Synthesis and identification of artificial antigens for cadmium and copper

Cadmium and copper were conjugated to two carrier proteins using bifunctional chelators, including derivatives of ethylenediamine N,N,N′,N′-tetraacetic acid and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, to make artificial antigens for cadmium and copper. The artificial antigens were identified by nondenaturing gel electrophoresis, ultraviolet spectrophotometry, and graphite furnace atomic absorption spectrometry. Nondenaturing gel electrophoresis results revealed that the conjugate band migrations were different from those of the chelator-protein conjugates and carrier proteins alone. The ultraviolet spectrophotometry results revealed that the maximum absorption peak of the conjugates had only a little peak shift. The graphite furnace atomic absorption spectrometry results revealed that the metal content of the conjugates was much higher than that of the carrier proteins and chelator-protein conjugates. The results indicated that the artificial antigens for cadmium and copper were successfully synthesised and could be useful as immunising antigens.