title: A polarizable embedding DFT study of one-photon absorption in fluorescent proteins.
abstract: A theoretical study of the one-photon absorption of five fluorescent proteins (FPs) is presented. The absorption properties are calculated using a polarizable embedding approach combined with density functional theory (PE-DFT) on the wild-type green fluorescent protein (wtGFP) and several of its mutants (BFP, eGFP, YFP and eCFP). The observed trends in excitation energies among the FPs are reproduced by our approach when performing calculations directly on the crystal structures or when using structures extracted from molecular dynamics simulations. However, in the former case, QM/MM geometry optimization of the chromophores within a frozen protein environment is needed in order to reproduce the experimental trends. An explicit account of polarization in the force field is not needed to yield the correct trend between the different FPs, but it is necessary for reproducing the experimentally observed red shift from vacuum to protein. This is the first computational study of a range of fluorescent proteins using a polarizable embedding potential.
authors: Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway.
authors: Maarten T P
authors: MT
authors: Beerepoot
authors: Arnfinn Hykkerud
authors: AH
authors: Steindal
authors: Jacob
authors: J
authors: Kongsted
authors: Bjørn Olav
authors: BO
authors: Brandsdal
authors: Luca
authors: L
authors: Frediani
authors: Kenneth
authors: K
authors: Ruud
authors: Jógvan Magnus Haugaard
authors: JM
authors: Olsen
mesh_terms: D049452:Green Fluorescent Proteins / Q000737:chemistry* / Q000235:genetics; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D009154:Mutation; D011522:Protons; D011789:Quantum Theory
chemical_list: D011522:Protons; D049452:Green Fluorescent Proteins