Understanding the Interaction Between DNA Quadruplex and Gemini Surfactants

The physical properties of the DNA quadruplex formed from (TTAGGG)4 in K+ solutions as well as the micelles formed from the Gemini surfactants with the composition RR’2N+(CH2)nN+RR’2 2Br, where R is -(CH2)11CH3, R’ is -CH3, and n=2, 3 or 4, have been studied. The interactions between the quadruplex and surfactant at different concentrations of surfactant was investigated through CD and UV/Vis techniques. Data showed that at concentrations greater than the cmc, all DNA precipitated out of the solution. At a concentration lower than cmc, some DNA precipitated out and the rest in the solution assumed the quadruplex conformation. Evident data showed that the formation of precipitate formed by the quadruplex and 12-4-12 surfactant is dependent on the concentration of the DNA, the concentration of surfactant, the ratio between the two, and the concentration of K+.