Initial Structural Studies of Charged Receptors That Bind to Inorganic Phosphate Anion and to an Anionic Phospholipid Found in Bacterial Membranes

ITC titration studies of a family of bis-ammonium receptors based upon a scaffold of two bis-linked phenol rings show that several of the receptors bind to both dihydrogenphosphate and phosphatidylglycerol anions in a similar binding motif. Thermodynamic properties determined from ITC show that anion binding is entropy driven. Job plots determined from 1H NMR clearly demonstrate that anion−receptor binding stoichiometry is dependent on the receptor’s length of its bis-amine linkage.