DFT Comparison of Fe 2+ Hydration in the Binding Sites of the Ferroxidase Center of Bullfrog M Ferritin

• Autores: Bacelo, Daniel Enrique; Binning, R. C.
• Año de publicación: 2009
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Ferroxidase Center; Ferritin; Density Functional Theory
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Density functional theory optimizations have been conducted on structures of complexes of Fe2+ with (H2O)n (n ) 0-3) in three-residue models of binding sites A and B of the ferroxidase center of bullfrog M ferritin. Each site is modeled by the full structures of its three active amino acids. The potential surface at each site in the presence of water molecules is complex; coordination numbers of iron from three to six are seen. Water contributes to the complexity through its ability to hydrogen bond, to coordinate to iron, and to displace the neutral ligands glutamine and histidine. Intrinsic differences are noted at each site; at site B, the most stable complexes are found to favor tetracoordinate iron, while pentacoordination is preferred at site A in the two- and three-water complexes. While each incremental addition of a water molecule results in increased stability, successive binding energies are found to decrease.2+ with (H2O)n (n ) 0-3) in three-residue models of binding sites A and B of the ferroxidase center of bullfrog M ferritin. Each site is modeled by the full structures of its three active amino acids. The potential surface at each site in the presence of water molecules is complex; coordination numbers of iron from three to six are seen. Water contributes to the complexity through its ability to hydrogen bond, to coordinate to iron, and to displace the neutral ligands glutamine and histidine. Intrinsic differences are noted at each site; at site B, the most stable complexes are found to favor tetracoordinate iron, while pentacoordination is preferred at site A in the two- and three-water complexes. While each incremental addition of a water molecule results in increased stability, successive binding energies are found to decrease.
Fil: Bacelo, Daniel Enrique. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Comodoro. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Binning, R. C.. Universidad Metropolitana; Venezuela