Elucidation and control of the molecular mechanism of amyloid fibril formation Applications for nano materials

本研究的目的是（1）通过对β-淀粉样蛋白和β 2-微球蛋白（β2-m）淀粉样蛋白的研究，建立淀粉样纤维形成和解离的一般分子模型;（2）阐明各种生物分子或化学化合物在各种淀粉样变性的共同发病机制中的作用，并提出了治疗策略（3）淀粉样蛋白原纤维形成和解离的控制方法的发明及其在纳米技术中的应用。结果：（1）6个肽段分别对应β2-m天然结构中7个β折叠中的6个，并检测了它们的淀粉样变性。在检测的肽中，肽（21-31）显示原纤维形成。(2)在β2-m淀粉样原纤维形成中，β2-m的部分解折叠被认为是其组装成Aβ 2 M淀粉样原纤维的先决条件。本研究发现，在中性pH条件下，低浓度的三氟乙醇和十二烷基硫酸钠可诱导β2-m淀粉样蛋白的部分去折叠，并导致Aβ 2 M淀粉样纤维的延伸。（3）多酚类或维生素A相关化合物可抑制β-淀粉样纤维的形成，并使预形成的纤维不稳定。(4)采用等温滴定量热法对淀粉样蛋白原纤维的形成进行了直接的热力学分析。这项研究使我们能够测量的热容和焓，并估计淀粉样蛋白在原纤维形成过程中的构象变化的稳定性和结构信息。本研究在阐明纤维形成的分子机制方面取得了显著进展。此外，淀粉样蛋白原纤维的形成和解离的应用纳米技术的有用特性被发现。

The aims of this study are (1) establishment of general molecular model of amyloid fibril formation and dissociation via the study of beta-amyloid and beta2-microglobulin (β2-m) amyloid (2) elucidation of the effect of various biological molecules or chemical compounds on the common pathogenesis of each amyloidosis, and suggest a strategy for treatment (3) invention of the control method for the formation and dissociation of amyloid fibril, and their application to nanotechnology. Results : (1) six peptides correspond to six of the seven beta sheet in the native structure of β2-m, and examined their amyloidogenisity. Among the peptides examined, peptide(21-31) showed fibril formation. (2) in β2-m amyloid fibril formation, partial unfolding of β2-m is believed to be prerequisite to its assembly into Aβ2M amyloid fibrils. In this study, low concentrations of trifluoroethanol and sodium dodecyl sulfate was found to induce the amyloidogenic partial unfolding of β2-m and result in the extension of Aβ2M amyloid fibrils at a neutral pH. (3) Polyphenols or vitamin A related compounds are found to inhibit the fibril formation of β-amyloid fibrils and to destabilize the preformed fibrils in vitro. (4) a direct thermodynamic analysis of amyloid fibril formation using isothermal titration calorimetry was develpoed. This investigation enables us to measure the heat capacity and enthalpy, and to estimate the stability and structural information on the conformational change of amyloidogenic proteins during fibril formation. As the conclusion of this study, remarkable advance on the clarification of the molecular mechanism of fibril formation in vitro was obtained. Furthermore, useful characteristics of amyloid fibril formation and dissociation for the application to nanotechnology were discovered.