| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject enzyme, a pregnenolone oxidase having the action to form progesterone and hydrogen peroxide through acting on pregnenolone, and useful for pregnenolone assay, progesterone production, etc. SOLUTION: This new pregnenolone ocidase has the action to form progesterone and hydrogen peroxide through acting on pregnenolone in the presence of oxygen, having such substrate specificity that when its activity is assayed at 37 deg.C and pH 7.0 using 0.1 mM substrate, the ratio of cholesterol oxidative activity to pregnenolone oxidative activity is <=0.3. This new enzyme, being high in pregnenolone oxidative activity, is useful for pregnenolone assay, progesterone production, etc. This enzyme is obtained by the following procedure: a chromosomal DNA is extracted from Streptomyces sp. SA-COO and digested with a restriction enzyme to bind the resultant fragment to a vector, the resultant vector is then introduced into host cells and cloned, a gene obtained from the resultant positive clone is then integrated into an expression vector and expressed in host cells. |
