Cooperative interaction between metallosurfactants, derived from the [Ru(2,2'-bpy)3](2+) complex, and DNA.
With the idea of improving and advancing the design and preparation of new reagents based on cationic surfactants for gene therapy, two luminescent metallosurfactants derived from the [Ru(2,2'-bpy)3](2+) complex were synthesized. Their interaction with DNA and the effect they exert on the conformation of the polynucleotide were studied by using different techniques. The equilibrium binding constants, Kb, of the two surfactants to DNA were obtained at different molar ratios X=[surfactant]/[DNA]. The observed sigmoidal dependence of Kb on X confirms the cooperative character of the binding. After the addition of a determined surfactant concentration, the condensation of the polymer was observed. The amount of surfactant needed to produce this conformational change is lower for the double stranded surfactant than for the single chain surfactant due to a stronger hydrophobic interaction. The addition of α-cyclodextrin molecules to the metallosurfactant/DNA solutions results in polynucleotide decompaction, which confirms the importance of the hydrophobic interactions in the condensation of the polynucleotide. Results also show the importance of choosing both a proper system to study and the most seeming measuring technique to use. It is demonstrated that, in some cases, the use of several techniques is desirable to obtain reliable and accurate results.
Departamento de Química Física, Universidad de Sevilla, c/ Prof. García González 1, 41012 Sevilla, Spain.
J A
JA
Lebrón
Departamento de Química Física, Universidad de Sevilla, c/ Prof. García González 1, 41012 Sevilla, Spain.
F J
FJ
Ostos
Departamento de Química Física, Universidad de Sevilla, c/ Prof. García González 1, 41012 Sevilla, Spain.
M L
ML
Moyá
Departamento de Ingeniería Química, Química Física y Química Orgánica, Universidad de Huelva, Campus 'El Carmen', Facultad de Ciencias Experimentales, E-21071, Spain.
M
M
López-López
Departamento de Química Inorgánica, Facultad de Química, Universidad de Sevilla, Aptdo. 1203, ES 41071 Sevilla, Spain.
C J
CJ
Carrasco
Departamento de Química Física, Universidad de Sevilla, c/ Prof. García González 1, 41012 Sevilla, Spain. Electronic address: pcornejo@us.es.
P
P
López-Cornejo
D004247:DNA / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D012413:Rubidium / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013501:Surface-Active Agents / Q000737:chemistry*
D008670:Metals; D013501:Surface-Active Agents; D004247:DNA; D012413:Rubidium
Condensation of DNA; Cooperative mode; Cyclodextrin; DNA; Metallosurfactant