Toulmé J J, Hélène C
J Biol Chem. 1977 Jan 10;252(1):244-9.
The binding of the tripeptide Lys-Trp-Lys to native, denatured, and ultraviolet-irradiated DNAs has been investigated by fluorescence spectroscopy. Two types of complexes are formed which both involve electrostatic interactions. Only one of them involves a stacking of the tryptophyl ring with nucleic acid bases. Quantitative analysis of fluorescence data shows that this stacking interaction is strongly favored in denatured as compared to native DNA. In ultraviolet-irradiated DNA, the peptide Lys-Trp-Lys binds selectively to unpaired regions around thymine dimers. Due to the stacking interaction of the aromatic amino acid with nucleic acid bases, this simple tripeptide is therefore able to discriminate between single-stranded and double-stranded regions in a nucleic acid.
通过荧光光谱法研究了三肽Lys-Trp-Lys与天然、变性和紫外线照射的DNA的结合情况。形成了两种类型的复合物，二者均涉及静电相互作用。其中只有一种涉及色氨酸环与核酸碱基的堆积。荧光数据的定量分析表明，与天然DNA相比，这种堆积相互作用在变性DNA中更受青睐。在紫外线照射的DNA中，肽Lys-Trp-Lys选择性地结合到胸腺嘧啶二聚体周围的未配对区域。由于芳香族氨基酸与核酸碱基的堆积相互作用，因此这种简单的三肽能够区分核酸中的单链和双链区域。
