title: Time-dependent density-functional approach for biological chromophores: the case of the green fluorescent protein.
abstract: We performed first-principles calculations of the optical response of the green fluorescent protein (GFP) within a combined quantum-mechanical molecular-mechanics and time-dependent density-functional theory approach. The computed spectra are in excellent agreement with experiments assuming the presence of two, protonated and deprotonated, forms of the photoreceptor in a approximately 4:1 ratio, which supports the conformation model of photodynamics in GFP. Furthermore, we discuss charge transfer, isomerization, and environment effects. The present approach allows for systematic studies of excited-state electron-ion dynamics in biological systems.
authors.affiliation: Departamento de Física de Materiales, Facultad de Químicas, UPV/EHU, 20018 San Sebastián, Spain.
authors.forename: Miguel A L
authors.initials: MA
authors.lastname: Marques
authors.forename: Xabier
authors.initials: X
authors.lastname: López
authors.forename: Daniele
authors.initials: D
authors.lastname: Varsano
authors.forename: Alberto
authors.initials: A
authors.lastname: Castro
authors.forename: Angel
authors.initials: A
authors.lastname: Rubio
mesh_terms: D000838:Anions; D003198:Computer Simulation; D049452:Green Fluorescent Proteins; D007536:Isomerism; D008164:Luminescent Proteins / Q000737:chemistry*; D008958:Models, Molecular; D010777:Photochemistry; D011487:Protein Conformation; D011789:Quantum Theory
chemical_list: D000838:Anions; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins