[Isolation, fractionation and comparative analysis of the cell membranes of the cyanobacterium, Anabaena variabilis]

A homogenate prepared from the protoplasts of Anabaena variabilis was fractionated by differential centrifugation and zonal electrophoresis. Four subcellular fractions were isolated and characterized with respect to their composition and morphology, two of them being of the membranous nature. Membrane visicles from the light, chlorophyll-containing fraction were identified as small fragments of thylakoids while the pigment-deficient, heavy membrane fraction seemed to be represented by fragments of the cytoplasmic membrane.