N. Yoshida et al., ISOLATION AND CHARACTERIZATION OF A HEAVY METAL-BINDING PROTEIN FROM A HEAVY METAL-RESISTANT STRAIN OF THIOBACILLUS SP, Journal of fermentation and bioengineering, 76(1), 1993, pp. 25-28
A cadmium-inducible, high-molecular-weight, heavy metal-binding protei
n was isolated from cadmium-exposed cells of Thiobacillus sp. strain 1
3-1. The protein was purified by SDS-polyacrylamide gel electrophoresi
s, and extracted from the gel and renatured. The molecular weight of t
he protein was about 150 kDa and it bound 6.5, 5.2, and 1.5 gram atoms
of cadmium, copper, and zinc per mole of protein, respectively. The p
rotein contained abnormal levels of histidine residues and low levels
of cysteine residues. Together with the physicochemical characteristic
s of the protein, these results provide the first conclusive evidence
for the existence of a novel type of heavy metal-binding protein in mi
croorganisms.