Preparative isolation of distinct molecular forms of rabbit liver ferritin using high-performance liquid...

Rabbit liver ferritin was separated to fractions of distinct molecular form using a chromatofocusing column coupled to high-performance liquid chromatography equipment. This purification method was fast, less than 1 h, and enabled preparation of fractions, highly enriched in particular subtypes of ferritin. Analytical isoelectrofocusing of these fractions demonstrated a gradual shift in the range of isoelectric points of these subtypes of ferritin. Gradient-pore polyacrylamide slab-gel electrophoresis showed a distinct shift in the subunit ratio of the ferritins, ranging from 87% low molecular weight (L) subunit in the first fraction eluting at a pH 5.4, to 28% L-subunit in the fraction eluting in the trailing edge of the protein peak at pH 4.0. The pI range of the fractions covered the complete range, from pH 4.9 to pH 5.4, of isoelectric points of the whole rabbit liver ferritin preparation.