Chair of Chemistry of Biogenic Resources, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Schulgasse 16, 94315, Straubing, Germany.
TUM Catalysis Research Center, Technical University of Munich, Ernst-Otto-Fischer-Straße 1, 85748, Garching, Germany.
Chembiochem. 2020 Nov 16;21(22):3273-3281. doi: 10.1002/cbic.202000378. Epub 2020 Aug 5.
Propene is one of the most important starting materials in the chemical industry. Herein, we report an enzymatic cascade reaction for the biocatalytic production of propene starting from n-butanol, thus offering a biobased production from glucose. In order to create an efficient system, we faced the issue of an optimal cofactor supply for the fatty acid decarboxylase OleT , which is said to be driven by either NAD(P)H or H O . In the first system, we used an alcohol and aldehyde dehydrogenase coupled to OleT by the electron-transfer complex putidaredoxin reductase/putidaredoxin, allowing regeneration of the NAD cofactor. With the second system, we intended full oxidation of n-butanol to butyric acid, generating one equivalent of H O that can be used for the oxidative decarboxylation. As the optimal substrate is a long-chain fatty acid, we also tried to create an improved variant for the decarboxylation of butyric acid by using rational protein design. Within a mutational study with 57 designed mutants, we generated the mutant OleT , which showed a 2.4-fold improvement in propene production in our H O -driven cascade system and reached total turnover numbers >1000.
丙烯是化学工业中最重要的原料之一。在此，我们报告了一种酶级联反应，用于从正丁醇生物催化生产丙烯，从而提供了从葡萄糖生物基生产丙烯的方法。为了创建一个有效的系统，我们面临着脂肪酸脱羧酶 OleT 的最佳辅因子供应问题，据说该酶由 NAD(P)H 或 H2O 驱动。在第一个系统中，我们使用与 OleT 偶联的醇和醛脱氢酶，通过电子转移复合物 putidaredoxin 还原酶/putidaredoxin 进行再生，允许 NAD 辅因子的再生。在第二个系统中，我们旨在将正丁醇完全氧化为丁酸，生成一个当量的 H2O，可用于氧化脱羧。由于最佳底物是长链脂肪酸，我们还试图通过合理的蛋白质设计为丁酸脱羧创造一种改进的变体。在一项针对 57 个设计突变体的突变研究中，我们生成了突变体 OleT，该突变体在我们的 H2O 驱动级联系统中提高了 2.4 倍的丙烯产量，总周转率数>1000。
