Kinetics and polymorphs of yeast prion Sup35NM amyloidogenesis
Kinetics and polymorphs of yeast prion Sup35NM amyloidogenesis
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酵母朊病毒Sup35NM淀粉样变的动力学和多态性
DOI：
10.1016/j.ijbiomac.2017.05.001
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发表时间：
2017
影响因子：
8.2
通讯作者：
Lee Young-Ho
中科院分区：
文献类型：
--
作者：
Kinoshita Misaki;Lin Yuxi;Nakatsuji Masatoshi;Inui Takashi;Lee Young-Ho
淀粉样蛋白通常形成多种类型的聚集体，这是细胞毒性和组织特异性的关键决定因素。然而，不同淀粉样蛋白产生的分子机制及其对细胞的影响仍然很大程度上未知。我们在此研究了酵母朊病毒蛋白 Sup35NM（Sup35 的本质无序 N 末端片段）在各种条件下的多态性淀粉样蛋白形成及其与细胞毒性的潜在关系。 Sup35NM 聚集成淀粉样原纤维，具有不同的动力学、结构、形态、着色特性和构象稳定性，具体取决于 NaCl 浓度、pH 和温度，表明 Sup35NM 的多态性淀粉样蛋白生成。 Sup35NM 淀粉样蛋白形成的详细动力学分析表明，滞后时间和伸长率之间存在很强的负相关性，而动力学参数和结构参数之间不存在相关性。这些结果表明，由于不同的成核和伸长率导致的动力学多态性导致淀粉样原纤维的结构多态性，并且增强或抑制Sup35NM成核的条件促进或延迟原纤维生长。多态性 Sup35NM 淀粉样原纤维对膜完整性和细胞活力的有害影响很小。我们假设 Sup35NM 淀粉样原纤维的无害多态性可能有利于在细胞死亡之前赢得朊病毒感染的时间。
Amyloidogenic proteins often form many types of aggregates, which are a critical determinant of cytotoxicity and tissue specificity. However, the molecular mechanisms underlying the generation of distinct amyloids and their influence on cells remain largely unknown. We herein investigated the polymorphic amyloid formation of the yeast prion protein, Sup35NM, an intrinsically disordered N-terminal fragment of Sup35, under various conditions and its potential relationship to cytotoxicity. Sup35NM aggregated to amyloid fibrils with distinct kinetics, structures, morphologies, tinctorial properties, and conformational stabilities depending on the concentration of NaCl, pH, and temperature, indicating the polymorphic amyloidogenesis of Sup35NM. Detailed kinetic analyses of Sup35NM amyloid formation revealed a strong inverse correlation between the lag time and elongation rate without a correlation between kinetic and structural parameters. These results suggest that kinetic polymorphisms due to distinct nucleation and elongation rates result in structural polymorphs of amyloid fibrils, and also that conditions that enhance or inhibit the nucleation of Sup35NM promote or delay fibril growth. The deleterious effects of polymorphic Sup35NM amyloid fibrils on membrane integrity and cell vitality were minimal. We hypothesize that the innocuous polymorphic nature of Sup35NM amyloid fibrils may be beneficial for gaining time for prion infection prior to cell death.