Table 2.
Rate constants and energy transfer efficiencies obtained from the ultrafast, time-resolved optical spectroscopic experiments on the PCP complexes reconstituted with various Chls
| PCP complex | kET2 (ps−1) | kIC2 (ps−1) | kET1 (ps−1) | kIC1 (ps−1) | ε (from fluorescence excitation), % | ε (from time-resolved absorption), % |
|---|---|---|---|---|---|---|
| Chl a | 10 ± 2.5 | 15 ± 1.5 | 0.34 ± 0.034 | 0.063 | 94 ± 2 | 91 ± 7 |
| Chl b | 10 ± 2.5 | 15 ± 1.5 | 0.17 ± 0.017 | 0.063 | 92 ± 2 | 84 ± 14 |
| Chl d | 13 ± 3.0 | 15 ± 1.5 | 0.59 ± 0.059 | 0.063 | 96 ± 3 | 95 ± 2 |
| aChl a | 11 ± 2.8 | 15 ± 1.5 | 0.45 ± 0.045 | 0.063 | 99 ± 1 | 93 ± 4 |
| BChl a | 10 ± 2.5 | 15 ± 1.5 | 2.22 ± 0.22 | 0.063 | ∼100 | 98 ± 2 |
kET2 and kET1 are the rate constants for energy transfer from the S2 and S1/ICT states of peridinin (Polívka et al 2005). kIC2 and kIC1 are the rate constants for internal conversion from S2 to S1/ICT and from S1/ICT to S0, respectively. kIC2 was obtained from fluorescence up-conversion measurement on the native PCP complex (Linden et al 2004). kIC1 was deduced from the efficiency and dynamics of energy transfer in the native MFPCP given in Ref. (Zigmantas et al 2002). kIC2 and kIC1 were assumed to be unchanged in all the PCP complexes. The peridinin-to-Chl energy transfer efficiency, ε, was obtained from steady-state fluorescence excitation experiments and from ultrafast, time-resolved absorption spectroscopic measurements at room temperature. The uncertainties in the values of ε from fluorescence excitation experiments were derived from the standard deviations obtained in the 450–515 nm wavelength range. The uncertainties in the values of ε from time-resolved absorption measurements were obtained by propagating the published errors in the dynamics
aChl a 3-acetyl-Chl a