A Multicolor Large Stokes Shift Fluorogen‐Activating RNA Aptamer with Cationic Chromophores. Issue 8 (11th January 2019)

• Record Type: Journal Article
• Authors: Steinmetzger, Christian; Palanisamy, Navaneethan; Gore, Kiran R.; Höbartner, Claudia
• Is Part Of: Chemistry. Volume 25:Issue 8(2019)
• Page Start: 1931
• Page End: 1935
• Publication Date: 2019-01-11
• Subjects: fluorescence -- Förster resonance energy transfer -- fluorescent proteins -- large Stokes shift -- RNA aptamers; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201805882
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Large Stokes shift (LSS) fluorescent proteins (FPs) exploit excited state proton transfer pathways to enable fluorescence emission from the phenolate intermediate of their internal 4‐hydroxybenzylidene imidazolone (HBI) chromophore. An RNA aptamer named Chili mimics LSS FPs by inducing highly Stokes‐shifted emission from several new green and red HBI analogues that are non‐fluorescent when free in solution. The ligands are bound by the RNA in their protonated phenol form and feature a cationic aromatic side chain for increased RNA affinity and reduced magnesium dependence. In combination with oxidative functionalization at the C2 position of the imidazolone, this strategy yielded DMHBO +, which binds to the Chili aptamer with a low‐nanomolar K D . Because of its highly red‐shifted fluorescence emission at 592 nm, the Chili–DMHBO + complex is an ideal fluorescence donor for Förster resonance energy transfer (FRET) to the rhodamine dye Atto 590 and will therefore find applications in FRET‐based analytical RNA systems. Abstract : "My shadow side so amplified." (Red Hot Chili Peppers): A large Stokes shift fluorogen‐activating RNA aptamer (LSS FLAP) named "Chili" strongly amplifies green or red fluorescence emission of otherwise non‐fluorescent, tightly bound cationic ligands upon excitation with blue light. Chili allows visualization of RNA and can be used in FRET sensors.