Preparation protocols for high-activity Photosystem II membrane particles of green algae and higher plants, pH dependence of oxygen evolution and comparison of the S-2-state multiline signal by X-band EPR spectroscopy

Photosystem II (PS II) membrana particles are particularly well suited for various types of spectroscopic investigations on the PS II manganese comple x. Here we present: ( I) a preparation protocol for PS II membrane particle s of higher plants, which yields exceptionally high oxygen-evolution activi ty due to the use of glycinebetaine as a PS II-stabilizing agent; (2) prepa ration protocols for highly active PS II membrane particles for the green a lgae Scenedesmus obliquus and Chlamydomonas reinhardtii; (3) a determinatio n of pH dependence of oxygen evolution for spinach and Scenedesmus; (4) a c omparison of the EPR multiline signal observed in the S-2-state of green al gae and higher plants of PS II membrane particles. A clearly broader type o f multiline EPR signal is observed in green algae. (C)2000 Elsevier Science S.A. All rights reserved.