Department of Chemistry, The University of Chicago, 5735 S. Ellis Avenue, Chicago, Illinois 60637, United States.
Department of Biochemistry and Molecular Biology, The University of Chicago, 929 E. 57th Street W225, Chicago, Illinois 60637, United States.
J Phys Chem Lett. 2023 Sep 14;14(36):8268-8276. doi: 10.1021/acs.jpclett.3c01257. Epub 2023 Sep 7.
Voltage-sensitive fluorescent dyes such as di-8-ANEPPS (di-8-aminonaphthylethylenepyridinium propylsulfonate) are powerful tools to study biological membranes. Its fluorescence is affected by changes in the membrane potential and other factors, requiring extensive calibration to extract meaningful quantitative results. The amphiphilic di-8-ANEPPS molecule is expected to bind at the membrane-solution interface. However, atomic-level information is sparse about its position and orientation in the membrane, especially in regards to how the latter dynamically fluctuates to affect the observed fluorescence. In the present work, molecular dynamics simulations of the ground and excited states of di-8-ANEPPS embedded in a DPPC membrane as represented by classical force fields were used to investigate how the fluorescence is affected by externally applied potential. The calculations reproduce the shifts in the wavelength of emission as a function of voltage that are observed experimentally, indicating that the approach can help better understand the various factors that can affect the fluorescence of membrane-bound dyes.
电压敏感荧光染料，如 di-8-ANEPPS（二-8-氨基萘基乙烯基吡啶丙磺酸酯），是研究生物膜的有力工具。其荧光受膜电位和其他因素变化的影响，需要广泛的校准才能提取有意义的定量结果。亲脂性的 di-8-ANEPPS 分子预计会结合在膜-溶液界面上。然而，关于其在膜中的位置和取向的原子级信息却很少，特别是关于后者如何动态波动来影响观察到的荧光的信息。在目前的工作中，使用经典力场来代表 DPPC 膜中的 di-8-ANEPPS 的基态和激发态的分子动力学模拟，研究了外部施加的电位如何影响荧光。该计算再现了实验中观察到的发射波长随电压变化的偏移，表明该方法可以帮助更好地理解可能影响膜结合染料荧光的各种因素。
