A new twist in the photophysics of the GFP chromophore: a volume-conserving molecular torsion couple.

ABSTRACT: The simple structure of the chromophore of the green fluorescent protein (GFP), a phenol and an imidazolone ring linked by a methyne bridge, supports an exceptionally diverse range of excited state phenomena. Here we describe experimentally and theoretically the photochemistry of a novel sterically crowded nonplanar derivative of the GFP chromophore. It undergoes an excited state isomerization reaction accompanied by an exceptionally fast (sub 100 fs) excited state decay. The decay dynamics are essentially independent of solvent polarity and viscosity. Excited state structural dynamics are probed by high level quantum chemical calculations revealing that the fast decay is due to a conical intersection characterized by a twist of the rings and pyramidalization of the methyne bridge carbon.

SUBMITTER: Conyard J 

PROVIDER: S-EPMC5892128 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature