Direct conversion of glucose to malate by synthetic metabolic engineering
Direct conversion of glucose to malate by synthetic metabolic engineering
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DOI：
10.1016/j.jbiotec.2012.11.011
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发表时间：
2013-03-10
影响因子：
4.1
通讯作者：
Ohtake, Hisao
中科院分区：
文献类型：
--
作者：
Ye, Xiaoting;Honda, Kohsuke;Ohtake, Hisao
合成代谢工程使我们能够构建一个专门用于化学制造的体外人工合成途径，通过简单的热处理的重组嗜温菌具有嗜热酶，然后通过合理的组合这些生物催化模块。在这项工作中，我们构建了一个合成途径，能够直接转化葡萄糖为苹果酸。Kodakarensis产苹果酸酶催化丙酮酸可逆羧化反应的研究（Δ G度' = +7.3 kJ mol（-1））与代谢上有利的非ATP形成的Embden-Meyerhof途径相结合，以平衡氧化还原辅因子的消耗和再生，并将整体平衡向苹果酸产生转移（葡萄糖+2HCO（3）（-）+2H-2苹果酸+2H（2）O; Δ G度= -121.4 kJ mol（-1））。TkME表现出丙酮酸羧化（苹果酸形成）和丙酮酸还原（乳酸形成）活性。通过增加HCO 3-浓度，反应特异性可以重定向到苹果酸生产。结果，实现了葡萄糖直接转化为苹果酸，摩尔产率为60%。(C)2012爱思唯尔有限公司版权所有。
Synthetic metabolic engineering enables us to construct an in vitro artificial synthetic pathways specialized for chemical manufacturing through the simple heat-treatment of the recombinant mesophiles having thermophilic enzymes, followed by rational combination of those biocatalytic modules. In this work, we constructed a synthetic pathway capable of direct conversion of glucose to malate. The reversible carboxylation of pyruvate catalyzed by a malic enzyme derived from Thermococcus kodakarensis (TkME) (Delta G degrees' = +7.3 kJ mol(-1)) was coupled with a thermodynamically favorable non-ATP-forming Embden-Meyerhof pathway to balance the consumption and regeneration of redox cofactors and to shift the overall equilibrium toward malate production (glucose + 2HCO(3)(-) + 2H -> 2 malate + 2H(2)O; Delta G degrees' = -121.4 kJ mol(-1)). TkME exhibited both pyruvate carboxylation (malate-forming) and pyruvate reduction (lactate-forming) activities. By increasing HCO3- concentration, the reaction specificity could be redirected to malate production. As a result, the direct conversion of glucose to malate was achieved with a molar yield of 60%. (C) 2012 Elsevier B.V. All rights reserved.