title: Interactions in solution of cobalt(II) and nickel(II) with nicotinamide adenine dinucleotide: a potentiometric and calorimetric study.
abstract: The equilibrium constants and the thermodynamic parameters enthalpy and entropy of the interaction between Ni(II) and Co(II) with NAD(+) in aqueous solution were determined by calorimetry and potentiometry methods (ionic strength adjusted to 0.1 with sodium nitrate at 25 degrees C). The macrochelation of the systems was also studied. All the data, including the protonation enthalpy data of NAD(+) (very similar to the protonation enthalpy of 5'-AMP) suggest a less restrictive model for the NAD(+) "folded" conformation without intramolecular stacking between the bases, in agreement both with recent theoretical calculations and with the X-ray structure of trimethylene-bisadeninium or the free acid form of NAD(+).
authors.affiliation: Departament de Química, Facultat de Ciències, Universitat de les Illes Balears, 07071 Palma de Mallorca, Spain.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Herrero
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Cerro-Garrido
authors.forename: María Cristina
authors.initials: MC
authors.lastname: Apella
authors.forename: Angel
authors.initials: A
authors.lastname: Terrón-Homar
mesh_terms: D002151:Calorimetry; D002413:Cations, Divalent / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry*; D008968:Molecular Conformation; D009243:NAD / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D011199:Potentiometry; D012996:Solutions; D013816:Thermodynamics
chemical_list: D002413:Cations, Divalent; D012996:Solutions; D009243:NAD; D003035:Cobalt; D009532:Nickel