The excitation energy transfer between β-Car and Chla molecules in PS II core antenna complexes CP43 and CP47

The excitation energy transfer efficiency between β-Car and Chla molecules in purified CP43 and CP47 was calculated by comparing absorption and fluorescence excitation after normalization at 550 nm, CP43 had an energy transfer efficiency of 29.1% while the CP47 had an energy transfer efficiency of 62.8%, proving that excitation energy was transferred between β-Car and Chla molecules in CP43 and CP47 at normal conditions. The excitation energy transfer between β-Car and Chla molecules in CP43 and CP47 may occur through the “Dexter” mechanism and the distance between these two kinds of pigments should be less than 1 nm. In addition, the results were also used to discuss the conformational relationship between β-Car and Chla molecules in CP43 and CP47.