Ethylation of poly(dC-dG).poly(dC-dG) by ethyl methanesulfonate stimulates the activity of mammalian DNA methyltransferase in vitro.
Ethylation of poly(dC-dG).poly(dC-dG) by ethyl methanesulfonate stimulates the activity of mammalian DNA methyltransferase in vitro.
复制标题
甲磺酸乙酯对聚 (dC-dG).聚 (dC-dG) 的乙基化可在体外刺激哺乳动物 DNA 甲基转移酶的活性。
DOI：
10.1073/pnas.82.4.1045
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发表时间：
1985
影响因子：
11.1
通讯作者：
Ivarie,R
中科院分区：
文献类型：
--
作者：
Farrance,IK;Ivarie,R
聚（dC-dG）.聚（dC-dG）与已知致癌物甲磺酸乙酯（EtMes）的乙基化，在EtMes/C X G碱基对摩尔比不断增加的情况下，在体外甲基化过程中，通过部分纯化的大鼠DNA（cytosine-5）-甲基转移酶（EC 2.1.1.37）逐渐刺激DNA的甲基接受能力。当2.7%的鸟嘌呤在N-7位（DNA中EtMes乙基化的主要位点）被修饰时，最大刺激是模拟处理的DNA的2倍。如果在鸟嘌呤N-7处的CpG位点“半甲基化”模拟半甲基化的CpG位点，我们计算出该酶对半甲基化的CpG的相对亲和力是未修饰的CpG的18倍。如果磷酸二酯键的二氧磷酸氧的乙基化是刺激的原因，则相对亲和力可能高得多，高达370倍。
Ethylation of poly(dC-dG).poly(dC-dG) with ethyl methanesulfonate (EtMes), a known carcinogen, at increasing molar ratios of EtMes/C X G base pairs progressively stimulated the methyl-accepting ability of the DNA during in vitro methylation by partially purified rat DNA (cytosine-5)-methyltransferase (EC 2.1.1.37). Maximum stimulation was 2-fold over mock-treated DNA when 2.7% of the guanines were modified at the N-7 position, the major site of ethylation by EtMes in DNA. If a CpG site "hemiethylated" at guanine N-7 mimics a hemimethylated CpG site, we calculate that the enzyme has a relative affinity for hemiethylated CpG 18-fold above unmodified CpG. If ethylation of a dioxyphosphate oxygen of the phosphodiester bond is responsible for stimulation, the relative affinity could be much higher, up to 370-fold.