Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
580457 | Journal of Hazardous Materials | 2010 | 5 Pages |
Abstract
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 1.76Â ÃÂ 106Â LÂ molâ1 and 6.18Â ÃÂ 105Â LÂ molâ1 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.
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Authors
Zhenxing Chi, Rutao Liu, Yajing Sun, Meijie Wang, Pengjun Zhang, Canzhu Gao,