title: Complexation of DNA with ruthenium organometallic compounds: the high complexation ratio limit.
abstract: Interactions between DNA and ruthenium organometallic compounds are studied by using visible light absorption and circular dichroism measurements. A titration technique allowing for the absolute determination of the advancement degree of the complexation, without any assumption about the number of complexation modes is developed. When DNA is in excess, complexation involves intercalation of one of the organometallic compound ligands between DNA base pairs. But, in the high complexation ratio limit, where organometallic compounds are in excess relative to the DNA base pairs, a new mode of interaction is observed, in which the organometallic compound interacts weakly with DNA. The weak interaction mode, moreover, develops when all the DNA intercalation sites are occupied. A regime is reached in which one DNA base pair is linked to more than one organometallic compound.
authors.affiliation: IPCMS/CNRS, Université de Strasbourg, UMR 7504 23 rue du Loess, 67034 Strasbourg, France. pascal.hebraud@ipcms.unistra.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Despax
authors.forename: Fuchao
authors.initials: F
authors.lastname: Jia
authors.forename: Michel
authors.initials: M
authors.lastname: Pfeffer
authors.forename: Pascal
authors.initials: P
authors.lastname: Hébraud
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009942:Organometallic Compounds; D012428:Ruthenium; D004247:DNA