title: Energy transfer dynamics in light-harvesting assemblies templated by the tobacco mosaic virus coat protein.
abstract: Picosecond time-resolved fluorescence spectroscopy was used to characterize energy transfer between chromophores displayed on a rod assembly of tobacco mosaic virus coat protein. The incorporation of donor chromophores with broad and overlapping absorption and emission spectra creates an "antenna" with a large absorption cross section, which can convey excitation energy over large distances before transfer to an acceptor chromophore. The possibility for both donor-to-donor and donor-to-acceptor transfer results in complex kinetic behavior at any single wavelength. Thus, to describe the various pathways of energy transfer within this system accurately, a global lifetime analysis was performed to obtain decay associated spectra. We found the energy transfer from donor to acceptor chromophores occurs in 187 ps with an efficiency of 36%. A faster decay component of 70 ps was also observed from global lifetime analysis and is attributed to donor-to-donor transfer. Although more efficient three-chromophore systems have been demonstrated, a two-chromophore system was studied here to facilitate analysis.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
authors.forename: Ying-Zhong
authors.initials: YZ
authors.lastname: Ma
authors.forename: Rebekah A
authors.initials: RA
authors.lastname: Miller
authors.forename: Graham R
authors.initials: GR
authors.lastname: Fleming
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Francis
mesh_terms: D036022:Capsid Proteins / Q000737:chemistry* / Q000528:radiation effects; D004735:Energy Transfer / Q000528:radiation effects; D005456:Fluorescent Dyes / Q000737:chemistry / Q000528:radiation effects; D008027:Light; D008954:Models, Biological; D008958:Models, Molecular; D015394:Molecular Structure; D011994:Recombinant Proteins / Q000737:chemistry / Q000528:radiation effects; D013050:Spectrometry, Fluorescence / Q000379:methods; D013997:Time Factors; D014027:Tobacco Mosaic Virus / Q000737:chemistry*
chemical_list: D036022:Capsid Proteins; D005456:Fluorescent Dyes; D011994:Recombinant Proteins