Chen Xingwang, Pan Junlin, Nie Xiaomei, Bi Yege, Meng Jia, Wang Rui, Li Lu, Liu Dan, Cai Shanjun
Suzhou Medical College, Soochow University, Suzhou 215021, China.
Department of Ophthalmology, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, China.
ACS Omega. 2025 Aug 13;10(33):37674-37686. doi: 10.1021/acsomega.5c04236. eCollection 2025 Aug 26.
Transthyretin (TTR) G83R mutation can cause vitreous amyloidosis and severely impair vision. Further understanding of the effect of G83R mutation on the TTR structure and stability will help to understand its pathogenesis. This study investigated the thermodynamic and dynamic stabilities, as well as fibril formation, of TTR G83R and compared them with those of wild-type TTR and V30 M variants. Bioinformatics tools (NetSurfP 3.0, DynaMut2, and Desmond) were used to explore the effect of G83R on the TTR protein structural and dynamic stabilities. We explored the effect of G83R on TTR thermodynamic stability using urea-mediated resveratrol and tryptophan fluorescence. The effect of G83R affects TTR aggregation and fibril formation in acidic environments. Molecular dynamics simulation suggested that the G83R mutation reduces the dynamic stability of TTR by increasing the molecule's flexibility. Regarding thermodynamic stability, the quaternary and tertiary structural stabilities of TTR G83R are significantly lower than those of wild-type TTR but higher than those of TTR V30M. The fibril formation rate of TTR G83R under acidic conditions was between those of wild-type TTR and V30 M variants. In summary, the results from several different analyses in this study consistently demonstrate that the thermodynamic and dynamic stabilities of TTR G83R decrease. The G83R mutation makes TTR tetramers more susceptible to depolymerization and accelerates the formation of amyloid fibers.
转甲状腺素蛋白（TTR）的G83R突变可导致玻璃体淀粉样变性并严重损害视力。进一步了解G83R突变对TTR结构和稳定性的影响将有助于理解其发病机制。本研究调查了TTR G83R的热力学和动力学稳定性以及纤维形成情况，并将其与野生型TTR和V30M变体进行比较。使用生物信息学工具（NetSurfP 3.0、DynaMut2和Desmond）来探究G83R对TTR蛋白质结构和动力学稳定性的影响。我们使用尿素介导的白藜芦醇和色氨酸荧光来探究G83R对TTR热力学稳定性的影响。G83R的影响在酸性环境中会影响TTR聚集和纤维形成。分子动力学模拟表明，G83R突变通过增加分子的灵活性降低了TTR的动力学稳定性。关于热力学稳定性，TTR G83R的四级和三级结构稳定性显著低于野生型TTR，但高于TTR V30M。TTR G83R在酸性条件下的纤维形成速率介于野生型TTR和V30M变体之间。总之，本研究中几种不同分析的结果一致表明，TTR G83R的热力学和动力学稳定性降低。G83R突变使TTR四聚体更容易解聚，并加速淀粉样纤维的形成。
