The Barnett Institute and Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, USA.
J Am Chem Soc. 2010 Mar 24;132(11):3642-3. doi: 10.1021/ja908995p.
S-adenosylmethionine (AdoMet or SAM)-dependent methyltransferases belong to a large and diverse family of group-transfer enzymes that perform vital biological functions on a host of substrates. Despite the progress in genomics, structural proteomics, and computational biology, functional annotation of methyltransferases remains a challenge. Herein, we report the synthesis and activity of a new AdoMet analogue functionalized with a ketone group. Using catechol O-methyltransferase (COMT, EC 2.1.1.6) and thiopurine S-methyltransferase (TPMT, EC 2.1.1.67) as model enzymes, this robust and readily accessible analogue displays kinetic parameters that are comparable to AdoMet and exhibits multiple turnovers with enzyme. More importantly, this AdoMet surrogate displays the same substrate specificity as the natural methyl donor. Incorporation of the ketone group allows for subsequent modification via bio-orthogonal labeling strategies and sensitive detection of the tagged ketone products. Hence, this AdoMet analogue expands the toolbox available to interrogate the biochemical functions of methyltransferases.
S-腺苷甲硫氨酸（AdoMet 或 SAM）依赖性甲基转移酶属于一大类具有多种功能的基团转移酶家族，可在多种底物上发挥重要的生物学功能。尽管基因组学、结构蛋白质组学和计算生物学取得了进展，但甲基转移酶的功能注释仍然是一个挑战。在此，我们报告了一种新的 AdoMet 类似物的合成和活性，该类似物带有一个酮基团。使用儿茶酚-O-甲基转移酶（COMT，EC 2.1.1.6）和硫嘌呤 S-甲基转移酶（TPMT，EC 2.1.1.67）作为模型酶，这种稳健且易于获得的类似物显示出与 AdoMet 相当的动力学参数，并与酶发生多次周转。更重要的是，这种 AdoMet 类似物具有与天然甲基供体相同的底物特异性。酮基团的引入允许通过生物正交标记策略进行后续修饰，并对标记的酮产物进行灵敏检测。因此，这种 AdoMet 类似物扩展了可用于研究甲基转移酶生化功能的工具包。
