Coenzyme engineering of a hyperthermophilic 6-phosphogluconate dehydrogenase from NADP<sup>+</sup> to NAD<sup>+</sup> with its application to biobatteries [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Energy Efficiency and Renewable Energy, 2016. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- Article numbers 36,311 : digital, PDF file
- Additional Creators:
- Virginia Polytechnic Institute and State University, United States. Department of Energy. Office of Energy Efficiency and Renewable Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- Engineering the coenzyme specificity of redox enzymes plays an important role in metabolic engineering, synthetic biology, and biocatalysis, but it has rarely been applied to bioelectrochemistry. Here we develop a rational design strategy to change the coenzyme specificity of 6-phosphogluconate dehydrogenase (6PGDH) from a hyperthermophilic bacterium <i>Thermotoga maritima</i> from its natural coenzyme NADP<sup>+</sup> to NAD<sup>+</sup>. Through amino acid-sequence alignment of NADP<sup>+</sup>- and NAD<sup>+</sup>-preferred 6PGDH enzymes and computer-aided substrate-coenzyme docking, the key amino acid residues responsible for binding the phosphate group of NADP<sup>+</sup> were identified. Four mutants were obtained via site-directed mutagenesis. The best mutant N32E/R33I/T34I exhibited a ~6.4 × 10<sup>4</sup>-fold reversal of the coenzyme selectivity from NADP<sup>+</sup> to NAD<sup>+</sup>. The maximum power density and current density of the biobattery catalyzed by the mutant were 0.135 mW cm<sup>-2</sup> and 0.255 mA cm<sup>-2</sup>, ~25% higher than those obtained from the wide-type 6PGDH-based biobattery at the room temperature. By using this 6PGDH mutant, the optimal temperature of running the biobattery was as high as 65 °C, leading to a high power density of 1.75 mW cm<sup>-2</sup>. As a result, this study demonstrates coenzyme engineering of a hyperthermophilic 6PGDH and its application to high-temperature biobatteries.
- Published through SciTech Connect., 11/02/2016., ": BFsrep36311", Scientific Reports 6 1 ISSN 2045-2322 AM, and Hui Chen; Zhiguang Zhu; Rui Huang; Yi-Heng Percival Zhang.
- Funding Information:
View MARC record | catkey: 23493278