A cadmium-binding protein rich in cysteine and acidic amino acid residues was isolated from roots of Agrostis gigantea. The molar ratio of cysteine to cadmium was 2.7:1. Electronic absorption and circular dichroism measurements were characteristic of cadmium-thiolate coordination. The cadmium-binding centre in the plant protein was strikingly similar to that of the well characterised vertebrate cadmiumthioneins.
