Reversibility of the interactions between a novel surfactant derived from lysine and biomolecules.
In this work the novel cationic surfactant derived from lysine (S)-5-acetamido-6-(dodecylamino)-N,N,N-trimethyl-6-oxohexan-1-ammonium chloride, LYCl, was prepared and the physicochemical characterization of its aqueous solutions was carried out. The binding of LYCl to bovine serum albumin, BSA, and to double stranded calf thymus DNA, ctDNA, was investigated using several techniques. Results show that LYCl binding to BSA is followed by a decrease in the α-helix content caused by the unfolding of the protein. LYCl association to ctDNA mainly occurs through groove binding and electrostatic interactions. These interactions cause morphological changes in the polynucleotide from an elongated coil structure to a more compact globular structure, resulting in the compaction of ctDNA. Addition of β-cyclodextrin, β-CD, to the BSA-LYCl and ctDNA-LYCl complexes is followed by the refolding of BSA and the decompaction of ctDNA. This can be explained by the ability of β-CD to hinder BSA-LYCl and ctDNA-LYCl interactions due to the stronger and more specific β-CD-LYCl hydrophobic interactions. The stoichiometry of the β-CD:LYCl inclusion complex and its formation equilibrium constant were determined in this work. The reported procedure using β-CD is an efficient way to refold proteins and to decompact DNA, after the morphological changes caused in the biomolecules by their interaction with cationic surfactants.
Department of Physical Chemistry, University of Seville, C/Profesor García González 1, 41012 Seville, Spain.
Victoria Isabel
VI
Martín
Department of Physical Chemistry, University of Seville, C/Profesor García González 1, 41012 Seville, Spain.
Beatriz
B
Sarrión
Department of Chemical Engineering, Physical Chemistry and Organic Chemistry, University of Huelva, Campo de El Carmen, 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 Organic Chemistry, University of Seville, C/Profesor García González 1, 41012 Seville, Spain.
Inmaculada
I
Robina
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; D002412:Cations / Q000737:chemistry; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry*; D008823:Micelles; D011489:Protein Denaturation; D017433:Protein Structure, Secondary; D058767:Protein Unfolding; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry
D002412:Cations; D008823:Micelles; D013501:Surface-Active Agents; D047392:beta-Cyclodextrins; D012710:Serum Albumin, Bovine; D004247:DNA; C427203:calf thymus DNA; D008239:Lysine
Bovine serum albumin; Calf thymus DNA; DNA Compaction; Protein denaturation; Surfactants; β-Cyclodextrin