Kinetic fluorescence spectral analysis of core antennas CP43 and CP47 of photosystem II with ultrafast time-resolved technology

Ultrafast time-resolved fluorescence experiments have been performed with core antennas CP43 and CP47 of PS II. Their dynamic fluorescence spectra were obtained with excitation wavelength 514.5 mn. For CP43, the emission spectrum was found to be from 640 to 780 nm with a peak at similar to 680 ran and the lifetime of fluorescence was 3.54 ns. For CP47, the emission spectrum was from 630 to 775 run with a peak at similar to 691 nm and the fluorescence lifetime was 3.22 ns. The fluorescence emission efficiencies of Chl a in CP43 and CP47 were calculated to be approximately 38.3% and 40.6%, respectively. The energy transfer from beta -Car to Chl a in CP43 and CP47 was discussed. The rates of energy transfer from beta -Car to Chl a were measured to be about 9.6 x 10(11) s(-1) and 1.3 x 10(12) s(-1) and energy transfer efficiencies 47.5% and 66.5% respectively. The edge-edge distances between beta -Car and Chl a in CP43 and CP47 were estimated to be similar to 0.110 nm and similar to 0.085 nm respectively.