Rapid screening of peptides for heavy metal binding

A simple method that allows testing and characterisation of cadmium binding motifs by large set of immobilized peptides was developed. Hepta- and octapeptides containing cysteine and histidine residues were synthesized on cotton carrier. They were tested for cadmium binding. pH values of half metal dissociation were measured. Test for Cd binding was based on its precipitation with ferrous dipyridyl iodide. Subsequent dissolving of precipitate provided semiquantitative data on relative amount of Cd bound. Observed data for particular peptides corresponded with prediction.