Energy transfer kinetics of phycoerythrocyanin trimer from cyanobacteriumAnabaena variabilis (II).

The excitation energy transfer processes in trimeric PEC have been studied by using steady-state and time-resolved fluorescence spectra techniques in detail. The results indicate that the energy transfer processes should take place between alpha(84)-PVB and beta(84)-or beta(155)-PCB chromophores with the time constants 34.7 ps and 175-200 ps individually; in contrast with monomeric PEC, from time-resolved fluorescence anisotropic spectrum technique, the decay constant of 45 ps which was assigned to the energy transfer time among three beta(84)-PCB chromophores was observed and the energy levels of beta(84)-and/or beta(155)-PCB chromophores were confirmed to turn over in trimeric PEC.