A simplified purification and some properties of ribulose 1,5-diphosphate carboxylase from barley

A rapid procedure was developed for purifying ribulose 1,5-diphosphate carboxylase from barley leaves. After (NH₄)₂SO₄ fractionation, the unique sedimentation properties of the enzyme were exploited to effect a single step purification to 90% homogeneity. High speed centrifugation pelleted the enzyme with complete recovery of activity. Residual impurities were then removed by diethylaminoethyl cellulose chromatography and density gradient centrifugation. The purified protein exhibited size heterogeneity due to polymerization. The polymerization products were enzymatically active aggregates of ribulose 1,5-diphosphate carboxylase and were precipitated by an antibody specific for the enzyme.