Low energy states of cyanobacterial photosystem I antenna complexes

Monomeric and trimeric pigment-protein antenna complexes of photosystem I (PSI) isolated from cyanobacteria Arthrospira platensis were studied both experimentally and theoretically. An exciton model was proposed to explain one of PSI spectral features: low energy states, whose energies are red-shifted in comparison with those of PSI reaction center. We present results of the modeling of linear and transient absorption spectroscopy.