Photoinduced monooxygenation involving NAD(P)H-FAD sequential single-electron transfer
Photoinduced monooxygenation involving NAD(P)H-FAD sequential single-electron transfer
复制标题
NAD(P)H-FAD顺序单电子转移的光致单氧化
DOI：
10.1038/s41467-020-16450-y
复制
发表时间：
2020-05-25
影响因子：
16.6
通讯作者：
Drees, Steffen L.
中科院分区：
文献类型：
--
作者：
Ernst, Simon;Rovida, Stefano;Drees, Steffen L.
光依赖性或光刺激催化为技术或生物医学应用中的实施提供了多种视角。尽管光生物催化领域取得了实质性进展，但可用的光响应酶的数量仍然非常有限。黄素蛋白在光催化应用方面具有特殊的潜力，因为其命名的辅助因子本质上具有光依赖性反应性，可与各种有机电子供体进行光还原。然而，在绝大多数这些酶中，酶结合黄素的光反应性受到限制甚至被抑制。在这里，我们提出了一种黄素蛋白单加氧酶，其中催化活性可通过蓝光照明控制。该反应取决于烟酰胺核苷酸型电子供体的存在，在没有光的情况下不支持该反应。采用各种实验方法，我们证明催化作用取决于蛋白质介导的黄素辅助因子的光还原，该还原通过自由基机制和瞬时半醌中间体进行。尽管具有潜在的生物技术应用，但可用的光响应酶的数量是有限的。在这里，作者报道了一种可通过蓝光照明控制的黄素蛋白单加氧酶，并提出了一种涉及通过半醌中间体进行蛋白质介导的 FAD 自由基光还原的机制。
Light-dependent or light-stimulated catalysis provides a multitude of perspectives for implementation in technological or biomedical applications. Despite substantial progress made in the field of photobiocatalysis, the number of usable light-responsive enzymes is still very limited. Flavoproteins have exceptional potential for photocatalytic applications because the name-giving cofactor intrinsically features light-dependent reactivity, undergoing photoreduction with a variety of organic electron donors. However, in the vast majority of these enzymes, photoreactivity of the enzyme-bound flavin is limited or even suppressed. Here, we present a flavoprotein monooxygenase in which catalytic activity is controllable by blue light illumination. The reaction depends on the presence of nicotinamide nucleotide-type electron donors, which do not support the reaction in the absence of light. Employing various experimental approaches, we demonstrate that catalysis depends on a protein-mediated photoreduction of the flavin cofactor, which proceeds via a radical mechanism and a transient semiquinone intermediate. The number of usable light-responsive enzymes is limited, despite the potential biotechnological applications. Here, the authors report a flavoprotein monooxygenase which is controllable by blue light illumination, and propose a mechanism involving protein-mediated radical photoreduction of FAD via a semiquinone intermediate.