Evidence of presence of a low molecular weight, non-metallothionein-like metal-binding protein in the marine gastropod Nassarius reticulatus L.

Abstract

1. 1. A low molecular weight metal-binding protein was found in the snail Nassarius reticulatus cytosol, which was induced in heavy metal contaminated environments. 2. 2. In our sodium dodecyl sulfate-mercaptoethanol polyacrylamide gel systems it behaved as a protein of 19 kDa mol. wt. 3. 3. Amino acid composition studies definitely established this protein not to be metallothionein (Mt) like, because it had a much lower level of cysteine and substantial amounts of aromatic amino acids and histidine. 4. 4. The metal-binding strength of this protein was concluded to be much weaker than that of Mt. 5. 5. In the crustacean Pagurus bernhardus L. such a protein could not be demonstrated. 6. 6. In both the snail and the crustacean Zn may inhibit the accumulation of Hg. The premise for studying the induction of the metal-binding Nassarius protein as a supplement to environmental metal monitoring purposes is briefly discussed.