Quantum chemical study on the interaction of some bisphosphonates and Ca2+: the role of molecular electrostatic potentials in the prediction of binding geometry.

Molecular electrostatic potentials have been used to model the calcium binding properties of some bisphosphonate drugs, which are used to treat various bone diseases. The mechanism of action involves the binding of bisphosphonates to the bone surface, where calcium plays an important role. Electrostatic potential maps derived from ab initio partial charges have been compared with both the crystal structure and the fully optimized ab initio structure of (dichloro)methylene-bisphosphonate-calcium ion complex. Molecular electrostatic potentials can correctly predict the calcium binding geometry of bisphosphonate-type compounds and this type of information can be used in the practical drug design work.