Novel fractionation of proteins using novobiocin as a precipitating agent: application to ribosomal proteins from the archaebacterium Sulfolobus acidocaldarius and Escherichia coli.

A fractionation method involving precipitation of proteins with novobiocin has been developed to separate ribosomal proteins of the archaebacterium Sulfolobus acidocaldarius. Four groups of proteins were obtained corresponding to those precipitated with 0.2, 0.5 and 1.0 mg/ml novobiocin and the proteins soluble at 1.0 mg/ml novobiocin. The same procedure was also successful for the fractionation of ribosomal proteins from Escherichia coli. Two dimensional gel electrophoresis showed that proteins present in each group were distinct with only a minor contamination of proteins from other groups. Our results indicate that proteins with similar charge and molecular weight can be separated by this method. This procedure may have applications for the fractionation of other complex protein mixtures.