Abstract
Ion effects on $11{\alpha}-hydroxylation$ of progesterone and $5{\alpha}-reduction\;of\;11{\alpha}-hydroxyprogesterone$ by Rhizopus nigricans were investigated. Metal ions such as $Cu^{2+},\;Cd^{2+},\;Co^{2+},\;Mn^{2+},\;Zn^{2+},\;Fe^{2+},\;Mg^{2+},\;Fe^{3+}\;and\;Na^+$ reduced the $11{\alpha}-hydroxylation$ activity, while $K^+$ stimulated the same reaction. Enzyme activity for the $5{\alpha}-reduction$ of $11{\alpha}-hydroxyprogesterone$ was increased in the presence of $Fe^{2+},\;Mn^{2+},\;Mg^{2+},\;Co^{2+},\;Zn^{2+},\;Fe^{3+},\;K^+\;and\;Na^+$, whereas it was decreased in the presence of $Cd^{2+}\;and\;Cu^{2+}$. Potassium ion of $10^{-3}\;M\;$ of concentration was found to be effective for the promotion of $11{\alpha}-hydroxylation$. On the other hand, cadmium ion of $10^{-4}\;M$ was proved to suppress the $5{\alpha}-reduction$ reaction. Progesterone is reported to be transformed into $11{\alpha}-hydroxyprogesterone$ which, in turn, is converted further into $11{\alpha}-hydroxy-allopregnane-3$, 20-dione by R. nigricans. From this point of view, the highest yield of $11{\alpha}-hydroxyprogesterone$ could be obtained when potassium ion of $10^{-3}\;M$ was given initially followed by addition of cadmium ion of $10^{-4}\;M$ to limit conversion of 11{\alpha}-hydroxyprogesterone into $11{\alpha}-hydroxy-allopregnane-\;3$, 20-dione.
Rhizopus nigricans에 의한 progesterone의 $11{\alpha}-hydroxylation$과 ${5\alpha}-reduction$반응에 미치는 이온의 효과를 조사하였다. $Cu^{2+},\;Cd^{2+},\;Co^{2+},\;Mn^{2+},\;Zn^{2+},\;Fe^{2+},\;Mg^{2+},\;Fe^{3+}$ 및 $Na^+$은 $11{\alpha}-hydroxylation$ 반응의 활성을 저하시켰으나 $K^+$은 이 반응을 촉진시켰다. $11{\alpha}-hydroxyprogesterone$을 $5{\alpha}-reduction$시키는 효소는 $Fe^{2+},\;Mn^{2+},\;Mg^{2+},\;Co^{2+},\;Zn^{2+},\;Fe^{2+},\;K^+,\;Na^+$에 의하여 그 활성이 증가되었고 $Cd^{2+}$과 $Cu^{2+}$은 이 반응을 억제하였다. $11{\alpha}-hydroxylation$ 반응을 촉진하는데는 $10^{-3}\;M$의 $K^+$이 효과적이었으며 $5{\alpha}-reduction$반응을 엑제하기 위하여는 $10^{-4}\;M$의 $Cd^{2+}$이 적합하였다. R. nigricans는 세포내의 다효소체계에 의하여 progesterone이 $11\{alpha}-hydroxyprogesterone$으로 전환된 후 $11{\alpha}-hydroxy-allopregnane-3, 20-dione으로 $5{\alpha}-reduction$되므로 $10^{-3}\;M$의 $K^+$을 먼저 첨가하여 2시간 동안 progesterone 전환 반응을 실시한 후에 $10^{-4}\;M$의 $Cd^{2+}$을 첨가하였을 때 가장 높은 $11\{alpha}-hydroxyprogesterone$의 수득률을 얻을 수 있었다.