Comparative Studies of the Fluorescence Properties of Microbial Rhodopsins: Spontaneous Emission Versus Photointermediate Fluorescence
Comparative Studies of the Fluorescence Properties of Microbial Rhodopsins: Spontaneous Emission Versus Photointermediate Fluorescence
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DOI：
10.1021/acs.jpcb.0c06560
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发表时间：
2020-08-27
影响因子：
3.3
通讯作者：
Sudo, Yuki
中科院分区：
文献类型：
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作者：
Kojima, Keiichi;Kurihara, Rika;Sudo, Yuki
视紫红质是一种与视网膜发色团结合的七跨膜感光蛋白，被用作遗传编码电压指示剂（GEVI）。到目前为止，尽管其低荧光强度，但古视紫红质-3（AR 3）已成功地用作GEVI。我们对15种微生物视紫红质进行了比较和定量荧光分析，以探索这些高荧光分子并阐明其荧光机制。这些视紫红质在小鼠海马神经元中显示出宽范围的荧光强度。其中一些，GR，HwBR，IaNaR，MR和NpHR，显示出与AR 3相当或更高的荧光强度，表明它们具有GEVI的潜力。神经元中的荧光强度与明亮的荧光光中间体如Q-中间体的荧光强度相关（R = 0.75），表明神经元中的荧光来源于光中间体的荧光。我们的研究结果为生产下一代基于视紫红质的GEVI提供了关键的一步。
Rhodopsins are seven-transmembrane photoreceptor proteins that bind to the retinal chromophore and have been utilized as a genetically encoded voltage indicator (GEVI). So far, archaerhodopsin-3 (AR3) has been successfully used as a GEVI, despite its low fluorescence intensity. We performed comparative and quantitative fluorescence analyses of 15 microbial rhodopsins to explore these highly fluorescent molecules and to clarify their fluorescence mechanism. These rhodopsins showed a wide range of fluorescence intensities in mouse hippocampal neurons. Some of them, GR, HwBR, IaNaR, MR, and NpHR, showed fluorescence intensities comparable with or higher than that of AR3, suggesting their potential for GEVIs. The fluorescence intensity in neurons correlated with that of the bright fluorescent photointermediate such as a Q-intermediate (R = 0.75), suggesting that the fluorescence in neurons originates from the fluorescence of the photointermediate. Our findings provide a crucial step for producing next-generation rhodopsin-based GEVIs.