Effect of spermidine on misfolding and interactions of alpha-synuclein.
Effect of spermidine on misfolding and interactions of alpha-synuclein.
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DOI：
10.1371/journal.pone.0038099
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Lyubchenko YL
中科院分区：
文献类型：
--
作者：
Krasnoslobodtsev AV;Peng J;Asiago JM;Hindupur J;Rochet JC;Lyubchenko YL
α-突触核蛋白 (α-Syn) 是一种 140 个氨基酸的突触前蛋白，属于一组在水溶液中非结构化的天然未折叠蛋白。当细胞多胺达到生理水平时，α-Syn 的聚集速率会加快。在这里，我们应用单分子 AFM 力谱来表征亚精胺对 α-Syn 聚集的第一阶段（错误折叠和组装成二聚体）的影响。研究了两种 α-Syn 变体：野生型 (WT) 蛋白和 A30P。这两种蛋白质分子共价固定在 C 末端，一种固定在 AFM 尖端，另一种固定在基底上，通过多次接近-回缩循环测量两种分子之间的分子间相互作用。在接近生理条件的条件下，α-Syn 错误折叠是罕见的，添加亚精胺会导致 WT 和突变蛋白错误折叠的倾向急剧增加。重要的是，错误折叠的特征是一组构象，A30P 改变错误折叠模式以及分子间相互作用的强度。加上亚精胺促进 α-Syn 聚集的后期这一事实，我们的数据表明，亚精胺促进蛋白质聚集的早期阶段，包括 α-Syn 错误折叠和二聚化。这一发现表明，亚精胺和其他潜在多胺水平的增加可以启动与疾病相关的 α-Syn 过程。
Alpha-synuclein (α-Syn) is a 140 aa presynaptic protein which belongs to a group of natively unfolded proteins that are unstructured in aqueous solutions. The aggregation rate of α-Syn is accelerated in the presence of physiological levels of cellular polyamines. Here we applied single molecule AFM force spectroscopy to characterize the effect of spermidine on the very first stages of α-Syn aggregation – misfolding and assembly into dimers. Two α-Syn variants, the wild-type (WT) protein and A30P, were studied. The two protein molecules were covalently immobilized at the C-terminus, one at the AFM tip and the other on the substrate, and intermolecular interactions between the two molecules were measured by multiple approach-retraction cycles. At conditions close to physiological ones at which α-Syn misfolding is a rare event, the addition of spermidine leads to a dramatic increase in the propensity of the WT and mutant proteins to misfold. Importantly, misfolding is characterized by a set of conformations, and A30P changes the misfolding pattern as well as the strength of the intermolecular interactions. Together with the fact that spermidine facilitates late stages of α-Syn aggregation, our data demonstrate that spermidine promotes the very early stages of protein aggregation including α-Syn misfolding and dimerization. This finding suggests that increased levels of spermidine and potentially other polyamines can initiate the disease-related process of α-Syn.
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DOI：
10.1073/pnas.0407146102
发表时间：
2005-02-01
影响因子：
11.1
作者：
Bertoncini, CW;Jung, YS;Zweckstetter, M
通讯作者：
Zweckstetter, M
影响因子：
4.8
作者：
Antony, T;Hoyer, W;Subramaniam, V
通讯作者：
Subramaniam, V
影响因子：
2.9
作者：
Conway, KA;Harper, JD;Lansbury, PT
通讯作者：
Lansbury, PT
影响因子：
56.9
作者：
Conway, KA;Rochet, JC;Lansbury, PT
通讯作者：
Lansbury, PT
影响因子：
4.8
作者：
Bertoncini, CW;Fernandez, CO;Zweckstetter, M
通讯作者：
Zweckstetter, M