Physicochemical properties of charge-transfer complexes of plastoquinone and alpha-tocopherol quinone, and their possible role in vivo.
It has been found that the solubility of PQH2 and alpha-TQH2 in hexane increased with the increase in PQ and alpha-TQ concentrations, respectively, that is connected with the formation of quinhydrone-type charge-transfer complexes. Measurements of the solubility of both prenylquinones and their reduced forms in hexane and acetone, at -30 degrees C and room temperature, showed a much higher affinity of the quinol forms for acetone than for hexane. In the case of quinones, the difference in affinity was not significant. The possibility of charge-transfer complex formation by PQ and alpha-TQ in thylakoid membranes and the influence of such complexes on the diffusion of PQH2 and alpha-TQH2 molecules have been considered.
Kruk
J
J
Department of Physiology and Biochemistry of Plants, Institute of Molecular Biology, Jagiellonian University, Al. Mickiewicza 3, 31-120 Cracow, Poland.