Aida M, Yamane K, Nagata C
Mutat Res. 1986 Jan;173(1):49-54. doi: 10.1016/0165-7992(86)90010-2.
The molecular mechanism of induction of mutations by 2-aminopurine (AP) was studied by an ab initio molecular orbital method. Cytosine (C) is converted to its disfavored imino tautomer more easily than AP, judging from the calculated total energies of the bases and the base analogue. This suggests that a stable AP:C base mispair via two hydrogen bonds can be formed with the imino tautomer of C. These results stress the importance of the imino form of C in AP-induced mutagenesis and support the 'trigger mechanism', in which formation of one hydrogen bond between AP and C is considered to stimulate the tautomeric shift of AP or C. The calculated relative stabilities of various base pairs and mispairs were in good agreement with experimental findings.
采用从头算分子轨道方法研究了2-氨基嘌呤（AP）诱导突变的分子机制。从碱基和碱基类似物的计算总能量判断，胞嘧啶（C）比AP更容易转化为其不利的亚氨基互变异构体。这表明可以与C的亚氨基互变异构体形成通过两个氢键的稳定AP:C碱基错配。这些结果强调了C的亚氨基形式在AP诱导的诱变中的重要性，并支持“触发机制”，其中AP和C之间形成一个氢键被认为会刺激AP或C的互变异构转变。计算得到的各种碱基对和错配的相对稳定性与实验结果吻合良好。
