Partial purification and characterization of oxidosqualene-lanosterol cyclase from baker's yeast

Article abstract of DOI:10.1016/S0040-4020(01)86485-1

Partial (120-fold) purification of oxidosqualene-lanosterol cyclase from yeast is described. The enzyme derived from the microsomal fraction converts 1 mM S-squalene oxide to lanosterol in 5 h and has a pH optimum of 6.2, lower than that (pH 7.2) of the hog-liver cyclase catalyzing the same reaction. Although the yeast cyclase is stimulated by high concentrations of potassium phosphate buffer, high concentrations of potassium or sodium chloride inhibit activity. The concentration range of Triton X-100 for optimal activity is 0.7-1.2%.