title: Theoretical studies on the isomerization mechanism of the ortho-green fluorescent protein chromophore.
abstract: We present a systematic theoretical investigation on the overall ground state and excited-state isomerization reaction mechanism of ortho-green fluorescent protein chromophore (o-HBDI) using the density functional theory and the multireference methods. The calculated results and subsequent analysis suggest the possible isomerization mechanism for o-HBDI. By comparison with experimental observation and detailed analysis, it is concluded that as initiated by the excited-state intramolecular proton transfer reaction, the conical intersection between the ground state and the excited state along the C4-C5 single-bond rotational coordinate is responsible for the rapid deactivation of o-HBDI.
authors.affiliation: Division of Theoretical Chemistry & Biology, School of Biotechnology, Royal Institute of Technology, S-106 91, Stockholm, Sweden.
authors.forename: Yue-Jie
authors.initials: YJ
authors.lastname: Ai
authors.forename: Rong-Zhen
authors.initials: RZ
authors.lastname: Liao
authors.forename: Wei-Hai
authors.initials: WH
authors.lastname: Fang
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
mesh_terms: D049452:Green Fluorescent Proteins / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D007093:Imidazoles / Q000737:chemistry; D007536:Isomerism; D008958:Models, Molecular
chemical_list: C550727:4-(2-hydroxybenzylidene)-1,2-dimethyl-1H-imidazol-5(4H)-one; D007093:Imidazoles; D049452:Green Fluorescent Proteins