A comparative study of the photosystem II membrane proteins with natural lipids in monolayers

Monolayers of the photosystem II core particles (PSIICP) and Light-harvesti ng complexes from spinach and their mixtures with the following lipids: pho sphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidy linositol, phosphatidylglycerol and digalactosyldiglyceride (DGDG) were pre pared and investigated. Strong interaction between PSIICP and DGDG was foun d as compared to other lipids. The standard protein bands for PSIICP were f ound by electrophoresis (SDS PAGE) in all samples taken from the interface of the mixed lipid-protein monolayers, but not in those from the aqueous su bphase. At surface pressure 40 mN/m, these protein bands remained the same only for mixed monolayers with DGDG. The damage of PSIICP by illumination i n the lipid monolayers and strong binding of the remaining polypeptides wit h DGDG were shown. (C) 1999 Elsevier Science B.V. All rights reserved.