STABILIZATION AND PARTIAL-PURIFICATION OF TRITON X-100 SOLUBILIZED TRIHYDROXYCOPROSTANOYL-COA SYNTHETASE FROM RAT-LIVER

The stability of rat hepatic trihydroxycoprostanoyl-CoA syntethase was studied in its native membrane environment and after solubilisation b y Triton X-100, and compared to that of choloyl-CoA synthetase. The la bility of both delipidated enzymes could be suppressed by high concent rations of polyols such as sucrose and glucose. Addition of phospholip ids to the assay mixtures was necessary to restore the activity of the stabilized enzymes. For further chromatographic separations, the addi tion of the hydrotrope Triton H-66 to the glucose-stabilized Triton X- 100 solubilised synthetases improved their recovery on different matri ces. Gel filtration revealed a native molecular mass of the Triton X-1 00/Triton H-66/protein micelles of 212 and 207 kDa for choloyl-CoA syn thetase and trihydroxycoprostanoyl-CoA synthetase respectively.