title: Multi-technique characterization of poly-L-lysine dendrigrafts-Cu(II) complexes for biocatalysis.
abstract: Poly-L-lysine is a biocompatible polymer used for drug or gene delivery, for transport through cellular membranes, and as nanosized magnetic resonance imaging contrast agents. Cu(II)-poly-L-lysine complexes are of particular interest for their role in biocatalysis. In this study, poly-L-lysine dendrigrafts (DGLs) at different generations (G2, G3, and G4) are synthesized and characterized in absence and presence of Cu(II) by means of electron paramagnetic resonance (EPR), UV-Vis, potentiometric titration and circular dichroism (CD). The analysis is performed as a function of the [Cu(II)]/[Lys] (=R) molar ratio, pH and generation by identifying differently flexible complexes in different dendrimer regions. The amine sites in the lateral chains become increasingly involved with the increase of pH. The good agreement and complementarity of the results from the different techniques provide an integrate view of the structural and dynamic properties of Cu(II)-DGL complexes implementing their use as biocatalysts.
authors.affiliation: Institut des Biomolecules Max Mousseron/UMR 5247 Université Montpellier II, Place Eugène Bataillon, 34095, Montpellier, France. jean-christophe.rossi@univ-montp2.fr.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Rossi
authors.forename: Barbara
authors.initials: B
authors.lastname: Maret
authors.forename: Kevin
authors.initials: K
authors.lastname: Vidot
authors.forename: Jean-Patrick
authors.initials: JP
authors.lastname: Francoia
authors.forename: Michela
authors.initials: M
authors.lastname: Cangiotti
authors.forename: Susanna
authors.initials: S
authors.lastname: Lucchi
authors.forename: Concetta
authors.initials: C
authors.lastname: Coppola
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Ottaviani
mesh_terms: D055162:Biocatalysis; D001672:Biocompatible Materials / Q000737:chemistry*; D002942:Circular Dichroism; D003198:Computer Simulation; D003300:Copper / Q000737:chemistry*; D050091:Dendrimers / Q000138:chemical synthesis* / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000737:chemistry*; D011107:Polylysine / Q000737:chemistry*; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D050091:Dendrimers; D009942:Organometallic Compounds; D011107:Polylysine; D003300:Copper
keywords: EPR spectroscopy; UV-Vis spectroscopy; circular dichroism; poly-L-lysine dendrigrafts; potentiometric titrations