A model for chloroplast thylakoid membranes involving orderly arrangements of negatively charged lipidic particles containing sulphoquinivosyl-diacylglycerol

Addition of sulphoquinivosyl-diacylglycerol (SL) to mixtures of monogalactosyl-diacylglycerol (MG) and digalactosyl-diacylglycerol (DG) induces the appearance of paracrystalline arrays of 80-100 angstrom lipidic particles. The hypothesis is presented that SL occupies the position in the leaflet opposite the micelle of MG or the position in the leaflet on the convex side of the bulge or cusp in the corresponding model for lipidic particles, and that these orderly arranged lipidic particles containing negatively charged SL may form part of the basis for the orderly arrangement of other molecules functioning in photosynthesis in the thylakoid membrane.