Artificial Alterations of Fluidity of Pea Thylakoid Membranes and Its Effect on Energy Distribution between Both Photosystems

Abstract

Two different membrane perturbing agents -cholesterol and benzyl alcohol were applied to modify the fluidity of pea thylakoid membranes. Well pronounced decrease of membrane fluidity was observed upon increasing of cholesterol added. Rigification of thylakoid membranes was accompanied by reduction of cation-induced increase of light-scattering intensity and results in lower extent of increase of spillover upon cation induced stack-unstack transi­tion. Thylakoid membranes, treated with local anesthetic benzyl alcohol, showed an increase of membrane fluidity, but approximately the same behavior as untreated thylakoids in respect to the light scattering intensity dependence on cation concentration. Upon stack-unstack transition the observed changes of energy distribution for benzyl alcohol treated thylakoids are similar to those for controls. The data are discussed in terms of influence of membrane fluidity on lateral reorganization of pigment-protein complexes.