CHLOROPHYLL LEVELS IN THE PIGMENT-BINDING PROTEINS OF PHOTOSYSTEM-II - A STUDY BASED ON THE CHLOROPHYLL TO CYTOCHROME RATIO IN DIFFERENT PHOTOSYSTEM-II PREPARATIONS

The chlorophyll levels in pigment proteins of photosystem II were investigated by using photosystem II preparations with different levels of complexity. Based on the assumption that there is 1 cytochrome b559 per reaction centre it has been found that oxygen-evolving complexes containing CP26 and CP29 bind 42 chlorophyll molecules. When CP26 and CP29 are stripped away, the resulting PSII cores bind 30 chlorophyll molecules while CP43-less cores bind approximately 18 chlorophylls. It is therefore concluded that CP47 and CP43 bind 9-12 molecules of chlorophyll a and the D1/D2 complex binds 6 chlorophylls. Taken together CP26 and CP29 bind about 12 chlorophyll molecules.