Cholesterol esterase was purified about 85 times from the broth filtrate of Streptomyces lavendulae by procedures involving precipitation with ammonium sulfate, reprecipitation with acetone, affinity chromatography on palmitoyl cellulose, and ion exchange chromatography on DEAE-cellulose. The purified enzyme showed a single band on polyacrylamide disc gel electrophoresis and SDS-polyacrylamide gel electrophoresis, and the specific activity of the enzyme was 36.3 U/mg. The molecular weight of the enzyme was 12000 as determined by SDS-polyacrylamide gel electrophoresis. The enzyme showed different properties from other cholesterol esterases as regards its affinity for cholesterol.
