Interdisciplinary Program of Bioenergy and Biomaterial Engineering, Chonnam National University, Gwangju 500-757, Korea.
J Microbiol Biotechnol. 2012 Oct;22(10):1446-51. doi: 10.4014/jmb.1206.06043.
Levodopa or L-3,4-dihydroxyphenylalanine (L-DOPA) is the precursor of the neurotransmitter dopamine. L-DOPA is a famous treatment for Parkinson's disease symptoms. In this study, electroenzymatic synthesis of L-DOPA was performed in a three-electrode cell, comprising a Ag/AgCl reference electrode, a platinum wire auxiliary electrode, and a glassy carbon working electrode. L-DOPA had an oxidation peak at 376 mV and a reduction peak at -550 mV. The optimum conditions of pH, temperature, and amount of free tyrosinase enzyme were pH 7, 30 degrees C, and 250 IU, respectively. The kinetic constant of the free tyrosinase enzyme was found for both cresolase and catacholase activity to be 0.25 and 0.4 mM, respectively. A cyclic voltammogram was used to investigate the electron transfer rate constant. The mean heterogeneous electron transfer rate (ke) was 5.8 × 10(-4) cm/s. The results suggest that the electroenzymatic method could be an alternative way to produce L-DOPA without the use of a reducing agent such as ascorbic acid.
左旋多巴或 L-3,4-二羟基苯丙氨酸（L-DOPA）是神经递质多巴胺的前体。L-DOPA 是治疗帕金森病症状的著名药物。在这项研究中，在三电极电池中进行了 L-DOPA 的电酶合成，该电池由 Ag/AgCl 参比电极、铂丝辅助电极和玻碳工作电极组成。L-DOPA 的氧化峰在 376 mV，还原峰在-550 mV。最佳条件为 pH 7、30°C 和游离酪氨酸酶酶量 250 IU。游离酪氨酸酶的动力学常数对于愈创木酚酶和儿茶酚酶活性分别为 0.25 和 0.4 mM。循环伏安法用于研究电子转移速率常数。平均非均相电子转移速率（ke）为 5.8×10(-4)cm/s。结果表明，电酶法可以替代不使用抗坏血酸等还原剂来生产 L-DOPA。
