Lyon S B, Buonocore L, Miller M
Mol Cell Biol. 1987 May;7(5):1759-63. doi: 10.1128/mcb.7.5.1759-1763.1987.
A naturally occurring methylation inhibitor isolated from rabbit liver and named methinin inhibits a number of methyltransferases. Methinin is a low-molecular-weight compound (1,400) that has an active amine group. This compound inhibits the DNA methyltransferase of human erythroleukemia cells (K562) in vitro. When the K562 cells were grown in medium containing methinin, fetal hemoglobin was produced. Small but detectable amounts of adult hemoglobin were also produced. Methinin was not toxic to these cells. The overall rate of genomic DNA methylation was reduced by 60% in cells grown in medium containing methinin. Southern blots of genomic DNA from methinin-treated cells and untreated cells hybridized to a 32P-labeled globin gene probe showed that one site in the globin gene region was hypomethylated. Methinin is a naturally occurring compound which inhibits DNA methylation both in vitro and in vivo.
从兔肝脏中分离出的一种天然存在的甲基化抑制剂，名为甲硫氨酸，可抑制多种甲基转移酶。甲硫氨酸是一种低分子量化合物（1400），含有一个活性胺基。该化合物在体外可抑制人红白血病细胞（K562）的DNA甲基转移酶。当K562细胞在含有甲硫氨酸的培养基中生长时，会产生胎儿血红蛋白。同时也会产生少量但可检测到的成人血红蛋白。甲硫氨酸对这些细胞无毒。在含有甲硫氨酸的培养基中生长的细胞中，基因组DNA甲基化的总体速率降低了60%。用32P标记的珠蛋白基因探针与经甲硫氨酸处理的细胞和未处理的细胞的基因组DNA进行Southern杂交，结果显示珠蛋白基因区域的一个位点发生了低甲基化。甲硫氨酸是一种天然存在的化合物，在体外和体内均可抑制DNA甲基化。
