Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science and Bioengineering , Beijing University of Technology , 100 Ping Le Yuan, Chaoyang District , Beijing 100124 , China.
College of Life Science and Bioengineering , Beijing University of Technology , 100 Ping Le Yuan, Chaoyang District , Beijing 100124 , China.
ACS Chem Neurosci. 2018 Jun 20;9(6):1388-1398. doi: 10.1021/acschemneuro.8b00023. Epub 2018 Apr 12.
Salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline), a derivate of dopamine, is suspected to be the most probable neurotoxin in the degeneration of dopaminergic neurons. Numerous hypotheses regarding its pathophysiological roles have been raised, especially related to Parkinson's disease and alcohol addiction. In the mammalian brain, salsolinol may be enzymatically synthesized by salsolinol synthase from dopamine and acetaldehyde. However, the direct evidence of its biosynthesis was still missing. In this study, we purified salsolinol synthase from rat brain by a systematical procedure involving acid precipitation, ultrafiltration, and hydrophilic interaction chromatography. The molecular weight of salsolinol synthase determined by MALDI-TOF MS is 8622.29 Da, comprising 77 amino acids (MQIFVKTLTG KTITLEVEPS DTIKNVKAKI QDKEGIPPDQ QRLIFAGKQL EDGRTLSDYN IQKKSTLHLV LRLRVDY). Homology analysis showed that the enzyme is a ubiquitin-like protein, with a difference of four amino acids, which suggests it is a novel protein. After it was overexpressed in eukaryotic cells, the production of salsolinol was significantly increased as compared with control, confirming the catalytic function of this enzyme. To our knowledge, it is the first systematic purification and sequencing of salsolinol synthase. Together, this work reveals a formerly anonymous protein and urges further exploration of its possible prognostic value and implications in Parkinson's disease and other related disorders.
萨尔索林醇（1-甲基-6,7-二羟基-1,2,3,4-四氢异喹啉），一种多巴胺的衍生物，被怀疑是多巴胺能神经元退化过程中最有可能的神经毒素。人们提出了许多关于其病理生理作用的假设，特别是与帕金森病和酒精成瘾有关的假设。在哺乳动物的大脑中，萨尔索林醇可能由多巴胺和乙醛通过萨尔索林醇合酶酶促合成。然而，其生物合成的直接证据仍然缺失。在这项研究中，我们通过涉及酸沉淀、超滤和亲水性相互作用色谱的系统程序从大鼠脑中纯化了萨尔索林醇合酶。MALDI-TOF MS 测定的萨尔索林醇合酶分子量为 8622.29 Da，由 77 个氨基酸组成（MQIFVKTLTG KTITLEVEPS DTIKNVKAKI QDKEGIPPDQ QRLIFAGKQL EDGRTLSDYN IQKKSTLHLV LRLRVDY）。同源性分析表明，该酶是一种泛素样蛋白，仅相差四个氨基酸，提示它是一种新型蛋白。在真核细胞中过表达后，与对照相比，萨尔索林醇的产量明显增加，证实了该酶的催化功能。据我们所知，这是萨尔索林醇合酶的首次系统纯化和测序。总之，这项工作揭示了一种以前未知的蛋白质，并促使进一步探索其在帕金森病和其他相关疾病中的可能预后价值和意义。
