Science. 1985 Jan 25;227(4685):419-23. doi: 10.1126/science.227.4685.419.
A broadly tunable picosecond laser source and an ultrafast streak camera were used to measure temporally and spectrally resolved emission from intact phycobilisomes and from individual phycobiliproteins as a function of excitation wavelength. Both wild-type and mutant phycobilisomes of the unicellular cyanobacterium Synechocystis 6701 were examined, as well as two biliproteins, R-phycoerythrin (240 kilodaltons, 34 bilins) and allophycocyanin (100 kilodaltons, 6 bilins). Measurements of intact phycobilisomes with known structural differences showed that the addition of an average of 1.6 phycoerythrin disks in the phycobilisome rod increased the overall energy transfer time by 30 +/- 5 picoseconds. In the isolated phycobiliproteins the onset of emission was as prompt as that of a solution of rhodamine B laser dye and was independent of excitation wavelength. This imposes an upper limit of 8 picoseconds (instrument-limited) on the transfer time from "sensitizing" to "fluorescing" chromophores in these biliproteins. These results indicate that disk-to-disk transfer is the slowest energy transfer process in phycobilisomes and, in combination with previous structural analyses, show that with respect to energy transfer the lattice of approximately 625 light-harvesting chromophores in the Synechocystis 6701 wild-type phycobilisome functions as a linear five-point array.
我们使用一台宽调谐皮秒激光源和一台超快条纹相机，测量了完整藻蓝体和单个藻胆蛋白在激发波长下的时间和光谱分辨发射。我们检测了单细胞蓝藻集胞藻 6701 的野生型和突变型藻蓝体，以及两种藻胆蛋白，藻红蛋白（240 千道尔顿，34 个藻胆素）和别藻蓝蛋白（100 千道尔顿，6 个藻胆素）。对具有已知结构差异的完整藻蓝体的测量表明，藻蓝体杆中添加平均 1.6 个藻红蛋白盘会使整体能量转移时间增加 30 ± 5 皮秒。在分离的藻胆蛋白中，发射的起始时间与罗丹明 B 激光染料溶液一样快，且与激发波长无关。这在这些藻胆蛋白中，将“敏化”发色团到“荧光”发色团的转移时间限制在 8 皮秒以内（仪器限制）。这些结果表明，盘对盘的转移是藻蓝体中最慢的能量转移过程，并且结合先前的结构分析表明，就能量转移而言，集胞藻 6701 野生型藻蓝体中约 625 个光捕获发色团的晶格作为线性五点阵列发挥作用。
