In replacement culture with a formycin-producing strain. Steptomyces sp. MA406-A-1, exogenously added formycin B was quantitatively converted to formycin and the conversion was inhibited by adding the chromophore moiety of formycin. 2. The in vitro experiments revealed that the novel enzyme(s) catalyzing the formation and formycin from asparate and formycin B, but not from formycin B monophosphate, was present in this organism. The action of the partially purified enzyme(s) was also inhibited by the chromophore moiety of formycin, whereas the moiety showed no inhibitory effect on the actions of adenylosuccinate synthetase and adenylosuccinate lyase. 3. Adenine auxotrophs lacking either adenylosuccinate synthetase or adrenylosuccinate lyase were derived from strain MA406-A-1 and these auxotrophs were found to readily convert formycin B to formycin in replacement culture. From these results, it was estimated that, under the conditions of replacement culture, formycin B would be converted to formycin in vivo by the action of novel enzyme(s) rather than by the action of enzyme system including adenylosuccinate synthetase and adenylosuccinate lyase.
摘要
在使用产间型霉素菌株链霉菌属MA406 - A - 1进行补充培养时，外源添加的间型霉素B被定量转化为间型霉素，并且添加间型霉素的发色团部分可抑制这种转化。2. 体外实验表明，该生物体中存在一种新型酶，可催化由天冬氨酸和间型霉素B形成间型霉素，但不能由间型霉素B单磷酸形成间型霉素。部分纯化的酶的作用也受到间型霉素发色团部分的抑制，而该部分对腺苷酸琥珀酸合成酶和腺苷酸琥珀酸裂解酶的作用没有抑制作用。3. 从菌株MA406 - A - 1获得了缺乏腺苷酸琥珀酸合成酶或腺苷酸琥珀酸裂解酶的腺嘌呤营养缺陷型菌株，发现这些营养缺陷型菌株在补充培养中能轻易地将间型霉素B转化为间型霉素。根据这些结果估计，在补充培养条件下，间型霉素B在体内将通过新型酶的作用而非包括腺苷酸琥珀酸合成酶和腺苷酸琥珀酸裂解酶的酶系统的作用转化为间型霉素。
