Λ-、Δ-[Rh(bpy)_2chrysi]^(3+)对含C:T错配的DNA序列识别作用的分子模拟研究

Molecular modeling on recognition of DNA sequence including C : T Mismatch base pair by Λ-、Δ-[Rh(bpy)_2chrysi]^(3+)

通过分子模拟方法研究了手性金属配合物[Rh(bpy)2Chrysi]3+(bpy=2,2’- bipyridine;Chrysi=5,6-chrysenequinonediimine)对包含C:T错配碱基对的B-DNA序列的识别作用。结合类似的针对含G:A错配的和正常的B-DNA序列的识别作用研究,发现配合物[Rh(bpy)2Chrysi]3+可以对错配B-DNA序列进行序列特异性的识别．能量对比计算结果表明,该经典插入识别作用倾向于在错配碱基对附近进行,其中Δ-[Rh(bpy)2charysi]3+比其手性异构体更占优势．这同Barton教授工作组的实验结果是一致的。另外插入作用倾向于在错配序列中的正常双碱基对C3A4／G374(错配碱基对附近)中从小沟进行．与该配合物对含G:A错配的和正常的B-DNA序列的识别作用不同的是,对包含C:T错配碱基对的B-DNA序列的识别作用倾向于从小沟进行．这一点可能源于C:T碱基对结构的不同．

Recognition of B-DNA sequence including C-T mismatch base pair by metal complex [Rh （bpy）2Chrysi]^3＋ （bpy=2,2-bipyridine; Chrysi=5,6-chrysenequinonediimine） is studied by molecular modeling. Comparision between the calculating results and previous similar study on sheared （contain G：A mismatch base pairs ）and normal sequence indicated that, the complex [Rh（bpy）2 Chrysi]^3＋ can surely recognize mismatch DNA with sequence specificity. Same to the experimental resullts of Barton workgroups, the recognition of [Rh（bpy）2Chrysi]^3＋ for the DNA sequence d[GCCAC CAGCTC - CGGTGTTCGAG] shows of sequence,groove and enantio- specificity in theoretical calculation. It is found that, the intercalation at normal duplex C3A4/G3T4 from minor groove is of preferential. Even the site-specificity is similar to that of experimental results （near mismatch base pair）, the groove specificity of the modeling is on the contrary of the experiment methods.