title: Thermodynamics of Mn(2+)-binding to goat alpha-lactalbumin.
abstract: By means of reaction calorimetry we measured the apparent enthalpy change, delta Happ, of the binding of Mn(2+)-ions to goat alpha-lactalbumin as a function of temperature. The observed delta Happ can be written as the sum of contributions resulting from a conformational and a binding process. In combination with the thermal unfolding curve of goat alpha-lactalbumin, we succeeded in separating the complete set of thermodynamic parameters (delta H, delta G, delta S, delta Cp) into the binding and conformational contributions. By circular dichroism we showed that NH+4-ions, upon binding to bovine alpha-lactalbumin, induce the same conformational change as do Na+ and K+: the binding constant KappNH+4 equals 98 +/- 9 M-1.
authors.affiliation: Interdisciplinary Research Center, Katholieke Universiteit Leuven, Kortrijk, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Desmet
authors.forename: E
authors.initials: E
authors.lastname: Tieghem
authors.forename: H
authors.initials: H
authors.lastname: Van Dael
authors.forename: F
authors.initials: F
authors.lastname: Van Cauwelaert
mesh_terms: D000818:Animals; D002151:Calorimetry / Q000379:methods; D002942:Circular Dichroism; D005260:Female; D006041:Goats; D007768:Lactalbumin / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D008345:Manganese / Q000737:chemistry* / Q000378:metabolism; D008433:Mathematics; D008892:Milk; D011487:Protein Conformation; D013816:Thermodynamics
chemical_list: D008345:Manganese; D007768:Lactalbumin