title: Computational strategy for tuning spectral properties of red fluorescent proteins.
abstract: Computational methods of quantum chemistry are used to characterize structures and vertical excitation energies of the S(0)-S(1) optical transitions in the chromophore binding pockets of the red fluorescent proteins DsRed and of its artificial mutant mCherry. As previously shown, optimizing the equilibrium geometry configurations with B3LYP density functional theory, followed by ZINDO calculations of the electronic excitations, yields positions of the optical bands in good agreement with experimental data. These large scale quantum calculations elucidate the role of the hydrogen bonded network as well as point mutations in the absorption spectra of the DsRed and mCherry proteins. The effect of an external electric field applied to the fluorescent protein chromophores is examined and shows that such fields may result in large shifts in spectral bands. These strategies can be applied for rational design of the fluorescent proteins by site-directed mutagenesis.
authors.affiliation: Advanced Biomedical Computing Center, Information Systems Program, SAIC- Frederick Inc., NCI-Frederick, MD 21702-1201, USA. topoli@mail.nih.gov
authors.forename: I
authors.initials: I
authors.lastname: Topol
authors.forename: J
authors.initials: J
authors.lastname: Collins
authors.forename: A
authors.initials: A
authors.lastname: Savitsky
authors.forename: A
authors.initials: A
authors.lastname: Nemukhin
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D004560:Electricity; D008164:Luminescent Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D017354:Point Mutation; D011487:Protein Conformation; D011789:Quantum Theory; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein