Variation of spectral, structural, and vibrational properties within the intrinsically fluorescent proteins family: A density functional study

We report an extensive (time-dependent) density functional study of the whole series of the chromophores within the Intrinsically Fluorescent Protein family, in the relevant conformations and protonation states. Over 30 structures are considered, including three newly discovered chromophores (zFP, Kaede, and the Orange variant of DsRed). Ab initio calculations on selected structures are also performed in order to assess the performances of TDDFT along the family. The use of a uniform scheme for all structures allows to establish relationships between the absorption energy and electrostatic, structural or vibrational properties of the chromophores.