title: Copper(II) increases bile acid binding to asparagine.
abstract: Interactions of two bile acids (cholic and glycocholic acids) with asparagine have been studied by potentiometry in aqueous solutions under conditions similar to those observed in biological fluids (37 degrees C and I = 0.15 M NaCl), and in the absence and presence of copper(II). To characterize the equilibria for the systems copper(II)/bile acid/asparagine, specifically to assess cooperative binding between bile acids and asparagine, the acidity constant of asparagine and formation constants for copper(II)/bile acid and copper(II)/asparagine were also obtained under the same conditions. The results obtained suggest cooperativity in the binding of bile acid to asparagine in the presence of copper(II).
authors.affiliation: CEQUP/Departamento de Química, Faculdade de Ciências, Universidade do Porto, Portugal.
authors.forename: B
authors.initials: B
authors.lastname: de Castro
authors.forename: J L
authors.initials: JL
authors.lastname: Lima
authors.forename: I H
authors.initials: IH
authors.lastname: Mayer
authors.forename: S
authors.initials: S
authors.lastname: Reis
mesh_terms: D001216:Asparagine / Q000737:chemistry*; D001647:Bile Acids and Salts / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration
chemical_list: D001647:Bile Acids and Salts; D001216:Asparagine; D003300:Copper