Nishio H, Ono A, Matsuda A, Ueda T
Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
Nucleic Acids Res. 1992 Feb 25;20(4):777-82. doi: 10.1093/nar/20.4.777.
Oligodeoxyribonucleotides containing N6-methoxyadenine (M) have been synthesized. The order of stability of duplexes consisting of synthesized oligodeoxyribonucleotides, 5'd(CCTGGTAXCAGGTCC)3'-5'd(GGACCTGNTACCAGG)3' (X = M, A, G. N = A, G, T, C), was M: A (Tm = 52 degrees C) greater than M: T (50 degrees C) greater than M: G (48 degrees C) greater than M: C (46 degrees C) observed by thermal denaturation in a buffer of 0.01 M Na cacodylate, and 0.1 M NaCl at pH 7.0. The Tms are within a range of 6 degrees of difference, which is smaller than those of Tms of the duplexes containing A:N pairs (11 degrees) and G:N pairs (11 degrees). DNA replication study on a template-primer system, 5'd(32p-CAGCTTTCGC)3' 3'd(GTCGAAAGCGMAGTCG)5', showed that TTP and dCTP were incorporated into DNA strands at a site opposite to M by Klenow DNA polymerase, but dATP and dGTP were not.
已合成了含有N6-甲氧基腺嘌呤（M）的寡脱氧核糖核苷酸。由合成的寡脱氧核糖核苷酸5'd（CCTGGTAXCAGGTCC）3'-5'd（GGACCTGNTACCAGG）3'（X = M、A、G；N = A、G、T、C）组成的双链体的稳定性顺序为：在0.01 M 二甲胂酸钠和0.1 M NaCl、pH 7.0的缓冲液中通过热变性观察到，M:A（熔解温度Tm = 52℃）大于M:T（50℃）大于M:G（48℃）大于M:C（46℃）。这些熔解温度的差异在6℃范围内，小于含有A:N对（11℃）和G:N对（11℃）的双链体的熔解温度差异。对模板-引物系统5'd（32P-CAGCTTTCGC）3' 3'd（GTCGAAAGCGMAGTCG）5'进行的DNA复制研究表明，TTP和dCTP可被Klenow DNA聚合酶掺入与M相对的位点的DNA链中，但dATP和dGTP则不能。
