Engineering fluorescent protein chromophores with an internal reference for high-fidelity ratiometric G4 imaging in living cells.

ABSTRACT: G-quadruplexes (G4s) are significant nucleic acid secondary structures formed by guanine-rich sequences. Many single-emission G4 fluorescent probes that are lit up by inhibiting intramolecular rotation have been reported. However, they are non-fluorescent unless structurally rigidified, making them sensitive to other intracellular crowding and confinement environments in the cell, like viscosity. Ratiometric measurements provide built-in self-calibration for signal correction, enabling more sensitive and reliable detection. Herein, we structurally modulate green fluorescent protein (GFP)-like chromophores by integrating the imidazolidinone scaffold of the GFP chromophore and coumarin 6H, obtaining a G4 responsive dual-emission chromophore, called NHCouI. The red emission signal of NHCouI c

SUBMITTER: Han JN 

PROVIDER: S-EPMC10155918 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature