We present colloidal nanocomposites formed by incorporating magnetite Fe3 O4 nanoparticles (MNPs) with lysozyme amyloid fibrils (LAFs). Preparation of two types of solutions, with and without addition of salt, was carried out to elucidate the structure of MNPs-incorporated fibrillary nanocomposites and to study the effect of the presence of salt on the stability of the nanocomposites. The structural morphology of the LAFs and their interaction with MNPs were analyzed by atomic force microscopy and small-angle x-ray scattering measurements. The results indicate that conformational properties of the fibrils are dependent on the concentration of protein, and the precise ratio of the concentration of the protein and MNPs is crucially important for the stability of the fibrillary nanocomposites. Our results confirm that despite the change in fibrillary morphology induced by the varying concentration of the protein, the adsorption of MNPs on the surface of LAF is morphologically independent. Moreover, most importantly, the samples containing salt have excellent stability for up to 1 year of shelf-life.

中文翻译：

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蛋白质和纳米粒子浓度对生物杂化纳米复合材料结构的影响

我们提出了通过将磁铁矿 Fe3 O4 纳米粒子 (MNP) 与溶菌酶淀粉样蛋白原纤维 (LAF) 结合而形成的胶体纳米复合材料。制备两种类型的溶液，加盐和不加盐，以阐明掺入 MNP 的原纤维纳米复合材料的结构，并研究盐的存在对纳米复合材料稳定性的影响。通过原子力显微镜和小角度 X 射线散射测量分析了 LAF 的结构形态及其与 MNP 的相互作用。结果表明，原纤维的构象特性取决于蛋白质的浓度，蛋白质和 MNP 浓度的精确比例对于原纤维纳米复合材料的稳定性至关重要。我们的结果证实，尽管不同浓度的蛋白质引起纤维形态的变化，但 MNP 在 LAF 表面的吸附在形态上是独立的。此外，最重要的是，含盐样品在长达 1 年的保质期内具有出色的稳定性。