Abstract
A Cd-binding protein was isolated from roots of the grass A. gigantea Roth. Heat-stable proteins were chromatographed on the anion exchanger QAE-Sephadex A-25. The major Cd fraction was purified further by gel filtration on Sephadex G-75 in 1 M KCl buffer. The resulting protein preparation was light brown, had an apparent MW of 3700, contained 29% cysteine and close to 4 gram atoms Cd/mole. The Cd:cysteine ratio was 1:2.7. Spectroscopic measurements indicated Cd-thiolate coordination. The roots produced the metallothionein-like protein when they were exposed to Cd for 7 days.