Kuo Chun-Tien, Chen Yi-Lin, Hsu Wei-Tse, How Su-Chun, Cheng Yu-Hong, Hsueh Shu-Shun, Liu Hwai-Shen, Lin Ta-Hsien, Wu Josephine W, Wang Steven S-S
Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan.
Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei 102, Taiwan; Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 102, Taiwan.
Int J Biol Macromol. 2017 May;98:159-168. doi: 10.1016/j.ijbiomac.2017.01.110. Epub 2017 Jan 27.
Formation of amyloid fibrils has been associated with at least 30 different protein aggregation diseases. The 129-residue polypeptide hen lysozyme, which is structurally homologous to human lysozyme, has been demonstrated to exhibit amyloid fibril-forming propensity in vitro. This study is aimed at exploring the influence of erythrosine B on the in vitro amyloid fibril formation of hen lysozyme at pH 2.0 and 55°C using ThT binding assay, transmission electron microscopy, far-UV circular dichroism absorption spectroscopy, 1-anilinonaphthalene-8-sulfonic acid fluorescence spectroscopy, and synchronous fluorescence study. We found that lysozyme fibrillogenesis was dose-dependently suppressed by erythrosine B. In addition, our far-UV CD and ANS fluorescence data showed that, as compared with the untreated lysozyme control, the α-to-ß transition and exposure of hydrophobic clusters in lysozyme were reduced upon treatment with erythrosine B. Moreover, it could be inferred that the binding of erythrosine B occurred in the vicinity of the tryptophan residues. Finally, molecular docking and molecular dynamics simulations were further employed to gain some insights into the possible binding site(s) and interactions between lysozyme and erythrosine B. We believe the results obtained here may contribute to the development of potential strategies/approaches for the suppression of amyloid fibrillogenesis, which is implicated in amyloid pathology.
淀粉样纤维的形成与至少30种不同的蛋白质聚集疾病有关。129个残基的多肽鸡溶菌酶在结构上与人溶菌酶同源，已被证明在体外具有形成淀粉样纤维的倾向。本研究旨在利用硫黄素T结合试验、透射电子显微镜、远紫外圆二色吸收光谱、1-苯胺基萘-8-磺酸荧光光谱和同步荧光研究，探索赤藓红B在pH 2.0和55°C条件下对鸡溶菌酶体外淀粉样纤维形成的影响。我们发现赤藓红B对溶菌酶的纤维形成有剂量依赖性抑制作用。此外，我们的远紫外圆二色光谱和ANS荧光数据表明，与未处理的溶菌酶对照相比，用赤藓红B处理后，溶菌酶中的α向β转变以及疏水簇的暴露减少。此外，可以推断赤藓红B的结合发生在色氨酸残基附近。最后，进一步采用分子对接和分子动力学模拟来深入了解溶菌酶与赤藓红B之间可能的结合位点和相互作用。我们相信这里获得的结果可能有助于开发抑制淀粉样纤维形成的潜在策略/方法，这与淀粉样病变有关。
