Topal M D
Biochemistry. 1984 May 22;23(11):2367-72. doi: 10.1021/bi00306a007.
9-Aminoacridine was found to inhibit dNTP incorporation into DNA homopolymer duplexes by phage T4 DNA polymerase in vitro. Systematic variation of the molar ratio of 9-aminoacridine to DNA, to DNA polymerase, and to DNA precursors demonstrated that this inhibition at 9-aminoacridine concentrations below 10 microM was mainly due to interaction of 9-aminoacridine with the DNA and suggested that the basis for the preferential inhibition of incorrect precursor incorporation was destabilization of the DNA growing point. Consistent with destabilization, 9-aminoacridine stimulated the hydrolysis of correctly base paired DNA by the 3'-5' exonuclease activity of phage T4 DNA polymerase. This is the first indication to my knowledge that an intercalating dye destabilizes the DNA growing point, whereas it raises the overall Tm of the DNA. At 9-aminoacridine concentrations above 10 microM overall incorporation of dNTPs was inhibited by 9-aminoacridine interaction with the DNA polymerase. A possible explanation for the induction of both deletion and addition frameshift mutations by 9-aminoacridine during DNA biosynthesis is discussed in light of growing-point destabilization.
研究发现，9-氨基吖啶在体外可抑制噬菌体T4 DNA聚合酶将脱氧核苷三磷酸（dNTP）掺入DNA同聚物双链体中。对9-氨基吖啶与DNA、DNA聚合酶以及DNA前体的摩尔比进行系统变化研究表明，在9-氨基吖啶浓度低于10微摩尔时，这种抑制作用主要是由于9-氨基吖啶与DNA相互作用所致，这表明优先抑制错误前体掺入的基础是DNA生长点的不稳定。与不稳定作用一致，9-氨基吖啶通过噬菌体T4 DNA聚合酶的3'-5'核酸外切酶活性刺激正确碱基配对的DNA水解。据我所知，这是首次表明一种嵌入染料会使DNA生长点不稳定，而它却会提高DNA的整体解链温度（Tm）。在9-氨基吖啶浓度高于10微摩尔时，dNTP的整体掺入受到9-氨基吖啶与DNA聚合酶相互作用的抑制。鉴于生长点不稳定，讨论了9-氨基吖啶在DNA生物合成过程中诱导缺失和插入移码突变的可能解释。
