Fig. 6
From: Plasmonic photocatalyst-like fluorescent proteins for generating reactive oxygen species
a 3D structure of a monomer of KillerRed obtained from X-ray crystallography (Reproduced from [85] with the permission of by John Wiley and Sons Inc.). Monomer A is shown with the backbone represented in gray and the chromophore in red. The cavity forming the channel is shown as the orange isomesh at 1 Å above the van der Walls radius and water molecules in the channel are depicted as the blue spheres. The cleft-like opening channel filled with water (oxygen) molecules is located in the β-barrel frame between β7 and β10 sheets. b Possible escape routes for molecular oxygen in the simulations (Reproduced from [86] with the permission of Royal Society of Chemistry). The chromophore is shown in red, the residues at the exits in blue, and other important residues along the pathways in pink. The escape pathways are highlighted by arrows (major channels in blue and minor channels in green). c, d Detection of O •‒2 photogenerated from KillerRed (Reproduced from [68] with the permission of Royal Society of Chemistry). c Light absorption (left panels) and emission (right panels) of KillerRed with and without the radical fluorescent probe TEMPO-9-ac (λex = 358 nm and λem = 440 nm). d Representative EPR spectrum of KillerRed with DMPO in a PBS solution under light irradiation at λex = 560 nm, supporting O •‒2 generation