文摘
The significance of halogen bonding in protein鈥搇igand interactions has been recognized recently. We present here the first comprehensive thermodynamic and structural characterization of halogen bonding in PDE5鈥搃nhibitor interactions. ITC studies reveal that binding strength of the halogen bonding between chlorine, bromine, and iodine of inhibitor and the protein is 鈭?.57, 鈭?.09, and 鈭?.59 kJ/mol, respectively. The halogens interact with the designed residue Y612 and an unexpected buried water molecule.