Effects of CaCl2-washing on EPR Signals of Cytochromeb559in Photosystem II Preparation from Spinach Chloroplasts

摘要

Washing of PS II preparation by 1mCaCl2inactivates oxygen evolution without loss of bound manganese [Ono and Inoue (1983)FEBS Lett. 164: 255]. Most of the high-potential Cytb550, which amounts to about a half of the total Cytb559in untreated preparation, was converted to its low-potential form by CaCl2-washing. The effect was similar to that of Tris-washing. The peak position of thegsband of the EPR spectrum of the CaCl2-washed preparation (g=2.95) was the same as that of the low potential form of untreated preparation but was slightly different from that of the Tris-washed or heat-treated preparation (g=2.98).