Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, 8010, Graz, Austria.
Austrian Centre of Industrial Biotechnology (acib), Petersgasse 14, 8010, Graz, Austria.
Chemistry. 2020 Dec 4;26(68):15910-15921. doi: 10.1002/chem.201905511. Epub 2020 Oct 27.
Oxyfunctionalization of fatty acids (FAs) is a key step in the design of novel synthetic pathways for biobased/biodegradable polymers, surfactants and fuels. Here, we show the isolation and characterization of a robust FA α-hydroxylase (P450 ) which catalyses the selective conversion of a broad range of FAs (C6:0-C16:0) and oleic acid (C18:1) with H O as oxidant. Under optimized reaction conditions P450 yields α-hydroxy acids all with >95 % regioselectivity, high specific activity (up to 15.2 U mg ) and efficient coupling of oxidant to product (up to 85 %). Lauric acid (C12:0) turned out to be an excellent substrate with respect to productivity (TON=394 min ). On preparative scale, conversion of C12:0 reached 83 % (0.9 g L ) when supplementing H O in fed-batch mode. Under similar conditions P450 allowed further the first biocatalytic α-hydroxylation of oleic acid (88 % conversion on 100 mL scale) at high selectivity and in good yields (1.1 g L ; 79 % isolated yield). Unexpectedly, P450 displayed also 1-alkene formation from shorter chain FAs (≤C10:0) showing that oxidative decarboxylation is more widely distributed across this enzyme family than reported previously.
脂肪酸（FAs）的氧化功能化是设计新型生物基/可生物降解聚合物、表面活性剂和燃料合成途径的关键步骤。在这里，我们展示了一种强大的 FA α-羟化酶（P450）的分离和表征，该酶能够催化广泛的 FAs（C6:0-C16:0）和油酸（C18:1）与 H2O2作为氧化剂的选择性转化。在优化的反应条件下，P450 以>95%的区域选择性、高比活性（高达 15.2 U mg-1）和氧化剂与产物的有效偶联（高达 85%）生成α-羟基酸。对于生产力（TON=394 min-1）而言，月桂酸（C12:0）是一种极好的底物。在制备规模上，当以补料分批模式补充 H2O2 时，C12:0 的转化率达到 83%（0.9 g L-1）。在类似的条件下，P450 还允许油酸（100 mL 规模上的转化率为 88%）的首次生物催化α-羟化，具有高选择性和良好的收率（1.1 g L-1；79%的分离收率）。出乎意料的是，P450 还显示出较短链 FAs（≤C10:0）的 1-烯形成，表明氧化脱羧作用在该酶家族中的分布比以前报道的更为广泛。
