Energy transfer processes in the isolated core antenna complexes CP43 and CP47 of photosystem II

详细信息    查看全文

• 作者：Anna Paola Casazza ; Malwina Szczepaniak ; Marc G. Mü ; ller ; Giuseppe Zucchelli ; Alfred R. Holzwarth
• 关键词：antenna complexes ; photosystem II ; energy transfer ; fluorescence kinetics ; femtosecond absorption ; photosynthesis
• 刊名：Biochimica et Biophysica Acta (BBA)/Bioenergetics
• 出版年：2010
• 出版时间：September 2010
• 年：2010
• 卷：1797
• 期：9
• 页码：1606-1616
• 全文大小：2066 K

文摘

The energy equilibration and transfer processes in the isolated core antenna complexes CP43 and CP47 of photosystem II have been studied by steady-state and ultrafast (femto- to nanosecond) time-resolved spectroscopy at room temperature. The annihilation-free femtosecond absorption data can be described by surprisingly simple sequential kinetic models, in which the excitation energy transfer between blue and red states in both antenna complexes is dominated by sub-picosecond processes and is completed in less than 2 ps. The slowest energy transfer steps with lifetimes in the range of 1–2 ps are assigned to transfer steps between the chlorophyll layers located on the stromal and lumenal sides. We conclude that these ultrafast intra-antenna energy transfer steps do not represent a bottleneck in the rate of the primary processes in intact photosystem II. Since the experimental energy equilibration rates are up to a factor of 3–5 higher than concluded previously, our results challenge the conclusions drawn from theoretical modeling.