This volume provides up-to-date information on all major families of metal-binding proteins, including their structural, physico-chemical, and functional properties. After an introduction to cation binding, it discusses methods for the investigation of the binding of different cations to proteins. Then it gives characteristics of Ca-binding proteins, followed by descriptions of Mg, Zn, Fe, Co, Cu, Wo, Mn, Na, and K-binding proteins. The final chapter deals with the interaction of different cations with nucleic acids. With principles of proteomics and examples throughout, this is the definitive reference on metal-binding proteins.