北京大学Peng Zou团队报道了视紫红质生物正交工程激活活神经元的远红外混合电压指示剂。相关研究成果于2021年4月15日发表在国际顶尖学术期刊《自然—化学》。

膜电位是细胞信号传导的一个重要方面，并由一系列离子选择泵和通道动态调节。荧光电压指示器能够以高空间分辨率无创光学记录细胞膜电位。

该文中，研究人员报道了一种明亮而灵敏的混合电压指示剂（HVI），其荧光强度通过电致变色共振能量转移对膜电位的变化敏感。酶介导的探针的位点特异性掺入和随后逆电子需求Diels-Alder环加成，被用于创建具有混合染料-蛋白质结构的增强电压感应的视紫红质。

最敏感的指标HVI-Cy3显示高电压敏感性（每100mV 39%ΔF/F0）和毫秒反应动力学，能够在大量神经元群体中以400赫兹的采样率在10分钟内光学记录动作电位。远红外指示剂HVI-Cy5可与光生致动器和绿色/红色荧光指示剂配对对神经元电生理进行全光研究。

附：英文原文

Title: A far-red hybrid voltage indicator enabled by bioorthogonal engineering of rhodopsin on live neurons

Author: Shuzhang Liu, Chang Lin, Yongxian Xu, Huixin Luo, Luxin Peng, Xiangmei Zeng, Huangtao Zheng, Peng R. Chen, Peng Zou

Issue&Volume: 2021-04-15

Abstract: Membrane potential is a key aspect of cellular signalling and is dynamically regulated by an array of ion-selective pumps and channels. Fluorescent voltage indicators enable non-invasive optical recording of the cellular membrane potential with high spatial resolution. Here, we report a palette of bright and sensitive hybrid voltage indicators (HVIs) with fluorescence intensities sensitive to changes in membrane potential via electrochromic Frster resonance energy transfer. Enzyme-mediated site-specific incorporation of a probe, followed by an inverse-electron-demand Diels–Alder cycloaddition, was used to create enhanced voltage-sensing rhodopsins with hybrid dye–protein architectures. The most sensitive indicator, HVI-Cy3, displays high voltage sensitivity (39% ΔF/F0 per 100mV) and millisecond response kinetics, enabling optical recording of action potentials at a sampling rate of 400Hz over 10min across a large neuronal population. The far-red indicator HVI-Cy5 could be paired with optogenetic actuators and green/red-emitting fluorescent indicators, allowing an all-optical investigation of neuronal electrophysiology.

DOI: 10.1038/s41557-021-00641-1

Source: https://www.nature.com/articles/s41557-021-00641-1