01848nas a2200169   4500008004100000022001400041245012200055210006900177260007100246300001400317490000800331520115300339100001601492700002301508700002101531856012601552       2016                        eng d  a1520-610600aEffect of solvation on electron detachment and excitation energies of a green fluorescent protein chromophore variant0 aEffect of solvation on electron detachment and excitation energi  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a4410-44200 v1203 a<p>Hybrid quantum mechanics/molecular mechanics (QM/MM) is applied to the fluorinated green fluorescent protein (GFP) chromophore (DFHBDI) in its deprotonated form to understand the solvatochromic shifts in its vertical detachment energy (VDE) and vertical excitation energy (VEE). This variant of the GFP chromophore becomes fluorescent in an RNA environment and has a wide range of applications in biomedical and biochemical fields. From microsolvation studies, we benchmark (with respect to full QM) the accuracy of our QM/MM calculations with effective fragment potential (EFP) as the MM method of choice. We show that while the solvatochromic shift in the VEE is minimal (0.1 eV blue shift) and its polarization component is only 0.03 eV, the effect of the solvent on the VDE is quite large (3.85 eV). We also show by accurate calculations on the solvatochromic shift of the VDE that polarization accounts for similar to 0.23 eV and therefore cannot be neglected. The effect of the counterions on the VDE of the deprotonated chromophore in solvation is studied in detail, and a charge-smearing scheme is suggested for charged chromophores.</p>1 aBose, Samik1 aChakrabarty, Suman1 aGhosh, Debashree  uhttps://library.ncl.res.in/content/effect-solvation-electron-detachment-and-excitation-energies-green-fluorescent-protein