Siegrist Jutta, Aschwanden Simon, Mordhorst Silja, Thöny-Meyer Linda, Richter Michael, Andexer Jennifer N
Institute of Pharmaceutical Sciences, University of Freiburg, Albertstrasse 25, 79104, Freiburg, Germany.
Laboratory for Biointerfaces, Empa. Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland.
Chembiochem. 2015 Dec;16(18):2576-9. doi: 10.1002/cbic.201500410. Epub 2015 Nov 6.
S-Adenosylmethionine (SAM)-dependent enzymes have great potential for selective alkylation processes. In this study we investigated the regiocomplementary O-methylation of catechols. Enzymatic methylation is often hampered by the need for a stoichiometric supply of SAM and the inhibitory effect of the SAM-derived byproduct on most methyltransferases. To counteract these issues we set up an enzyme cascade. Firstly, SAM was generated from l-methionine and ATP by use of an archaeal methionine adenosyltransferase. Secondly, 4-O-methylation of the substrates dopamine and dihydrocaffeic acid was achieved by use of SafC from the saframycin biosynthesis pathway in 40-70 % yield and high selectivity. The regiocomplementary 3-O-methylation was catalysed by catechol O-methyltransferase from rat. Thirdly, the beneficial influence of a nucleosidase on the overall conversion was demonstrated. The results of this study are important milestones on the pathway to catalytic SAM-dependent alkylation processes.
S-腺苷甲硫氨酸（SAM）依赖性酶在选择性烷基化过程中具有巨大潜力。在本研究中，我们研究了儿茶酚的区域互补性O-甲基化。酶促甲基化常常受到需要化学计量供应SAM以及SAM衍生副产物对大多数甲基转移酶的抑制作用的阻碍。为了应对这些问题，我们建立了一个酶级联反应。首先，利用古菌甲硫氨酸腺苷转移酶从L-甲硫氨酸和ATP生成SAM。其次，通过使用来自沙弗霉素生物合成途径的SafC，底物多巴胺和二氢咖啡酸的4-O-甲基化以40-70％的产率和高选择性实现。大鼠的儿茶酚O-甲基转移酶催化区域互补性的3-O-甲基化。第三，证明了核苷酶对整体转化的有益影响。本研究结果是通向催化SAM依赖性烷基化过程道路上的重要里程碑。
