Mathematical model of the MenD-catalyzed 1,4-addition (Stetter reaction) of α-ketoglutaric acid to acrylonitrile.
Mathematical model of the MenD-catalyzed 1,4-addition (Stetter reaction) of α-ketoglutaric acid to acrylonitrile.
复制标题
MenD 催化 α-酮戊二酸与丙烯腈 1,4-加成（Stetter 反应）的数学模型。
DOI：
10.1016/j.jbiotec.2018.01.013
复制
发表时间：
2018
影响因子：
4.1
通讯作者：
Z. Blažević
中科院分区：
文献类型：
--
作者：
M. Sudar;Đ. Vasić;Michael Müller;Alexandra Walter;Z. Blažević
Stetter反应是一种共轭聚合反应，主要用于芳香醛的氰化物催化转化。然而，酶促Stetter反应在很大程度上尚未探索，特别是在制备转化方面。我们已经研究了MenD催化的α-酮基谷氨酸与丙烯腈的1，4-加成的动力学，这表明丙烯腈虽然是一种令人感兴趣的候选物，但由于酶对该底物的亲和力低，因此是MenD的不良底物。反应动力学模型简化为双底物米氏动力学，反应速率与丙烯腈浓度呈线性关系。在不同丙烯腈初始浓度下，在间歇、重复间歇和补料间歇反应器条件下进行了实验，以验证所开发的数学模型。硫胺素二磷酸依赖性MenD被证明是相当稳健的酶;然而，在反应器中发生酶操作稳定性衰减。在数学建模过程中还考虑了丙烯腈对聚合的自发反应性。在所有间歇反应器实验中实现了丙烯腈的几乎定量转化，而所需产物的产率取决于初始丙烯腈浓度（即，稳定剂添加剂的浓度）。使用优化的反应器参数，可以合成浓度为250 mM的产物6-氰基-4-氧代己酸。在重复的间歇反应器实验中达到了最高的产物浓度。补料分批反应器实验也提供了有希望的结果，特别是关于实现200 mM产物浓度所需的短反应时间。因此，与高反应性受体底物的酶促Stetter反应可以在制备规模上进行，这应该能够与丙烯酸酯、甲基丙烯酸酯和甲基乙烯基酮进行类似的转化。
The Stetter reaction, a conjugate umpolung reaction, is well known for cyanide-catalyzed transformations of mostly aromatic aldehydes. Enzymatic Stetter reactions, however, have been largely unexplored, especially with respect to preparative transformations. We have investigated the kinetics of the MenD-catalyzed 1,4-addition of α-ketoglutaric acid to acrylonitrile which has shown that acrylonitrile, while an interesting candidate, is a poor substrate for MenD due to low affinity of the enzyme for this substrate. The kinetic model of the reaction was simplified to double substrate Michaelis–Menten kinetics where the reaction rate linearly depends on acrylonitrile concentration. Experiments at different initial concentrations of acrylonitrile under batch, repetitive batch, and fed-batch reactor conditions were carried out to validate the developed mathematical model. Thiamine diphosphate dependent MenD proved to be quite a robust enzyme; nevertheless, enzyme operational stability decay occurs in the reactor. The spontaneous reactivity of acrylonitrile towards polymerization was also taken into account during mathematical modeling. Almost quantitative conversion of acrylonitrile was achieved in all batch reactor experiments, while the yield of the desired product was dependent on initial acrylonitrile concentration (i.e., the concentration of the stabilizer additive). Using the optimized reactor parameters, it was possible to synthesize the product, 6-cyano-4-oxohexanoic acid, in a concentration of 250 mM. The highest concentration of product was achieved in a repetitive batch reactor experiment. A fed-batch reactor experiment also delivered promising results, especially regarding the short reaction time needed to achieve a 200 mM concentration of product. Hence, the enzymatic Stetter reaction with a highly reactive acceptor substrate can be performed on a preparative scale, which should enable similar transformations with acrylate, methacrylate, and methyl vinyl ketone.
定制大肠杆菌 2â琥珀酰â5â烯醇丙酮酰â6â羟基â3â环己烯â1â羧酸合酶 (MenD) 的 Sâ选择性
影响因子：
4.5
作者：
Westphal R;Hahn D;Mackfeld U;Waltzer S;Beigi M;Widmann M;Vogel C;Pleiss J;Müller M;Pohl M
通讯作者：
Pohl M
丙烯腈体外代谢为2-氰基环氧乙烷，与谷胱甘肽反应，与蛋白质和核酸不可逆结合。
影响因子：
11.2
作者：
Guengerich,FP;Geiger,LE;Hogy,LL;Wright,PL
通讯作者：
Wright,PL
影响因子：
16.6
作者：
Bongaerts, Johannes;Esser, Simon;Mueller, Michael
通讯作者：
Mueller, Michael