Contribution of LHC II complex to the electric properties of thylakoid membranes: an electric light scattering study of Chl b-less barley mutant

Electric light scattering measurements demonstrate a strong decline in the permanent electric dipole moment and electric polarizability of both thylak oid membranes and photosystem IT-enriched particles of the Chlorina f2 muta nt which has severely reduced levels of light-harvesting chlorophyll a/b-bi nding proteins compared to the wild type barley chloroplasts. The shift in the electric polarizability relaxation to higher frequencies in thylakoids and photosystem II particles from Chlorina f2 reflects higher mobility of t he interfacial charges of the mutant than that of the wild type membranes. The experimental data strongly suggest that the major light-harvesting comp lex of photosystem II directly contribute to the electric properties of thy lakoid membranes. (C) 2000 Elsevier Science S.A. All rights reserved.