Unveiling the excited state energy transfer pathways in peridinin-chlorophyll a-protein by ultrafast multi-pulse transient absorption spectroscopy

作者：Redeckas Kipras^*; Voiciuk Vladislava; Zigmantas Donatas; Hiller Roger G; Vengris Mikas

来源：Biochimica et Biophysica Acta-Bioenergetics, 2017, 1858(4): 297-307.

DOI：10.1016/j.bbabio.2017.01.014

• Peridinin-chlorophyll alpha-protein
• Pump-probe
• Pump-dump-probe
• Intramolecular charge transfer
• Excited state equilibrium
• Excitation energy transfer

Time-resolved multi-pulse methods were applied to investigate the excited state dynamics, the interstate couplings, and the excited state energy transfer pathways between the light-harvesting pigments in peridinin-chlorophyll a-protein (PCP). The utilized pump-dump-probe techniques are based on perturbation of the regular PCP energy transfer pathway. The PCP complexes were initially excited with an ultrashort pulse, resonant to the S-0 -> S-2 transition of the carotenoid peridinin. A portion of the peridinin-based emissive intramolecular charge transfer (ICT) state was then depopulated by applying an ultrashort NIR pulse that perturbed the interaction between S-1 and ICT states and the energy flow from the carotenoids to the chlorophylls. The presented data indicate that the peridinin S-1 and ICT states are spectrally distinct and coexist in an excited state equilibrium in the PCP complex. Moreover, numeric analysis of the experimental data asserts ICT -> Chl-a as the main energy transfer pathway in the photoexcited PCP systems.

• 出版日期2017-4