Determining thermodynamic parameters from isothermal calorimetric isotherms of the binding of macromolecules to metal cations originally chelated by a weak ligand.
An accurate data analysis method for determining stoichiometry and thermodynamic parameters from isothermal titration calorimetry data for the binding of macromolecules to metal cations that are solubilized through an association with a weak ligand is presented. This approach is applied to determine the binding constant for the association of Cu(II) to the first 16 residues of the Alzheimer's amyloid beta peptide, Abeta(1-16) under conditions where Cu(II) is rendered soluble through weak binding to glycine. At pH 7.2 and 37 degrees C, a binding constant of 1.5 x 10(9) M-1 (Kd = 0.7 nM) is determined for the association of Cu(II) with Abeta(1-16).
Hong
Lian
L
Department of Chemistry, Duke University, Durham, North Carolina 27708, USA.
Bush
William D
WD
Hatcher
Lanying Q
LQ
Simon
John
J