Blue fluorescent dye-protein complexes based on fluorogenic cyanine dyes and single chain antibody fragments
作者:Kimberly J. Zanotti、Gloria L. Silva、Yehuda Creeger、Kelly L. Robertson、Alan S. Waggoner、Peter B. Berget、Bruce A. Armitage
DOI:10.1039/c0ob00444h
日期:——
Fluoromodules are complexes formed upon the noncovalent binding of a fluorogenic dye to its cognate biomolecular partner, which significantly enhances the fluorescence quantum yield of the dye. Previously, several single-chain, variable fragment (scFv) antibodies were selected from a yeast cell surface-displayed library that activated fluorescence from a family of unsymmetrical cyanine dyes covering much of the visible and near-IR spectrum. The current work expands our repertoire of genetically encodable scFv-dye pairs by selecting and characterizing a group of scFvs that activate fluorogenic violet-absorbing, blue-fluorescing cyanine dyes, based on oxazole and thiazole heterocycles. The dye binds to both yeast cell surface-displayed and soluble scFvs with low nanomolar Kd values. These dye-protein fluoromodules exhibit high quantum yields, approaching unity for the brightest system. The promiscuity of these scFvs with other fluorogenic cyanine dyes was also examined. Fluorescence microscopy demonstrates that the yeast cell surface-displayed scFvs can be used for multicolor imaging. The prevalence of 405 nm lasers on confocal imaging and flow cytometry systems make these new reagents potentially valuable for cell biological studies.
氟模块是一类由荧光素与其相应生物分子伙伴之间非共价结合形成的复合物,显著增强了染料的荧光量子产率。先前,从酵母细胞表面展示文库中筛选出几种单链可变片段(scFv)抗体,它们能激活一系列覆盖大部分可见光和近红外光谱的不对称菁染料的荧光。当前工作通过筛选和表征一组激活吸收紫外光、发射蓝光的以噁唑和噻唑杂环为基础的菁染料的scFv,拓展了我们可遗传编码的scFv-染料配对组合。该染料与酵母细胞表面展示的以及可溶性scFv结合,其解离常数Kd值在低纳摩尔级别。这些染料-蛋白质氟模块显示出高量子产率,最亮系统的量子产率接近于一。此外,还考察了这些scFv与其他荧光菁染料的结合能力。荧光显微镜显示,酵母细胞表面展示的scFv可用于多色成像。由于405纳米激光在共聚焦成像和流式细胞仪系统中的普及,这些新型试剂可能对细胞生物学研究具有潜在价值。