title: NMR study of the interaction of fluorescent 3-hydroxy-4-pyridinone chelators with DMPC liposomes.
abstract: In the present study we discuss the interaction of two fluorescent 3-hydroxy-4-pyridinone chelators (MRB7 and MRB8) of different lipophilicities with DMPC liposomes based on the analysis of the shifts of the resonance NMR signals and changes in the translational diffusion of both species. The analysis of the variation of the resonance signals of the chelators indicates that both MRB7 and MRB8 strongly interact with the liposomes and that such interaction occurs through both the fluorophore and the chelating moieties of the chelator's framework. Analysis of the variations in the characteristic resonance signals of the lipid provides evidence that MRB7 is able to reach the hydrophobic zone of the bilayer independent of the chelator concentration. The present results corroborate the fact that ethyl substituents in the amino groups of the xanthene ring and the thiourea link are important for the chelator's ability to diffuse across the lipid bilayer.
authors.affiliation: REQUIMTE-UCIBIO, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal. galya.ivanova@fc.up.pt.
authors.forename: Tânia
authors.initials: T
authors.lastname: Moniz
authors.affiliation: REQUIMTE-LAVQ, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal.
authors.forename: Baltazar
authors.initials: B
authors.lastname: de Castro
authors.affiliation: REQUIMTE-UCIBIO, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal. mcrangel@fc.up.pt.
authors.forename: Maria
authors.initials: M
authors.lastname: Rangel
authors.affiliation: REQUIMTE-UCIBIO, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal. galya.ivanova@fc.up.pt.
authors.forename: Galya
authors.initials: G
authors.lastname: Ivanova
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D005453:Fluorescence; D008081:Liposomes; D066244:Proton Magnetic Resonance Spectroscopy; D011728:Pyridones / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D008081:Liposomes; D011728:Pyridones; C020366:3-hydroxy-4-pyridone; D004134:Dimyristoylphosphatidylcholine