Biosystemes membranaires Bat. 24, C.N.R.S., 1 Av. de la Terrasse, 91198, Gif-sur-Yvette Cedex, France.
Photosynth Res. 1993 Sep;37(3):205-15. doi: 10.1007/BF00032824.
Flash-induced absorption changes at 515 nm observed as a function of flash number are examined in relation to the flash-induced fluorescence yields in inside-out thylakoids. After partial dissipation of the delocalized transmembrane electric field by adding gramicidin, the analysis of period 4 oscillations and of the kinetics in the 10 ms-1 s range suggest that the variation of the absorption changes at 515 nm as a function of flash number is the result of at least two processes:1) an electric field increase related to the S2 state and 2) the fact that the field generated by the water protons inside the membrane decreases when these protons are released outside the membrane. The former field correlates with the flash-induced fluorescence yield increase induced by the donor side of Photosystem II. Both measurements show similar oscillations as a function of flash number, with maxima on the 1st, 5th and 9th flash. These oscillations, after a shift of two flashes, appear to be different from those of the O2 yield observed under similar conditions. It is proposed that, in a population of centers the electric field during the S2 state reflects the presence of a stabilized positive equivalent in the protein close to the Mn complex.
以闪光次数为函数观察到的 515nm 光诱导吸收变化与类囊体膜内的光诱导荧光产率有关。在添加短杆菌肽后部分耗散非定域跨膜电场后，对周期 4 振荡和 10ms-1s 范围内的动力学的分析表明，515nm 处的吸收变化随闪光次数的变化是至少两个过程的结果：1）与 S2 态相关的电场增加，以及 2）当膜内的水分子质子释放到膜外时，膜内生成的电场减小。前一个电场与由光合作用系统 II 的供体侧诱导的光诱导荧光产率增加相关。这两种测量都显示出与闪光次数相关的类似的振荡，在第一、第五和第九个闪光时有最大值。在经过两次闪光的位移后，这些振荡似乎与在类似条件下观察到的 O2 产率的振荡不同。有人提出，在一个中心群体中，S2 态期间的电场反映了在 Mn 配合物附近的蛋白质中存在稳定的正当量。
