In vitro selection of dye-fluorescence-enhancing peptide aptamer by cDNA display.

Although Green Fluorescent Protein (GFP) is useful and most widely used, steric hindrance due to its size and the time required for chromophore formation are complications. However, it is difficult to form chromophores with peptides to reduce the molecular weight. Therefore, we focused on peptides that can become fluorescent by binding to dyes. In this study, a novel dye-fluorescence-enhancing peptide aptamer was selected by the cDNA display method, which was confirmed by the yeast surface display method. This peptide aptamer binds to the non-fluorescent dye QSY®9 and enhances its fluorescence by preventing rotation of its benzene sulfone group. The method described in this paper should enable the development of new cell imaging methods using non-fluorescent dyes and peptides.