title: 1H and 13C NMR study of the complex formed by copper(II) with the nucleoside antibiotic sinefungin.
abstract: Sinefungin (SFG) is an antifungal and antiparasitic nucleoside antibiotic composed by ornithine and adenosine moieties both having the potential to bind copper(II). NMR studies performed at physiological pH have shown that the alpha-amino and the carboxylate groups in the ornithine unit are the preferred donor sites for Cu(II) binding. On the contrary, at acidic pH, Cu(II) complexation starts from adenosine nitrogen being the alpha-amino group still protonated and not available for metal binding. The proton paramagnetic relaxation enhancements measured at neutral pH allowed to obtain the 3D structure of the 1:2 Cu(II)-SFG complex. Molecular dynamics calculations were revealing for the existence of secondary Cu(II) interaction with the purine nitrogens of the adenosine moiety.
authors.affiliation: Department of Chemistry, University of Siena, Via Aldo Moro, 53100 Siena, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Cappannelli
authors.forename: Elena
authors.initials: E
authors.lastname: Gaggelli
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Jezowska-Bojczuk
authors.forename: Elena
authors.initials: E
authors.lastname: Molteni
authors.forename: Ariel
authors.initials: A
authors.lastname: Mucha
authors.forename: Elena
authors.initials: E
authors.lastname: Porciatti
authors.forename: Daniela
authors.initials: D
authors.lastname: Valensin
authors.forename: Gianni
authors.initials: G
authors.lastname: Valensin
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000737:chemistry; D000935:Antifungal Agents / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D000935:Antifungal Agents; D003300:Copper; D000241:Adenosine; C006235:sinefungin