School of Environmental Science and Engineering, Shandong University, 27 Shanda South Road, Jinan 250100, PR China.
J Hazard Mater. 2010 Mar 15;175(1-3):274-8. doi: 10.1016/j.jhazmat.2009.09.160. Epub 2009 Oct 7.
The gene toxic interactions of toluidine blue (TB) with calf thymus DNA (ct-DNA) were examined in vitro with UV-visible absorption spectroscopy, fluorescence spectroscopy, fluorescence polarization and circular dichroism techniques. The experimental results showed that TB interacted with ct-DNA by two binding modes. At low TB concentrations, TB intercalated into the DNA base pairs. At higher TB concentrations, TB was attached to the negatively charged phosphate groups. For the intercalation binding mode and electrostatic binding mode, the binding constants were 1.76 x1 0(6)L mol(-1) and 6.18 x 10(5)L mol(-1) and the number of binding sites was 0.48 and 0.79, respectively. Circular dichroism results showed that the two binding modes had different effects on the ct-DNA conformation. At high dye concentrations, Z-form DNA appears, while at low TB concentrations, a B to A form transition is observed.
采用紫外可见吸收光谱、荧光光谱、荧光偏振和圆二色性技术研究了甲苯胺蓝（TB）与小牛胸腺 DNA（ct-DNA）的基因毒性相互作用。实验结果表明，TB 通过两种结合模式与 ct-DNA 相互作用。在低 TB 浓度下，TB 嵌入 DNA 碱基对中。在较高的 TB 浓度下，TB 附着在带负电荷的磷酸基团上。对于插入结合模式和静电结合模式，结合常数分别为 1.76 x1 0(6)L mol(-1)和 6.18 x 10(5)L mol(-1)，结合位点数分别为 0.48 和 0.79。圆二色性结果表明，两种结合模式对 ct-DNA 构象有不同的影响。在高染料浓度下，出现 Z 型 DNA，而在低 TB 浓度下，观察到 B 到 A 型构象转变。
