Analysis of Toxic Amyloid Fibril Interactions at Natively Derived Membranes by Ellipsometry.
Analysis of Toxic Amyloid Fibril Interactions at Natively Derived Membranes by Ellipsometry.
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DOI：
10.1371/journal.pone.0132309
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Smith DP
中科院分区：
文献类型：
--
作者：
Smith RA;Nabok A;Blakeman BJ;Xue WF;Abell B;Smith DP
关于与淀粉样蛋白紊乱相关的细胞毒性的罪魁祸首，还有一场持续的辩论。虽然小的纤维前淀粉样寡聚体被认为是主要的有毒物质，但纤维淀粉样物质本身也可以引起细胞毒性。为了研究与完整和破碎的纤维相关的膜破裂和细胞毒性效应，使用了新的全内反射椭圆偏振光谱仪(TIRE)原位光谱技术。使用天然来源的全细胞膜作为体内环境的模型来监测纤维状脂的相互作用。我们表明，与未破碎的纤维相比，碎裂的纤维具有更强的破坏这些天然来源的膜的能力，因为它会导致沉积表面的物质损失。活细胞膜破裂的观察和使用合成脂质体的染料释放试验证实了这一效应。通过这些研究，我们展示了利用轮胎来分析天然来源的脂质表面的蛋白质-脂质相互作用，并解释了淀粉样蛋白纤维如何导致有毒的功能获得，而缠绕的淀粉样蛋白斑块发挥最小的生物活性。
There is an ongoing debate regarding the culprits of cytotoxicity associated with amyloid disorders. Although small pre-fibrillar amyloid oligomers have been implicated as the primary toxic species, the fibrillar amyloid material itself can also induce cytotoxicity. To investigate membrane disruption and cytotoxic effects associated with intact and fragmented fibrils, the novel in situ spectroscopic technique of Total Internal Reflection Ellipsometry (TIRE) was used. Fibril lipid interactions were monitored using natively derived whole cell membranes as a model of the in vivo environment. We show that fragmented fibrils have an increased ability to disrupt these natively derived membranes by causing a loss of material from the deposited surface when compared with unfragmented fibrils. This effect was corroborated by observations of membrane disruption in live cells, and by dye release assay using synthetic liposomes. Through these studies we demonstrate the use of TIRE for the analysis of protein-lipid interactions on natively derived lipid surfaces, and provide an explanation on how amyloid fibrils can cause a toxic gain of function, while entangled amyloid plaques exert minimal biological activity.