S-adenosyl-L-methionine

• 分子结构分类: 有机化合物 - 核苷、核苷酸和类似物 - 5'-脱氧核糖核苷
• 英文名称: S-adenosyl-L-methionine
• 英文别名: s-Adenosyl-d-methionine；(2R)-2-amino-4-[[(2S,3S,4R,5R)-5-(6-aminopurin-9-yl)-3,4-dihydroxyoxolan-2-yl]methyl-methylsulfonio]butanoate
• 化学式: C₁₅H₂₂N₆O₅S
• 分子量: 398.443
• InChiKey: MEFKEPWMEQBLKI-XCPQSEKJSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -2.8
• 重原子数：
  27
• 可旋转键数：
  6
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.6
• 拓扑面积：
  187
• 氢给体数：
  4
• 氢受体数：
  10

反应信息

• 作为反应物：
  描述：

  S-adenosyl-L-methionine 、 2-巯基吡嗪 在 rat liver microsomes 作用下， 以 phosphate buffer 为溶剂， 反应 0.5h， 生成 2-甲硫基吡嗪
  参考文献：
  名称：

  S-methylation of 2-mercaptopyrazine in rat liver microsomes and cytosol

  摘要：

  1. 2-(Allylthio)pyrazine (2-AP) has been demonstrated to protect the liver against toxicants by inhibiting CYP2E1 activity. Since 2-mercaptopyrazine (2-MP) is presumed to be a metabolite of 2-AP, the experiments were performed to determine whether rat liver microsomal and/or cytosolic preparations could catalyse the S-methylation of 2-MP.2. It was found that both rat liver microsomes and cytosol could catalyse the S-methylation of 2-MP. The microsomal activity displayed biphasic substrate kinetics, with apparent K-m = 8.44+/-2.68 and 417+/-74 mu M for the high- and low-affinity activities respectively. The high-affinity activity had an apparent K-m for S-adenosyl-L-methionine (Ado-Met) of 3.52 mu M. The cytosolic activity also displayed biphasic substrate kinetics, with apparent K-m of 3.26+/-0.62 and 91.6+/-23.1 mu M for the high- and low-affinity activities respectively.3. The microsomal S-methylation of 2-MP was inhibited by 2,3-dichloro-alpha-methylbenzylamine (DCMB), SKF-525A and benzylamine, known microsomal thiol methyltransferase (TMT) inhibitors, whereas cytosolic activity was inhibited by anisic acid and 3-chlorobenzoate, which also inhibit cytosolic thiopurine methyltransferase (TPMT). Both activities were inhibited by S-adenosyr-L-homocysteine (Met-Hcy).4. These results suggest that both TMT and TPMT may be involved in the in vivo methylation of 2-MP.

  DOI：

  10.1080/004982599238155