School of Chemistry, University of Hyderabad, Hyderabad, India.
Biopolymers. 2019 Jul;110(7):e23255. doi: 10.1002/bip.23255. Epub 2019 Jan 11.
Although considerable information is available regarding protein-sodium dodecyl sulfate (SDS) interactions, it is still unclear as to how much SDS is needed to denature proteins. The role of protein charge and micellar surfactant concentration on amyloid fibrillation is also unclear. This study reports on equilibrium measurements of SDS interaction with six model proteins and analyzes the results to obtain a general understanding of conformational breakdown, reorganization and restructuring of secondary structure, and entry into the amyloid fibrillar state. Significantly, all of these responses are entirely resolved at much lower than the critical micellar concentration (CMC) of SDS. Electrostatic interaction of the dodecyl sulfate anion (DS ) with positive surface potential on the protein can completely unfold both secondary and tertiary structures, which is followed by protein chain restructuration to α-helices. All SDS-denatured proteins contain more α-helices than the corresponding native state. SDS interaction stochastically drives proteins to the aggregated fibrillar state.
尽管已经有大量关于蛋白质-十二烷基硫酸钠（SDS）相互作用的信息，但仍不清楚需要多少 SDS 才能使蛋白质变性。蛋白质电荷和胶束表面活性剂浓度对淀粉样纤维形成的作用也不清楚。本研究报告了 SDS 与六种模型蛋白质相互作用的平衡测量，并对结果进行了分析，以获得对构象分解、二级结构的重新组织和重构以及进入淀粉样纤维状态的总体理解。重要的是，所有这些反应都完全发生在低于 SDS 的临界胶束浓度（CMC）。十二烷基硫酸根阴离子（DS）与蛋白质上的正表面电势的静电相互作用可以完全展开二级和三级结构，随后是蛋白质链的重排为α-螺旋。所有 SDS 变性的蛋白质都比相应的天然状态含有更多的α-螺旋。SDS 相互作用随机地将蛋白质驱动到聚集的纤维状状态。
