AbstractEnzyme‐catalyzed late‐stage functionalization (LSF), such as methylation of drug molecules and lead structures, enables direct access to more potent active pharmaceutical ingredients (API). S‐adenosyl‐l‐methionine‐dependent methyltransferases (MTs) can play a key role in the development of new APIs, as they catalyze the chemo‐ and regioselective methylation of O‐, N‐, S‐ and C‐atoms, being superior to traditional chemical routes. To identify suitable MTs, we developed a continuous fluorescence‐based, high‐throughput assay for SAM‐dependent methyltransferases, which facilitates screening using E. coli cell lysates. This assay involves two enzymatic steps for the conversion of S‐adenosyl‐l‐homocysteine into H2S to result in a selective fluorescence readout via reduction of an azidocoumarin sulfide probe. Investigation of two O‐MTs and an N‐MT confirmed that this assay is suitable for the determination of methyltransferase activity in E. coli cell lysates.
摘要酶催化的后期功能化(LSF),如药物分子和先导结构的甲基化,可以直接获得更有效的活性药物成分(API)。依赖于 S-腺苷-l-蛋氨酸的甲基转移酶(MTs)能催化 O 原子、N 原子、S 原子和 C 原子的化学和区域选择性甲基化,优于传统的化学途径,因此能在新原料药的开发中发挥关键作用。为了确定合适的 MT,我们开发了一种基于荧光的连续高通量检测方法,用于检测依赖于 SAM 的甲基转移酶,这种方法便于使用大肠杆菌细胞裂解液进行筛选。这种检测方法包括两个酶促步骤,将 S-腺苷-l-高半胱氨酸转化为 H2S,通过还原叠氮香豆素硫化物探针产生选择性荧光读数。对两种 O-甲基半胱氨酸和一种 N-甲基半胱氨酸的研究证实,这种检测方法适用于测定大肠杆菌细胞裂解物中的甲基转移酶活性。