Lendzian, F.; Lubitz, Wolfgang; Scheer, Hugo; Hoff, Arnold J.; Plato, M.; Tränkle, E.; Möbius, K.
ESR, ENDOR and TRIPLE resonance studies of the primary donor radical cation P960+ in the photosynthetic bacterium Rhodopseudomonas viridis.
In: Chemical Physics Letters, Vol. 148, No. 5: pp. 377-385
The light-induced radical cation of the primary electron donor P960+• in photosynthetic reaction centers from Rhodopseudomonas viridis has been investigated by ESR, ENDOR and TRIPLE techniques. Both the comparison with the cation radical of monomeric bacteriochlorophyll b (BChl b) and with molecular-orbital calculations performed on P960+• using the results of an X-ray structure analysis, consistently show an asymmetric distribution of the unpaired electron over the two BChl b molecules which constitute P960+•. The possible relevance of this result for the primary electron transfer step in the reaction center is briefly discussed.