminal region of Pra1 binds Zn(II) with the highest affinity, indicating that this region of the zincophore is responsible for the binding of zinc. Such knowledge is an input to the basic bioinorganic chemistry of zinc; it allows us to understand the inorganic biochemistry of zincophores, and it might be a stepping stone towards finding new, fungus specific treatments based on parts of zincophores coupled with antifungal drugs.