Solubility and Supersaturation-Dependent Protein Misfolding Revealed by Ultrasonication
Solubility and Supersaturation-Dependent Protein Misfolding Revealed by Ultrasonication
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DOI：
10.1021/la403100h
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发表时间：
2014-02-25
期刊：
影响因子：
3.9
通讯作者：
Goto, Yuji
中科院分区：
文献类型：
--
作者：
Lin, Yuxi;Lee, Young-Ho;Goto, Yuji
虽然醇类是产生淀粉样纤维的有用的助溶剂，但醇依赖性纤维化的潜在机制尚不清楚。本文研究了不同浓度的乙醇、2，2，2-三氟乙醇（TFE）和1，1，1，3，3，3-六氟-2-丙醇（HFIP）对鸡蛋清溶菌酶纤维化的影响。在醇变性的溶菌酶保持亚稳定性的条件下，超声处理有效地引发原纤化。最佳酒精浓度取决于酒精种类。HFIP在12- 16%处显示出急剧的最大值。对于TFE，观察到40-80%的宽最大值。乙醇仅表现出高于60%的原纤化增加。这些配置文件是相反的溶菌酶在水/醇混合物中的平衡溶解度。结果表明，虽然原纤化是由溶解度，过饱和防止构象转变和超声波处理是非常有效的，在最大限度地减少过饱和的影响。我们提出了一个酒精依赖性蛋白质错误折叠漏斗用于检查淀粉样蛋白。这种错误折叠漏斗将适用于生理条件下的原纤化，其中生物环境在降低溶解度中起重要作用。
Although alcohols are useful cosolvents for producing amyloid fibrils, the underlying mechanism of alcohol-dependent fibrillation is unclear. We studied the alcohol-induced fibrillation of hen egg-white lysozyrne at various concentrations of ethanol, 2,2,2-trifluoroethanol (TFE), and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Under the conditions where the alcohol-denatured lysozyme retained metastability, ultrasonication effectively triggered fibrillation. The optimal alcohol concentration depended on the alcohol species. HFIP showed a sharp maximum at 12-16%. For TFE, a broad maximum at 40-80% was observed. Ethanol exhibited only an increase in fibrillation above 60%. These profiles were opposite to the equilibrium solubility of lysozyme in water/alcohol mixtures. The results indicate that although fibrillation is determined by solubility, supersaturation prevents conformational transitions and ultrasonication is highly effective in minimizing an effect of supersaturation. We propose an alcohol-dependent protein misfolding funnel useful for examining amyloidogenicity. This misfolding funnel will apply to fibrillation under physiological conditions where biological environments play important roles in decreasing the solubility.