中文摘要：

以基因重组别藻蓝蛋白三聚体为材料,利用原子力显微镜观察到了单分子重组别藻蓝蛋白三聚体的纳米级分辨率的三维图像（短轴约为1.5 nm,长轴约为15 nm的盘状颗粒）,与通过透射电子显微镜和X射线晶体衍射得到的天然APC三聚体的圆盘状结构的尺寸十分接近.通过测量荧光发射光谱、吸光光谱和圆二色光谱,对自组装重组别藻蓝蛋白三聚体的正确组装进行了证实.获得了较宽pH范围内的紫外光区（190~250 nm）和可见光区（450~750 nm）圆二色谱数据,通过紫外光区圆二色谱解析,确定了a螺旋是重组别藻蓝蛋白三聚体二级结构的主要组成部分.可见光区圆二色谱解析为别藻蓝蛋白三聚体中存在藻蓝胆素激子耦合对,以及耦合体内以激子分裂进行能量传递提供了证据.本文结果进一步证实,与天然别藻蓝蛋白三聚体相比较,基因重组别藻蓝蛋白三聚体有正确的能量传递功能.

英文摘要：

Nature has been developing and optimizing photosynthesis billions years, including green plants, algae, photosynthetic bacteria and cyanobacteria. Phycobiliproteins system, as the pbycobilisomes, in cyanobacteria and red algae is the one of two major light-harvesting systems, after evolution in billions years. Allophycocyanin （APC） trimer is a primary composition of phycobilisomes core for efficient lower-energy photons funneling pathway. In 2009, Liu et al. have firstly assembled the highly soluble self-assembled recombinant APC tfimer with N-terminus polyhisfidine, which the entire biosynthesis pathway of APC trimer was reconstituted in Escherichia coli strain with the full-length genes of apoprotein c~ subunit and 13 subunit from Synechocystis sp. PCC 6803. The recombinant APC trimer was used to be the subject in this research. An optimum protocol with immobilized metal-ion affinity chromatography with chelating transition metal ion （Ni2＋） was used to purify the recombinant protein. Then, the second purification was performed to obtain APC trimer with a higher purity （A650/A6z0=l.346）, using density gradient centrifugation. Single molecules of recombinant APC trimers were investigated with atomic force microscopy. Three-dimensional images with resolution at nanoscale indicated that the recombinant allophycocyanin trimers were approximately 1.5 nm in short axis, and 15 nm in long axis, which were in accordance with the sizes of natural allophycocyanin trimer measured by transmission electron microscopy or X-ray crystallography. Moreover, the correct conformation of recombinant allophycocyanin trimer was confirmed by fluorescence spectra （studied energy transfer ability）, absorption spectra （studied the light-harvesting ability）, and circular dichroism （CD） spectra （studied changes of secondary structure and aggregation state）. The CD spectra of recombinant allophycocyanin induced by a wide range of pH were analyzed both at wavelengths in ultraviolet range （190-250 nm） and visib