A Nonheme High-Spin Ferrous Pool in Mitochondria Isolated from Fermenting Saccharomyces cerevisiae
A Nonheme High-Spin Ferrous Pool in Mitochondria Isolated from Fermenting Saccharomyces cerevisiae
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DOI：
10.1021/bi1001823
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发表时间：
2010-05-18
期刊：
影响因子：
2.9
通讯作者：
Lindahl, Paul A.
中科院分区：
文献类型：
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作者：
Holmes-Hampton, Gregory P.;Miao, Ren;Lindahl, Paul A.
穆斯堡尔谱被用来检测池的铁在线粒体发酵酵母细胞，包括那些组成的nonheme高自旋（HS）Fe-II物种，Fe-III纳米粒子，单核HS Fe-III物种。争论的焦点是这些物种是位于线粒体内部还是外部。没有一个可以通过用乙二醇四乙酸或红菲咯啉磺酸盐（BPS），铁-II螯合剂，似乎不穿透线粒体膜广泛洗涤线粒体。然而，当线粒体样品进行超声处理，BPS协调的Fe-II物种，形成一个低自旋的Fe-II复合物。这种治疗也减少了两种Fe-III物质的水平，表明所有这些Fe物质被线粒体膜包裹，并被保护免受听写，直到膜被破坏。1，10-菲咯啉是化学上类似的BPS，但膜可溶;它协调nonheme HS Fe-II在unsonicated线粒体。此外，HS Fe-III物质和纳米颗粒不被连二亚硫酸盐还原，直到添加去污剂脱氧胆酸盐以破坏膜。线粒体样品中非血红素HS Fe-II物种的百分比和污染蛋白质的水平之间没有相关性。这些结果共同表明，所观察到的Fe物质包含在线粒体内。整个细胞的穆斯堡尔谱主要由HS Fe-III特征;其余显示典型的分离线粒体的光谱特征，这表明发酵酵母细胞中的Fe可以粗略地分为两类：线粒体Fe和（大多数）HS Fe-III离子在一个或多个非线粒体位置。
Mossbauer spectroscopy was used to detect pools of Fe in mitochondria from fermenting yeast cells, including those consisting of nonheme high-spin (HS) Fe-II species, Fe-III nanoparticles, and mononuclear HS Fe-III species. At issue was whether these species were located within mitochondria or on their exterior. None could be removed by washing mitochondria extensively with ethylene glycol tetraacetic acid or bathophenanthroline sulfonate (BPS), Fe-II chelators that do not appear to penetrate mitochondrial membranes. However, when mitochondrial samples were sonicated, BPS coordinated the Fe-II species, forming a low-spin Fe-II complex. This treatment also diminished the levels of both Fe-III species, suggesting that all of these Fe species are encapsulated by mitochondrial membranes and are protected from dictation until membranes are disrupted. 1,10-Phenanthroline is chemically similar to BPS but is membrane soluble; it coordinated nonheme HS Fe-II in unsonicated mitochondria. Further, the HS Fe-III species and nanoparticles were not reduced by dithionite until the detergent deoxycholate was added to disrupt membranes. There was no correlation between the percentage of nonheme HS Fe-II species in mitochondrial samples and the level of contaminating proteins. These results collectively indicate that the observed Fe species are contained within mitochondria. Mossbauer spectra of whole cells were dominated by HS Fe-III features; the remainder displayed spectral features typical of isolated mitochondria, suggesting that the Fe in fermenting yeast cells can be coarsely divided into two categories: mitochondrial Fe and (mostly) HS Fe-III ions in one or more non-mitochondrial locations.