PROPERTIES OF PHOTOSYSTEM-II PIGMENT LIPID-PROTEIN COMPLEXES FROM BEAN CHLOROPLAST THYLAKOID MEMBRANES

Photosystem II pigment-lipid-protein complex (PS II PI,PC)(3) with pro tein component molecular weight 470 kD (PLPC-470) was isolated from be an chloroplast thylakoid membranes under conditions which retain polar lipids and sub-fractionated into complexes with protein molecular wei ghts of 360 and 110 kD (PLPC-360 and PLPC-110). The fatty acid and pol ypeptide compositions (the latter by electrophoresis in polyacrylamide gel) of the PS II PLPCs were determined: PLPC-470 contains 53, 47, 43 , 27, 23, and 14 kD polypeptides; PLPC-360 contains 53, 47, 43, 27, an d 14 kD polypeptides; PLPC-110 contains 27 and 14 kD polypeptides. Fou r phosphatidylglycerol molecules and three phosphatidylcholine molecul es are associated with one chlorophyll a molecule in PLPC-360 and PLPC -110; chlorophyll b was found only in PLPC-110. PLPC-470, PLPC-360, an d PLPC-110 exhibit two low-temperature fluorescence emission maxima, a t 685 and 695 nm. PLPC-470 exhibits two absorption maxima (671 and 691 nm) in the red region of the spectrum at ambient temperature.