Metallothionein induced in the frogXenopus laevis

Summary A low molecular weight cadmium- and copper-binding protein, induced in the liver of the frog,Xenopus laevis, by the administration of cadmium, was shown to consist of a single isoprotein and was characterized as an amphibian metallothionein based on its high cysteine and metal content, its low molecular weight, and the lack of aromatic amino acids.The authors thank Dr K. Kubota for his encouragement.