[Structure of higher plant chloroplast membranes as studied by paramagnetic probes].

A study of interaction between ten different spin labels and bean chloroplast membranes was carried out. It was found that spin labels were localized in three characteristic regions of the membrane. These regions differ in density and mode of the lipids package. The processes of light--induced reduction (with loss of paramagnetism) and reoxidation of spin labels are due to the interaction with the components of electron-transport chain between photosystems I and II. The kinetics of redox-changes of spin labels depends on the site of the paramagnetic fragment location in membrane.