Structural Flexibility and Disassembly Kinetics of Single Ferritins Using Optical Nanotweezers
Structural Flexibility and Disassembly Kinetics of Single Ferritins Using Optical Nanotweezers
复制标题
DOI：
10.1101/2023.09.22.558948
复制
发表时间：
2024-01
期刊：
影响因子：
--
通讯作者：
Arman Yousefi;Ze-yuan Zheng;Saaman Zargarbashi;Mahya Assadipapari;Graham J. Hickman;Christopher D. J. Parmenter;Gabriel Sanderson;Dominic Craske;Lei Xu;Mohsen Rahmani-;Cuifeng Ying
中科院分区：
文献类型：
--
作者：
Arman Yousefi;Ze-yuan Zheng;Saaman Zargarbashi;Mahya Assadipapari;Graham J. Hickman;Christopher D. J. Parmenter;Gabriel Sanderson;Dominic Craske;Lei Xu;Mohsen Rahmani-;Cuifeng Ying
铁蛋白是由24个亚基组成的球形蛋白质外壳，通过其通道作为一种有效的铁储存和释放系统。了解各种化学物质如何影响铁蛋白的结构行为对于解开包括人类在内的生物体中与铁相关的疾病的起源至关重要。特别是，化学品对铁蛋白的动力学和铁释放的影响几乎没有在单一蛋白质水平上探索。在这里，通过采用双纳米孔（DNH）结构的光学纳米钳，我们研究了抗坏血酸（还原剂）和pH值对铁蛋白构象动力学的影响。随着抗坏血酸浓度的接近饱和，铁蛋白的动态增加。在pH 2.0的铁蛋白表现出显着的结构波动，并最终经历了逐步拆卸成片段。这项工作，第一次，跟踪单一铁蛋白在溶液中的拆卸路径和动力学。我们确定了四个关键片段在其拆卸过程中，这是22聚体，12聚体，四聚体，和二聚体亚基。此外，我们提出了第一个单分子证据的合作拆卸铁蛋白。探究铁蛋白对不同化学物质的结构变化对于理解它们在铁代谢中的作用具有重要意义，从而促进相关疾病的医学治疗的进一步发展。
Ferritin, a spherical protein shell assembled from 24 subunits, functions as an efficient iron storage and release system through its channels. Understanding how various chemicals affect the structural behaviour of ferritin is crucial for unravelling the origins of iron-related diseases in living organisms including humans. In particular, the influence of chemicals on ferritin’s dynamics and iron release is barely explored at the single-protein level. Here, by employing optical nanotweezers using double nanohole (DNH) structures, we examined the effect of ascorbic acid (reducing reagent) and pH on ferritin’s conformational dynamics. The dynamics of ferritin increased as the concentration of ascorbic acid approached saturation. At pH 2.0 ferritin exhibited significant structural fluctuations and eventually underwent a stepwise disassembly into fragments. This work, for the first time, tracked the disassembly pathway and kinetics of single ferritins in solution. We identified four critical fragments during its disassembly pathway, which are 22-mer, 12-mer, tetramer, and dimer subunits. Moreover, we presented the first single-molecule evidence of the cooperative disassembly of ferritin. Interrogating ferritin’s structural change in response to different chemicals holds importance for understanding their roles in iron metabolism, hence facilitating further development of medical treatments for the associated diseases.