Nielsen P E, Egholm M, Buchardt O
Department of Biochemistry B, Panum Institute, Copenhagen, Denmark.
J Mol Recognit. 1994 Sep;7(3):165-70. doi: 10.1002/jmr.300070303.
The binding of PNA (peptide nucleic acid) T2CT2CT4-LysNH2 to the double-stranded DNA target 5'-A2GA2GA4 was studied by KMnO4 and dimethylsulfate (DMS) probing. It is found that upon sequence-specific strand displacement binding of the PNA to the dsDNA target concomitant protection of the N-7 of guanines within the target takes place. It is furthermore shown that the binding of this PNA is more efficient at pH 5.5 than at pH 6.5 and very inefficient at pH 7.5. These results clearly indicate that C+G Hoogsteen base pairing is present and important for binding and that the strand displacement complex therefore involves a PNA.DNA-PNA triplex.
通过高锰酸钾和硫酸二甲酯（DMS）探测研究了肽核酸（PNA）T2CT2CT4-LysNH2与双链DNA靶标5'-A2GA2GA4的结合。结果发现，PNA与dsDNA靶标发生序列特异性链置换结合时，会伴随对靶标内鸟嘌呤N-7的保护。此外还表明，该PNA在pH 5.5时的结合效率高于pH 6.5时，而在pH 7.5时效率极低。这些结果清楚地表明存在C+G Hoogsteen碱基配对且对结合很重要，因此链置换复合物涉及一个PNA·DNA-PNA三链体。
