Department of Pharmaceutical and Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China.
Department of Pharmaceutical and Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China.
J Inorg Biochem. 2022 Sep;234:111878. doi: 10.1016/j.jinorgbio.2022.111878. Epub 2022 May 29.
L-3,4-dihydroxyphenylalanine (L-DOPA) is in high demand as the cornerstone for treatment of Parkinson's disease. The current production of L-DOPA is associated with poor productivity and long production period. Biomimetic system inspired from tyrosine hydroxylase was developed to achieve the production of L-DOPA from tyrosine with high reactivity, efficiency, and specificity. The biomimetic system owned close resemblance of component and structure in comparison with tyrosine hydroxylase, consisting of tyrosine as substrate, a redox complex of Fe and EDTA as the catalyst to simulate the active center of the natural tyrosine hydroxylase, hydrogen peroxide as the oxidant, and ascorbic acid as the reductant. HPLC, HPLC-MS/MS, H NMR, and specific rotation identified L-DOPA was generated. The system showed high catalytic activity and regioselectivity for hydroxylation of tyrosine as equal to tyrosine hydroxylase. FeO was formed as the major active species, and NIH shift was observed. EDTA accelerated the reaction by reducing the redox potential of Fe/Fe couple. Density functional theory calculation suggested formation of FeO was more thermodynamically favorable. The biomimetic system shared analogous catalytic mechanism with TyrH. Process parameters was optimized for maximum production of L-DOPA, namely 6.4 mM tyrosine, 1.6 mM Fe, 1.92 mM EDTA, 150 mM HO, and 35 mM ascorbic acid in 0.2 M glycine-HCl buffer at pH 4.5 and 60 °C. The yield, titer, and productivity were obtained as 52.01%, 3.22 mM, and 48,210.68 mg L h, respectively. The proposed method exhibited an amazing productivity, might provide a promising strategy to industrialize L-DOPA production.
L-3,4-二羟基苯丙氨酸（L-DOPA）是治疗帕金森病的基石，需求量很大。目前 L-DOPA 的生产与低生产率和长生产周期有关。受酪氨酸羟化酶启发的仿生系统被开发出来，以实现从酪氨酸高效、高特异性地生产 L-DOPA。与酪氨酸羟化酶相比，仿生系统在组成和结构上都非常相似，它由酪氨酸作为底物，Fe 和 EDTA 的氧化还原复合物作为催化剂模拟天然酪氨酸羟化酶的活性中心，过氧化氢作为氧化剂，抗坏血酸作为还原剂。通过 HPLC、HPLC-MS/MS、1H NMR 和比旋光度鉴定生成了 L-DOPA。该系统对酪氨酸的羟化具有与酪氨酸羟化酶相当的高催化活性和区域选择性。形成了主要的活性物种 FeO，并观察到 NIH 位移。EDTA 通过降低 Fe/Fe 对的氧化还原电位来加速反应。密度泛函理论计算表明，FeO 的形成在热力学上更有利。仿生系统与 TyrH 具有类似的催化机制。优化了工艺参数以实现 L-DOPA 的最大产量，即在 0.2 M 甘氨酸-HCl 缓冲液（pH 4.5 和 60°C）中，使用 6.4 mM 酪氨酸、1.6 mM Fe、1.92 mM EDTA、150 mM HO 和 35 mM 抗坏血酸。获得的产率、浓度和生产率分别为 52.01%、3.22 mM 和 48,210.68 mg L-1 h-1。该方法表现出惊人的生产率，可能为 L-DOPA 的工业化生产提供了一种有前途的策略。
