用NaCl洗涤、低pH或去垢剂OG等方法处理PSⅡ颗粒,其放氧活性明显降低,外加Ca~(2+)可使受抑制的放氧活性恢复.用Ca~(2+)重组动力学分析,盐洗或低pH处理后的PSⅡ 颗粒均存在亲和性不同的2个Ca~(2+)结合位点,但有所差异;具放氧活性的PSⅡ核心复合物也同样存在高、低亲和性Ca~(2+)结合位点.Ca~(2+)可使PS Ⅱ核心复合物的荧光发射峰强度改变.这些结果表明:Ca~(2+)在PS Ⅱ中有2种功能,低亲和位点Ca~(2+)与光能传递有关,高亲和位点Ca~(2+)与水裂解反应相关. Treatment of PSⅡ particles with NaCl, low pH or detergent OG showed that the oxygen evolution activity of the PSⅡ particles was significantly reduced, and the inhibited oxygen evolution activity was restored by the addition of Ca 2+. There were two Ca ~ (2+) binding sites with different affinities in PS Ⅱ particles after salt washing or low pH treatment, but there were some differences between them. PS Ⅱ core with oxygen activity also existed high , Low affinity Ca 2+ binding sites.Ca 2+ can change the fluorescence emission intensity of PS Ⅱ core complexes.These results show that Ca 2+ in PS Ⅱ Two kinds of functions, low affinity sites Ca ~ (2+) and light energy transfer, high affinity sites Ca ~ (2+) and water cracking reaction.