Pakravan Parvaneh, Masoudian Shahla
Department of Chemistry, Zanjan Branch, Islamic Azad University, Zanjan, Iran.
Department of Chemistry, Payame Noor University, I.R. of Iran.
Iran J Pharm Res. 2015 Winter;14(1):111-23.
The interaction between isatin-β-thiosemicarbazone (IBT) and calf thymus DNA (CT-DNA) was investigated in physiological buffer (pH 7.4) using Neutral Red (NR) dye as a spectral probe by UV-Vis absorption and fluorescence spectroscopy, as well as viscosity measurements. The IBT is stabilized by intercalation in the DNA (K [IBT -DNA] = 1.03×10(5) M(-1)), and displaces the NR dye from the NR-DNA complex. The binding constants Kf and number of binding sites (n≈1) of IBT with DNA were obtained by fluorescence quenching method at different temperatures. Furthermore, the enthalpy and entropy of the reaction between IBT and CT-DNA showed that the reaction is enthalpy-favored and entropy-disfavored. The changes in the base stacking of CT-DNA upon the binding of IBT are reflected in the circular dichroic (CD) spectral studies. The viscosity increase of CT-DNA solution is another evidence to indicate that, IBT is able to be intercalated in the DNA base pairs.
在生理缓冲液（pH 7.4）中，以中性红（NR）染料作为光谱探针，通过紫外 - 可见吸收光谱、荧光光谱以及粘度测量，研究了异吲哚酮 -β- 硫代半卡巴腙（IBT）与小牛胸腺DNA（CT - DNA）之间的相互作用。IBT通过插入DNA中而稳定存在（K[IBT - DNA] = 1.03×10⁵ M⁻¹），并从NR - DNA复合物中取代NR染料。通过荧光猝灭法在不同温度下获得了IBT与DNA的结合常数Kf和结合位点数量（n≈1）。此外，IBT与CT - DNA反应的焓和熵表明该反应是焓有利而熵不利的。圆二色（CD）光谱研究反映了IBT结合后CT - DNA碱基堆积的变化。CT - DNA溶液粘度的增加是另一个证据，表明IBT能够插入DNA碱基对中。
Zotero 插件