Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow, 119991, Russian Federation.
Photochem Photobiol Sci. 2019 Jan 1;18(1):177-189. doi: 10.1039/c8pp00361k. Epub 2018 Nov 7.
The iLOV protein is a promising member of the class of flavin mononucleotide (FMN) based fluorescent proteins (FbFPs). It is becoming a popular tool for bioanalytical applications and bioimaging as a competitor of the well-known green fluorescent protein and its analogues. The main limitation of FbFPs is that all the members have close values of their absorption and emission band maxima. Therefore the upcoming challenge is to introduce novel variants of FbFPs to extend their color palette. We report the results of computational studies of iLOV variants, introducing point mutations and chromophore analogues. We found that point mutations of the apoprotein and substitution of FMN with either 8-amino-FMN or 8-methylamino-FMN lead to the red shift of emission bands up to 100 nm. Substitution with 1-deaza-FMN and the point mutations of the apoprotein result in a set of novel fluorescent proteins with emission bands in the "transparent" window where light readily penetrates through mammalian tissues. Newly suggested FbFPs can be used for multicolor imaging and also as components of FRET pairs.
iLOV 蛋白是一类黄素单核苷酸（FMN）基荧光蛋白（FbFPs）中很有前途的成员。它作为著名的绿色荧光蛋白及其类似物的竞争对手，正在成为生物分析应用和生物成像的热门工具。FbFPs 的主要限制是所有成员的吸收和发射带最大值都接近。因此，即将面临的挑战是引入新型 FbFP 变体以扩展其调色板。我们报告了对 iLOV 变体进行计算研究的结果，引入了点突变和发色团类似物。我们发现，apo 蛋白的点突变以及用 8-氨基-FMN 或 8-甲基氨基-FMN 替代 FMN 会导致发射带红移高达 100nm。用 1-脱氮-FMN 替代和 apo 蛋白的点突变导致一组新型荧光蛋白的发射带在“透明”窗口中，光可以轻松穿透哺乳动物组织。新提出的 FbFPs 可用于多色成像，也可用作 FRET 对的组成部分。
