Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijng, 100190, China.
Photosynth Res. 2012 Mar;111(1-2):81-6. doi: 10.1007/s11120-011-9708-3. Epub 2011 Nov 15.
Energy transfer (ET) processes between chromophores in R-phycoerythrin (R-PE) from Polysiphonia urceolata were studied by use of ultrafast spectroscopic methods. Several primary ET pathways were elaborated. A fluorescence decay component with a time constant of several hundred picoseconds observed by streak camera is tentatively assigned to the reversible formation of exciton traps between α84 and β84 pigment pairs. In order to investigate much faster ET processes in R-PE, a noncollinear optical parametric amplifier based femtosecond time-resolved transient fluorescence spectrometer was employed. The results reveal that the ET between α84 and β84 pigment pair has a time constant of 1-2 ps; the energy migration between α84 and β84 pairs within the R-PE trimer has a time constant of 30-40 ps. We also demonstrated an ET process from phycourobilin to phycoerythrobilin with a time constant as fast as 2.5-3.0 ps, which was directly observed in fluorescence kinetics by selective excitation of the phycourobilin molecules acting as the energy donor.
使用超快光谱方法研究了从 Polysiphonia urceolata 中提取的藻红蛋白（R-PE）中发色团之间的能量转移（ET）过程。阐述了几种主要的 ET 途径。通过条纹相机观察到的具有数百皮秒时间常数的荧光衰减分量，被暂时分配给α84 和β84 色素对之间的激子陷阱的可逆形成。为了研究 R-PE 中更快的 ET 过程，使用了基于非共线光参量放大器的飞秒时间分辨瞬态荧光光谱仪。结果表明，α84 和β84 色素对之间的 ET 具有 1-2 ps 的时间常数；R-PE 三聚体中α84 和β84 对之间的能量迁移具有 30-40 ps 的时间常数。我们还证明了从藻蓝蛋白到藻红蛋白的 ET 过程具有与直接观察到的荧光动力学中作为能量供体的藻蓝蛋白分子的选择性激发一样快的时间常数 2.5-3.0 ps。
