Department of Chemistry and Biochemistry, UCLA-DOE Institute for Genomics and Proteomics, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA.
Nat Chem Biol. 2017 Sep;13(9):938-942. doi: 10.1038/nchembio.2418. Epub 2017 Jul 3.
Synthetic biochemistry seeks to engineer complex metabolic pathways for chemical conversions outside the constraints of the cell. Establishment of effective and flexible cell-free systems requires the development of simple systems to replace the intricate regulatory mechanisms that exist in cells for maintaining high-energy cofactor balance. Here we describe a simple rheostat that regulates ATP levels by controlling the flow down either an ATP-generating or non-ATP-generating pathway according to the free-phosphate concentration. We implemented this concept for the production of isobutanol from glucose. The rheostat maintains adequate ATP concentrations even in the presence of ATPase contamination. The final system including the rheostat produced 24.1 ± 1.8 g/L of isobutanol from glucose in 91% theoretical yield with an initial productivity of 1.3 g/L/h. The molecular rheostat concept can be used in the design of continuously operating, self-sustaining synthetic biochemistry systems.
合成生物化学寻求在细胞限制之外设计用于化学转化的复杂代谢途径。建立有效和灵活的无细胞系统需要开发简单的系统来替代细胞中存在的复杂调节机制，以维持高能辅因子平衡。在这里，我们描述了一个简单的变阻器，它通过根据游离磷酸盐浓度控制 ATP 生成或非 ATP 生成途径的流量来调节 ATP 水平。我们将这一概念应用于从葡萄糖生产异丁醇。即使存在 ATP 酶污染，变阻器也能维持足够的 ATP 浓度。最终的系统包括变阻器，从葡萄糖中生产了 24.1 ± 1.8 g/L 的异丁醇，理论得率为 91%，初始生产力为 1.3 g/L/h。分子变阻器概念可用于设计连续运行、自我维持的合成生物化学系统。
