Analysis of Blastocladiella emersonii ribosomal proteins in four two-dimensional gel electrophoresis systems.

Ribosomal proteins of the aquatic fungus Blastocladiella emersonii were isolated and characterized on four different two-dimensional polyacrylamide gel electrophoresis systems. 40S and 60S ribosomal subunit proteins from zoospores were identified. The position of every protein was determined in each electrophoretic system using the "four-corners" method (Madjar et al., Molecular and General Genetics, 171: 121-134, 1979). Thirty-two and 39 proteins were identified in the 40S and 60S ribosomal subunits, respectively. The molecular weights of individual proteins in the 40S subunit ranged from 10 000 to 37 000, with a number-average molecular weight of 20 000. The molecular weight range for the 60S subunit was 13 000-51 000 with a number-average molecular weight of 21 000. Proteins from ribosomes of different cell types were compared and found to be qualitatively indistinguishable. The only consistent difference in the patterns of proteins was in the S6 protein of the 40S subunit, which is the major phosphoprotein of Blastocladiella ribosomes.