A possible calcium binding site in animal lectins: a 1H-NMR study of the interaction between lanthanides and a synthetic peptide from a highly conserved domain of Pleurodeles lectin.

1H-NMR techniques have been used to study the metal binding properties of a synthetic peptide of 15 amino acids corresponding to a highly conserved domain of Pleurodeles lectin. The addition of lanthanum chloride or praseodymium chloride in a peptide solution induces some conformational changes as displayed by several concerted variations of peptide resonances. The Ln3+ concentration dependence of the chemical shifts was used to calculate the Ln3+ binding constants. The dissociation constants of 95 microM and 280 microM were found for La3+ and Pr3+, respectively.