Biological production of chemicals often requires the use of cellular cofactors, such as nicotinamide adenine dinucleotide phosphate (NADP+). These cofactors are expensive to use in vitro and difficult to control in vivo. We demonstrate the development of a noncanonical redox cofactor system based on nicotinamide mononucleotide (NMN+). The key enzyme in the system is a computationally designed glucose dehydrogenase with a 107-fold cofactor specificity switch toward NMN+ over NADP+ based on apparent enzymatic activity. We demonstrate that this system can be used to support diverse redox chemistries in vitro with high total turnover number (~39,000), to channel reducing power in Escherichia coli whole cells specifically from glucose to a pharmaceutical intermediate, levodione, and to sustain the high metabolic flux required for the central carbon metabolism to support growth. Overall, this work demonstrates efficient use of a noncanonical cofactor in biocatalysis and metabolic pathway design.

中文翻译：

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设计用于生物催化的烟酰胺单核苷酸氧化还原辅因子系统。


化学品的生物生产通常需要使用细胞辅助因子，例如烟酰胺腺嘌呤二核苷酸磷酸 (NADP+)。这些辅助因子在体外使用起来很昂贵并且在体内难以控制。我们展示了基于烟酰胺单核苷酸（NMN+）的非规范氧化还原辅因子系统的开发。该系统中的关键酶是一种经过计算设计的葡萄糖脱氢酶，根据明显的酶活性，其辅因子特异性可切换至 NMN+（而非 NADP+）。我们证明，该系统可用于在体外支持多种氧化还原化学反应，具有高总周转数（~39,000），引导大肠杆菌全细胞中的还原能力，特别是从葡萄糖到药物中间体左旋二酮，并维持高代谢中央碳代谢支持生长所需的通量。总体而言，这项工作证明了非经典辅因子在生物催化和代谢途径设计中的有效利用。