Quenching of chlorophyll fluorescence by triplets in solubilized light-harvesting complex II (LHCII).

The quenching of chlorophyll fluorescence by triplets in solubilized trimeric light harvesting complexes was analyzed by comparative pump-probe experiments that monitor with weak 2-ns probe pulses the fluorescence yield and changes of optical density, DeltaOD, induced by 2-ns pump pulses. By using a special array for the measurement of the probe fluorescence (Schödel R., F.

Functional and structural analysis of photosystem II core complexes from spinach with high oxygen evolution capacity.

Oxygen-evolving photosystem II core complexes were prepared from spinach by solubilizing photosystem II membrane fragments with dodecyl-beta-D-maltoside. The core complexes consist of the intrinsic 47-kDa, 43-kDa, D1 and D2 polypeptides, the two subunits of cytochrome b559 and the extrinsic 33-kDa protein. In the presence of 50 mM CaCl2 they exhibit a high oxygen evolution rate of 1.