Excitation Dynamics in Phycoerythrin 545: Modeling of Steady-State Spectra and Transient Absorption with Modified Redfield Theory

TitleExcitation Dynamics in Phycoerythrin 545: Modeling of Steady-State Spectra and Transient Absorption with Modified Redfield Theory
Publication TypeJournal Article
Year of Publication2010
AuthorsNovoderezhkin, VI, Doust AB, Curutchet C, Scholes GD, van Grondelle R
JournalBiophysical Journal
Volume99
Issue2
Pagination344 - 352
Date Published2010
ISBN Number0006-3495
Keywordselectronic-energy transfer, forster, Protein, resolution, spectroscopy
AbstractWe model the spectra and excitation dynamics in the phycobiliprotein antenna complex PE545 isolated from the unicellular photosynthetic cryptophyte algae Rhodomonas CS24. The excitonic couplings between the eight bilins are calculated using the CIS/6-31G method. The site energies are extracted from a simultaneous fit of the absorption, circular dichroism, fluorescence, and excitation anisotropy spectra together with the transient absorption kinetics using the modified Redfield approach. Quantitative fit of the data enables us to assign the eight exciton components of the spectra and build up the energy transfer picture including pathways and timescales of energy relaxation, thus allowing a visualization of excitation dynamics within the complex.