Mehta J R, Ludlum D B
Biochim Biophys Acta. 1978 Dec 21;521(2):770-8. doi: 10.1016/0005-2787(78)90316-7.
This paper describes the synthesis of O6-methyldeoxyguanosine triphosphate (m6dGTP) and its copolymerization to high molecular weight polymer with deoxycytidylic acid. The monomer, m6dGTP, was synthesized from deoxyguanosine first protected by acetylation of the sugar hydroxyls, and then chlorinated in the 6-position with POCl3. The product, 6-chloro-3',5'-di-O-acetyl deoxyguanosine, was converted to O6-methyldeoxyguanosine with sodium methoxide and phosphorylated in the 5' position with carrot phosphotransferase. Monophosphate was converted chemically to the triphosphate and copolymerized with dCTP by terminal deoxynucleotidyl transferase. The resulting template, which contained O6-methylguanine, was tested for its ability to direct RNA synthesis by bacterial RNA polymerase. The presence of O6-methylguanine was shown to lead to the misincorporation of UMP in the product polymer, thus strengthening the hypothesis that O6-methylguanine is a promutagenic base.
本文描述了O6-甲基脱氧鸟苷三磷酸（m6dGTP）的合成及其与脱氧胞苷酸共聚合成高分子量聚合物的过程。单体m6dGTP是由首先通过糖羟基乙酰化进行保护的脱氧鸟苷合成的，然后用三氯氧磷在6位进行氯化。产物6-氯-3'，5'-二-O-乙酰基脱氧鸟苷用甲醇钠转化为O6-甲基脱氧鸟苷，并通过胡萝卜磷酸转移酶在5'位进行磷酸化。单磷酸通过化学方法转化为三磷酸，并通过末端脱氧核苷酸转移酶与dCTP共聚。所得含有O6-甲基鸟嘌呤的模板，经测试其指导细菌RNA聚合酶进行RNA合成的能力。结果表明，O6-甲基鸟嘌呤的存在导致产物聚合物中UMP的错误掺入，从而强化了O6-甲基鸟嘌呤是一种促变碱基的假说。
