Fig. (2). Hydrophobic Exposures upon Metal Binding ANS binding to CaBD was monitored in the presence of 500 µM EDTA (dotted line), 2 mM Mg²⁺ plus 1 mM EGTA (dash line), and 100 µM Ca²⁺ (solid line). ANS binding to E99Q/E143Q in the presence of 100 µM Ca²⁺ is presented as a dash-dotted line.