Preparative two-dimensional polyacrylamide gel electrophoresis of rat liver ribosomal proteins and determination of their amino acid compositions

Abstract

1. By enlarging the dimensions of the gels used in the usual analytical two-dimensional polyacrylamide gel electrophoresis it is possible to separate much larger amounts of ribosomal protein in comparison to analytical separations. 15 mg of protein mixture of small or large subunits of rat liver ribosomes can be separated by this procedure. 2. The positions of the proteins in the two-dimensional patterns are identified with a special staining procedure. The proteins are eluted from the gels with SDS phosphate buffers. 3. The purity of the extracted proteins was tested by one-dimensional SDS-polyacrylamide gel electrophoresis and two-dimensional electrophoresis, respectively. 24 proteins of the small and 24 proteins of the large ribosomal subunit were isolated in pure form. 4. The amino acid compositions of 24 proteins of the small and of 19 proteins of the large subunit were determined.