Electrophoresis of ribosomal proteins according to Kaltschmidt and Wittmann, 1970a, b (pH 8.6/pH 4.5 urea system) yielded 29 proteins for the small subunits and 35 and 37 proteins for the large subunits of Krebs II ascites and HeLa ribosomes, respectively. Analysis of the proteins according to a modified technique by Mets and Bogorad (1974) (pH 4.5/pH 8.6 SDS system) revealed 28 and 29 proteins in the small subunits and 37 and 38 proteins in the large subunits of Krebs II ascites and HeLa ribosomes. The molecular weights of the individual proteins were determined by: 1. "three-dimensional" gel electrophoresis; 2. two-dimensional gel electrophoresis at pH 4.K/pH 8.6 in SDS. The molecular weights for 40S proteins ranged from 10,000 to 39,000 dalton (number average molecular weight: 21,000). The molecular weights for the 60S proteins ranged from 14,000 to 44,000 dalton (number average molecular weight: 23,000) using the "three-dimensional" technique. A molecular weight range from 10,000 to 38,000 dalton (number average molecular weight: 21,000) was obtained for the 40S subunits, whereas the molecular weights for the 60S ribosomal proteins (average molecular weight: 26,000) ranged from 12,000 to 69,000 dalton using the pH 4.5/pH 8.6 SDS system. The molecular weights Krebs II ascites and HeLa ribosomal proteins are compared with those obtained by other authors for different mammalian species.
Molecular General Genetics, 1978, Vol 160, Issue 3, p. 297-309