Identification of chlorophyll molecules in peripheral light harvesting complex LHC II

Abstract

Chlorophyll site excitation energies of the peripheral plant light-harvesting complex (LHC-II) have been determined by simulating the steady-state absorption and circular dichroism spectra and using new structural data. By applying the genetic algorithm search procedure it has been found that the fit to circular dichroism spectra is critical in narrowing the space of possible solutions. The obtained chlorophyll energy assignment has been verified by the Monte Carlo simulations of the excitation annihilation kinetics. It suggests that the chlorophyll a dimers a611-a612, a613-a614, and a602-a603 constitute the sites for the energy migration across the peripheral plant light-harvesting antenna.