Mathew Manjumol, Aravindakumar Charuvila T, Aravind Usha K
Advanced Centre of Environmental Studies and Sustainable Development, Mahatma Gandhi University Kottayam-686 560 India.
School of Environmental Sciences, Inter University Instrumentation Centre, Mahatma Gandhi University Kottayam-686 560 India.
RSC Adv. 2020 Apr 24;10(28):16415-16421. doi: 10.1039/c9ra10655c. eCollection 2020 Apr 23.
The intriguing resemblances of amyloid fibrils and spider silk in protein aggregation diseases have instigated the exploration of identical structural features if any in their oligomeric pathways. The serpin group protein, ovalbumin, on defolding in HgCl shares commonness to the micellar pathway of spidroins for their aggregation in response to a pH trigger. The structural feature changes from monomer to worm like fibril with a shift in the primary protein pH to slightly acidic pH (4.5), and then proceeds through a secondary nucleation pathway to 'hillock' and 'hydra' like protofibrils rich in β-sheet and random coil conformers upon exposure to mercury. The findings are backed by atomic force microscopy, confocal Raman spectroscopy and fluorescence measurements. Unlocking such structural features can favorably assist in the design of therapeutics.
淀粉样纤维与蜘蛛丝在蛋白质聚集疾病中的有趣相似性,促使人们探索它们在寡聚途径中是否存在相同的结构特征。丝氨酸蛋白酶抑制剂家族蛋白卵清蛋白在HgCl中去折叠时,与蜘蛛丝蛋白的胶束途径具有共性,它们在pH触发下发生聚集。随着主要蛋白质pH值向微酸性pH(4.5)转变,结构特征从单体变为蠕虫状纤维,然后在接触汞后通过二次成核途径形成富含β-折叠和无规卷曲构象的“小丘”和“九头蛇”样原纤维。这些发现得到了原子力显微镜、共聚焦拉曼光谱和荧光测量的支持。揭示这些结构特征将有助于设计治疗方法。