Singlet-ezcitation energy transfer among carotenoids in the HL-LH2 complez from Rhodopseudomonas palustris
The structure of peripheral light harvesting complex (LH2) from photosynthetic bacterium Rhodopseudomonas(Rps.) palustris cultured at high-light(HL) is very complicated, which includes five kinds of carotenoids(Cars) molecules in one unit. Femtosecond time-resolved absorption spectroscopy has been used to study the process of excited-state energy transfer(EET) among Cars in LH2 excited by femtosecond laser pulse at different wavelength. The characteristic spectra of singlet (Sn) and triplet (T1) excitation Cars were observed in visible spectral region. The results suggest that the singlet EET processes may occur from Cars with shorter conjugation length(n) to that with longer conjugation length besides excitation energy internal conversion. These complicated excitation energy equilibrium in the HL-LH2 from Rps. palustris fulfills within 6 ps. It might imply that the coexistence of many Cars is helpful for Cars serving as photoprotection.
light-harvesting antenna carotenoid ezcited-state energy transfer time-resolved spectra photoprotection
Xiao-hui Zhao Rong-xiang Zhang Xiao-dong Tian Guang Li Lian-shui Zhang Xiao-ting Li
College of Physics Science & Technology, Hebei University, Baoding 071002, China College of Quality & Technical Supervision, Hebei University, Baoding 071002, China
国际会议
上海
英文
4620-4624
2008-05-16（万方平台首次上网日期，不代表论文的发表时间）