Toulmé J J, Charlier M, Héléne C
Proc Natl Acad Sci U S A. 1974 Aug;71(8):3185-8. doi: 10.1073/pnas.71.8.3185.
Fluorescence studies of the binding of peptides containing lysyl and tryptophyl residues to nucleic acids show that two types of complexes are formed. One of them involves a direct interaction of the tryptophyl ring with nucleic acid bases, which leads to fluorescence quenching. Comparison with proton magnetic resonance and circular dichroism data indicates that this fluorescence quenching is due to a stacking of the indole ring with bases. Quantitative analysis of fluorescence data leads to the conclusion that stacking is favored in single-stranded regions of DNAs, which are produced either by heating or by UV-irradiation of the native DNA sample. The binding of the peptide Lys-Trp-Lys is about ten times tighter in these single-stranded regions as compared with double-stranded ones. A short tripeptide such as Lys-Trp-Lys is, therefore, able to discriminate between single-stranded and double-stranded regions. Moreover, bound peptide molecules photosensitize the splitting of thymine dimers in UV-irradiated DNA, thus providing a model for DNA photoreactivation.
对含有赖氨酰和色氨酰残基的肽与核酸结合的荧光研究表明，会形成两种类型的复合物。其中一种涉及色氨酰环与核酸碱基的直接相互作用，这会导致荧光猝灭。与质子磁共振和圆二色性数据的比较表明，这种荧光猝灭是由于吲哚环与碱基的堆积。对荧光数据的定量分析得出结论，在通过加热或对天然DNA样品进行紫外线照射产生的DNA单链区域中，堆积更受青睐。与双链区域相比，肽Lys-Trp-Lys在这些单链区域的结合紧密程度约高十倍。因此，像Lys-Trp-Lys这样的短三肽能够区分单链和双链区域。此外，结合的肽分子能使紫外线照射的DNA中的胸腺嘧啶二聚体发生光裂解，从而为DNA光复活提供了一个模型。
