Binding of 12-s-12 dimeric surfactants to calf thymus DNA: Evaluation of the spacer length influence.
Several cationic dimeric surfactants have shown high affinity towards DNA. Bis-quaternary ammonium salts (m-s-m) have been the most common type of dimeric surfactants investigated and it is generally admitted that those that posses a short spacer (s≤3) show better efficiency to bind or compact DNA. However, experimental results in this work show that 12-s-12 surfactants with long spacers make the surfactant/ctDNA complexation more favorable than those with short spacers. A larger contribution of the hydrophobic interactions, which control the binding Gibbs energy, as well as a higher average charge of the surfactant molecules bound to the nucleic acid, which favors the electrostatic attractions, could explain the experimental observations. Dimeric surfactants with intermediate spacer length seem to be the less efficient for DNA binding.
Department of Physical Chemistry, University of Seville, C/Profesor García González 1, 41012 Seville, Spain.
Beatriz
B
Sarrión
Department of Physical Chemistry, University of Seville, C/Profesor García González 1, 41012 Seville, Spain.
Eva
E
Bernal
Department of Physical Chemistry, University of Seville, C/Profesor García González 1, 41012 Seville, Spain.
Victoria Isabel
VI
Martín
Department of Chemical Engineering, Physical Chemistry and Materials Science, Faculty of Experimental Sciences, Campus de El Carmen, Avda. de las Fuerzas Armadas s/n, 21071 Huelva, Spain.
Manuel
M
López-López
Department of Physical Chemistry, University of Seville, C/Profesor García González 1, 41012 Seville, Spain.
Pilar
P
López-Cornejo
Department of Vegetal Biochemistry and Molecular Biology, University of Seville, C/Profesor García González 1, 41012 Seville, Spain.
Margarita
M
García-Calderón
Department of Physical Chemistry, University of Seville, C/Profesor García González 1, 41012 Seville, Spain. Electronic address: moya@us.es.
María Luisa
ML
Moyá
D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism*; D019281:Dimerization; D018625:Microscopy, Atomic Force; D055672:Static Electricity; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D014466:Ultraviolet Rays
D013501:Surface-Active Agents; D004247:DNA; C427203:calf thymus DNA
Calf thymus DNA; Charge inversion; DNA compaction; Dimeric surfactants; Electromotive force; Spacer length