Free and membrane-bound ribosomes. II. Two-dimensional gel electrophoresis of proteins from free and membrane-bound rabbit reticulocyte ribosomes.

Free and membrane-bound polysomes were isolated from rabbit reticulocytes. The membrane-bound polysomes were liberated form the membrane with deoxycholate. Monosomes were prepared from the two types of polysomes by incubation with puromycin. The ribosomal proteins were extracted and analyzed by two-dimensional gel electrophoresis. Two proteins of the large subunit, L11 and L17 present in the free monosomes were not found in the membrane-bound monosomes. On the other hand, four additional spots were found in the protein pattern of the membrane-bound monosomes.