Type II Flavin-Containing Monooxygenases: A New Class of Biocatalysts that Harbors Baeyer-Villiger Monooxygenases with a Relaxed Coenzyme Specificity
作者:Anette Riebel、Michael J. Fink、Marko D. Mihovilovic、Marco W. Fraaije
DOI:10.1002/cctc.201300550
日期:2014.4
type II FMOs follow a catalytic mechanism similar to that of other class B flavoprotein monooxygenases. A set of cyclobutanones and cyclohexanones were used to probe the regio‐ and enantioselectivity of all three recombinant monooxygenases. The biocatalysts readily accepted small cyclic ketones, which enabled the conversion of previously poorly accepted substrates by other monooxygenases (especially
在新发现的一组红球红球菌中含有黄素的单加氧酶(FMO)中RHA1,我们已经确定了三种有效催化Baeyer-Villiger氧化的单加氧酶(FMO-E,FMO-F和FMO-G)。这些II型FMO通过接受NADPH(烟酰胺腺嘌呤二核苷酸磷酸的还原形式)和NADH(烟酰胺腺嘌呤二核苷酸磷酸的还原形式)显示出宽松的辅酶特异性,作为一种辅酶,在能够进行Baeyer–维利格氧化。我们纯化了FMO-E,并确定两种辅酶的米氏常数都在微摩尔范围内,而NADH的活性最高。通过使用停流技术,观察到过氧黄素酶中间体的形成,这表明II型FMO遵循的催化机制与其他B类黄素单加氧酶类似。使用一组环丁酮和环己酮来探测所有三种重组单加氧酶的区域和对映选择性。这种生物催化剂容易接受小的环状酮,这使得其他单加氧酶(尤其是正樟脑)可以转化以前不被广泛接受的底物,并表现出优异而独特的区域选择性和对映选择性。序列分析显示,充当Bae