Purification of squalene‐2,3‐epoxide cyclases from cell suspension cultures of Rabdosia japonica Hara

Microsomes prepared from cell suspension cultures of Rabdosia japonica Hara showed activities for cyclizing squalene‐2,3‐epoxide into cycloartenol, β‐amyrin and α‐amyrin in the presence of Triton X‐100. These activities were efficiently solubilized by treatment with Triton X‐100 and separated by chromatography on hydroxy apatite, DEAE‐cellulose, isoelectric focusing and gel filtration. The purified cycloartenol cyclase showed a single band on SDS‐polyacrylamide gel electrophoresis with Mr = 54000, while β‐amyrin cyclase gave a single band with Mr = 28000.