Faculty of Chemistry, Sensor and Biosensor Research Center and Nanoscience and Nanotechnology Research Center, Razi University, Kermanshah, Islamic Republic of Iran.
DNA Cell Biol. 2011 Jul;30(7):499-505. doi: 10.1089/dna.2010.1181. Epub 2011 Apr 10.
The interaction of native calf thymus DNA with tartrazine in 10 mM Tris-HCl aqueous solution at neutral pH 7.4 was investigated. Tartrazine is a nitrous derivative and may cause allergic reactions, with a potential of toxicological risk. Also, tartrazine induces oxidative stress and DNA damage. Its DNA binding properties were studied by UV-vis and circular dichroism spectra, competitive binding with Hoechst 33258, and viscosity measurements. Tartrazine molecules bind to DNA via groove mode as illustrated by hyperchromism in the UV absorption band of tartrazine, decrease in Hoechst-DNA solution fluorescence, unchanged viscosity of DNA, and conformational changes such as conversion from B-like to C-like in the circular dichroism spectra of DNA. The binding constants (K(b)) of DNA with tartrazine were calculated at different temperatures. Enthalpy and entropy changes were calculated to be +37 and +213 kJ mol(-1), respectively, according to the Van't Hoff equation, which indicated that the reaction is predominantly entropically driven. Also, tartrazine does not cleave plasmid DNA. Tartrazine interacts with calf thymus DNA via a groove interaction mode with an intrinsic binding constant of 3.75 × 10(4) M(-1).
在中性 pH 值 7.4 的 10 mM Tris-HCl 水溶液中，研究了天然小牛胸腺 DNA 与食用柠檬黄的相互作用。食用柠檬黄是一种亚硝衍生物，可能会引起过敏反应，具有潜在的毒理学风险。此外，食用柠檬黄会诱导氧化应激和 DNA 损伤。通过紫外-可见光谱和圆二色性光谱、与 Hoechst 33258 的竞争结合以及粘度测量研究了其与 DNA 的结合特性。食用柠檬黄分子通过沟槽模式与 DNA 结合，如食用柠檬黄的紫外吸收带的增色、Hoechst-DNA 溶液荧光的降低、DNA 粘度不变以及 DNA 圆二色性光谱中从 B 型到 C 型的构象变化所示。在不同温度下计算了 DNA 与食用柠檬黄的结合常数（K(b)）。根据范特霍夫方程，计算出焓变和熵变为 +37 和 +213 kJ mol(-1)，这表明反应主要是熵驱动的。此外，食用柠檬黄不会切割质粒 DNA。食用柠檬黄通过沟槽相互作用与小牛胸腺 DNA 相互作用，内在结合常数为 3.75×10(4) M(-1)。
