Peptide Bond Modification for Metal Coordination: 3. Metal-Binding Properties of Phosphorus-Based Pseudo-peptides

Abstract

A symposium report. Novel linear and cyclic diphosphinic acid based pseudo-peptides were designed as models to evaluate the potential of phosphorus-contg. moieties as metal binding sites in the pseudopeptides. The diphosphinic based pseudo-peptides exhibited high binding affinity and selectivity for Fe3+ and Fe2+ among the metal ions Cu2+, Zn2+, Fe3+, Co2+, Ni2+, Cd2+, Fe2+ and Mn2+, indicating that the phosphinic moiety could be a highly selective ligand for iron ion coordination. Competition binding assays suggest that an eight-atom length between two phosphinic groups in a linear ligand may provide enough conformational flexibility for iron coordination. A longer length between two phosphinic groups in a cyclic ligand is essential to maintain high metal binding affinity. [on SciFinder (R)]