Anion-exchange HPLC fractionation of the cytosolic fraction. (A) The cytosolic fraction was further fractionated using an anion-exchange column (Accell QMA) with a step-gradient of increasing concentrations of ammonium bicarbonate (straight lines). The concentrations are indicated on each step while absorbance was measured at 280 nm indicating the protein yield of each fraction. (B) The Coomassie blue-stained SDS-PAGE gel shows the fractionation of the cytosolic sample (total) with the lanes corresponding to the cytosolic fractions below the peaks of the HPLC chromatogram. Note the resulting enrichment of certain protein bands. Relative molecular weights of protein standards are indicated in kDa.