Rapid purification of D-ribulose 1,5-bisphosphate carboxylase by vertical sedimentation in a reoriented gradient

Using a vertical rotor, ribulose bisphosphate carboxylase has been purified by a 2-h sedimentation of crude cell-free preparations of fresh spinach, crude commercial spinach enzyme or salt-fractionated fresh barley extracts into linear 0.2-0.8 M sucrose gradients. In some cases, the barley enzyme had been previously precipitated with (NH₄)₂SO₄. The products which are pure by the criterion of electrophoresis in gels polymerized from several concentrations of acrylamide have high specific enzyme activities. The procedure is more effective than analogous centrifugation in a fixed-angle rotor and is far superior to that in a swinging bucket rotor.