The formation of amyloid fibrils from soluble proteins is a common form of self-assembly phenomenon that has fundamental connections with biological functions and human diseases. Lysozyme was converted from its soluble native state into highly organized amyloid fibrils. Ultrasonic treatment was used to break amyloid fibrils to fibrillar fragments-seeds. Atomic force microscopy and fluorescence microscopy was employed to characterize the morphology of the amyloid assemblies and neural cells-amyloid complexes. Our results demonstrate that prefibrillar intermediated and their mixture with proteins exhibit toxicity, although native proteins and fibrils appear to have no effect on number of cells. Our findings confirm that innocuous hen lysozyme can be engineered to produce both cytotoxic fibrillar fragments and non-toxic mature amyloid fibrils. Our work further strengthens the claim that amyloid conformation, and not the identity of the protein, is key to cellular toxicity and the underlying specific cell death mechanism.

中文翻译：

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淀粉样蛋白片段及其对神经细胞的毒性。

由可溶性蛋白质形成淀粉样蛋白原纤维是自组装现象的一种常见形式，与生物学功能和人类疾病有着根本的联系。溶菌酶从其可溶性天然状态转变为高度组织化的淀粉样原纤维。超声处理用于将淀粉样蛋白原纤维破碎成原纤维碎片种子。使用原子力显微镜和荧光显微镜来表征淀粉样蛋白组装体和神经细胞-淀粉样蛋白复合物的形态。我们的结果表明，原纤维中间体及其与蛋白质的混合物显示出毒性，尽管天然蛋白质和原纤维似乎对细胞数量没有影响。我们的发现证实，无害的母鸡溶菌酶可以被工程化以产生细胞毒性原纤维片段和无毒成熟淀粉样蛋白原纤维。