Metal ion chelating peptides with superoxide dismutase activity

The superoxide dismutase activities of two novel synthetic chelating peptides are reported. The peptides comprise a polyaminocarboxylic acid chelator (EDTA) conjugated to tyrosine (ET1) and phenylalanine (EP1). Superoxide dismutase (SOD) activity was exhibited for Cu(II) but not the Fe(III) complexes. The mimetic activities were compared to bovine erythrocyte SOD (3730 U/mg) and exhibited activities of 1119 U/mg for ET1-Cu(II) and 551 U/mg for EP1-Cu(II). Thus, small alterations in structure can have significant effects on the enzymatic activity of metallopeptides. These synthetic chelators have dual potential anti-inflammatory activity by chelating deleterious non-protein bound metal ions and concomitantly affording anti-oxidant mimetic activity.