Calorimetry Chagas disease Crystallography, X-Ray Drug Design Enzyme Inhibitors Geranyltranstransferase IC 50 Magnesium Models, Molecular Phosphonic Acids Protein Conformation Thermodynamics Trypanosoma cruzi X ray crystallography alkyl group allyl compound amine antitrypanosomal agent article binding affinity bisphosphonic acid derivative chemical bond complex formation conformation crystal structure drug design drug protein binding drug synthesis enthalpy entropy