Determination of the Number of Proteins in Liver Ribosomes and Ribosomal Subunits by Two-Dimensional Polyacrylamide Gel Electrophoresis

Abstract

Abstract The number of proteins in rat liver ribosomes was determined by two-dimensional polyacrylamide gel electrophoresis. There were 30 proteins in the 40 S subunit, 39 in the 60 S subunit. The proteins of the two subunits, with one possible exception, are unique. Preparations of 80 S ribosomes contained three proteins not present in either subunit; thus, we estimate that eukaryotic ribosomes contain between 68 and 72 different proteins.