蓝藻藻胆体与菠菜光系统Ⅱ颗粒之间的能量传递

ENERGY TRANSFER FROM CYANOBACTERIAL PHYCOBILISOMES TO SPINACH PHOTOSYSTEM Ⅱ PARTICLES

制备了嗜热蓝藻优雅粘囊藻（ＭｙｘｏｓａｒｃｉｎａｃｏｎｃｉｎｎａＰｒｉｎｔｚ）的藻胆体和菠菜（ＳｐｉｎａｃｉａｏｌｅｒａｃｅａＭｉｌ．）的光系统Ⅱ颗粒，测定了它们的吸收光谱和低温荧光光谱。研究了藻胆体与菠菜光系统Ⅱ颗粒的能量传递。发现藻胆体不仅能将吸收的光能有效地传递给菠菜的光系统，而且能量传递的效率随着反应体系离子强度的升高而升高（ＫＨ２ＰＯ４，０１～０．５ｍｏｌ／Ｌ）。用５５８ｎｍ的光激发，可以测到菠菜光系统Ⅱ颗粒的放氧活性显著升高，进一步表明藻胆体可以将激发能传递给菠菜的光系统Ⅱ。

The phycobilisomes (PBS) from the thermophilic cyanobacterium Myxosarcina concinna Printz and the PSⅡ particles from Spinacia oleracea Mill. were isolated. Their spectral characteristics were defined and the light energy transfer from PBS to PSⅡ was studied. As the ion intensity (KH2PO4) of the buffer system increased from 0.1 mol/L to 0.5 mol/L, the efficiency of the energy transfer also increased. The PSⅡ particles had a higher water splitting activity. When excited with light at 558 nm, there was a significant rise of the activity of O2 evolution which further indicated that the excitation energy harvested by PBS could transfer to the PSⅡ particle from spinach.