Kulkarni Rishikesh U, Yin Hang, Pourmandi Narges, James Feroz, Adil Maroof M, Schaffer David V, Wang Yi, Miller Evan W
Shenzhen Research Institute and Department of Physics, The Chinese University of Hong Kong , Shatin, New Territories, Hong Kong.
ACS Chem Biol. 2017 Feb 17;12(2):407-413. doi: 10.1021/acschembio.6b00981. Epub 2016 Dec 22.
Voltage imaging with fluorescent dyes offers promise for interrogating the complex roles of membrane potential in coordinating the activity of neurons in the brain. Yet, low sensitivity often limits the broad applicability of optical voltage indicators. In this paper, we use molecular dynamics (MD) simulations to guide the design of new, ultrasensitive fluorescent voltage indicators that use photoinduced electron transfer (PeT) as a voltage-sensing switch. MD simulations predict an approximately 16% increase in voltage sensitivity resulting purely from improved alignment of dye with the membrane. We confirm this theoretical finding by synthesizing 9 new voltage-sensitive (VoltageFluor, or VF) dyes and establishing that all of them display the expected improvement of approximately 19%. This synergistic outworking of theory and experiment enabled computational and theoretical estimation of VF dye orientation in lipid bilayers and has yielded the most sensitive PeT-based VF dye to date. We use this new voltage indicator to monitor voltage spikes in neurons from rat hippocampus and human pluripotent-stem-cell-derived dopaminergic neurons.
使用荧光染料进行电压成像为探究膜电位在协调大脑神经元活动中的复杂作用提供了希望。然而，低灵敏度常常限制了光学电压指示剂的广泛应用。在本文中，我们使用分子动力学（MD）模拟来指导新型超灵敏荧光电压指示剂的设计，这些指示剂利用光致电子转移（PeT）作为电压传感开关。MD模拟预测，仅由于染料与膜的排列改善，电压灵敏度将提高约16%。我们通过合成9种新的电压敏感（VoltageFluor，或VF）染料并确定它们都显示出约19%的预期改善，证实了这一理论发现。理论与实验的这种协同作用使得能够对脂质双层中VF染料的取向进行计算和理论估计，并产生了迄今为止最灵敏的基于PeT的VF染料。我们使用这种新的电压指示剂来监测大鼠海马体神经元和人类多能干细胞衍生的多巴胺能神经元中的电压尖峰。
