作者:Dittmar Schlieper、Wolfgang Barz
DOI:10.1016/s0031-9422(00)83862-5
日期:——
Abstract A soluble enzyme which catalyses the NADPH-dependent reduction of the heterocyclic double bond of the isoflavone biochanin A (5,7-dihydroxy-4′-methoxy-isoflavone) yielding the corresponding isoflavanone was isolated from the fungus Fusarium javanicum. The NADPH: biochanin A oxidoreductase was constitutively present in the mycelium with an extractable average activity of 4 pkat/g fresh weight. The
摘要 从真菌 Fusarium javanicum 中分离出一种可溶性酶,该酶催化异黄酮生物链素 A(5,7-二羟基-4'-甲氧基-异黄酮)的杂环双键的 NADPH 依赖性还原,产生相应的异黄烷酮。NADPH: biochanin A 氧化还原酶组成型存在于菌丝体中,可提取的平均活性为 4 pkat/g 鲜重。将酶纯化约 4500 倍至表观均一。天然酶的 Mr, 约为 87 000,由 Mr, 43 000 的两个相同亚基组成。酶反应显示最佳 pH 值为 7.5,最佳温度为 30 至 35°。biochanin A 的表观 Km 值为 43 μM,NADPH 的表观 Km 值为 190 μM,最大速度为 4 mkat/kg 蛋白质。该酶对 biochanin A 表现出显着的底物特异性。