MIXED LIPID-PROTEIN FILMS OF BACTERIAL PH OTOSYNTHETIC REACTION CENTERS .1. INVESTIGATION OF MIXED MONOLAYERS AT THE AIR WATER INTERFACES/

Mixed lipid-protein monolayers composed of reaction center (RC) protei ns and lipids were investigated. RCs were isolated from Chloroflexus a urantiacus and Rhodobacter sphaeroides (wild type) photosynthetic bact eria and mixed with natural and synthetic lipids. The optimal subphase conditions for forming monolayers composed of phosphatidylcholine - R C (1:26. M/M) and phosphatidylethanolamine - RC (1:26, MFI) were deter mined. The optimal parameters of the water subphase were found to be 1 0 mM phosphate buffer (pH 7,0) and 20 degrees C. The monolayers were t ested for their stability under constant surface pressure.