Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka, Japan.
FEMS Microbiol Lett. 2011 Jan;314(2):164-9. doi: 10.1111/j.1574-6968.2010.02158.x. Epub 2010 Nov 30.
Aflatoxin B(1) (AFB(1) ) is a potent mycotoxin with mutagenic, carcinogenic, teratogenic, hepatotoxic, and immunosuppressive properties. In order to develop a bioremediation system for AFB(1) -contaminated foods by white-rot fungi or ligninolytic enzymes, AFB(1) was treated with manganese peroxidase (MnP) from the white-rot fungus Phanerochaete sordida YK-624. AFB(1) was eliminated by MnP. The maximum elimination (86.0%) of AFB(1) was observed after 48 h in a reaction mixture containing 5 nkat of MnP. The addition of Tween 80 enhanced AFB(1) elimination. The elimination of AFB(1) by MnP considerably reduced its mutagenic activity in an umu test, and the treatment of AFB(1) by 20 nkat MnP reduced the mutagenic activity by 69.2%. (1) H-NMR and HR-ESI-MS analysis suggested that AFB(1) is first oxidized to AFB(1) -8,9-epoxide by MnP and then hydrolyzed to AFB(1) -8,9-dihydrodiol. This is the first report that MnP can effectively remove the mutagenic activity of AFB(1) by converting it into AFB(1) -8,9-dihydrodiol.
黄曲霉毒素 B(1)（AFB(1)）是一种具有诱变、致癌、致畸、肝毒性和免疫抑制特性的强效真菌毒素。为了开发一种通过白腐真菌或木质素降解酶对受 AFB(1)污染的食品进行生物修复的系统，用来自白腐真菌 Phanerochaete sordida YK-624 的锰过氧化物酶（MnP）处理 AFB(1)。MnP 消除了 AFB(1)。在含有 5 nkat MnP 的反应混合物中，48 h 后 AFB(1)的最大消除率（86.0%）。添加吐温 80 增强了 AFB(1)的消除。MnP 对 AFB(1)的消除大大降低了其在 umu 测试中的致突变活性，而 20 nkat MnP 处理 AFB(1)使其致突变活性降低了 69.2%。（1）H-NMR 和 HR-ESI-MS 分析表明，MnP 首先将 AFB(1)氧化为 AFB(1)-8,9-环氧化物，然后水解为 AFB(1)-8,9-二氢二醇。这是 MnP 通过将其转化为 AFB(1)-8,9-二氢二醇有效去除 AFB(1)致突变活性的首次报道。
