Temperature-induced changes in the surface electric properties of thylakoids and photosystem II membrane fragments

The effect of heat treatment on the surface electric properties of thylakoid membranes and photosystem II-enriched membrane fragments is studied by electric light scattering. The electric dipole moments and the dimensions of both thylakoid and photosystem II-enriched membranes are shown to depend strongly on the temperature. The thermal-induced decrease in the electric dipole moments of thylakoids and photosystem II fragments correlates with heat-induced inactivation of the photochemical activity of photosystem II and structural reorganization of the macroassemblies in thylakoid membranes.