OCCURRENCE OF METALLOTHIONEIN-LIKE METAL-BINDING PROTEINS IN THE MARINE BIVALVE MACOMA-BALTHICA

The occurrence of metallothianein-like metal binding proteins in the heat-stable cytosol of the whole soft tissues of the clam Macoma balthica from a European population is shown. In vitro intoxication by Cd, Cu and Zn strongly affects the orginal metal intracellular partitioning between the insoluble phase, the high molecular weight proteins and the heat-stable cytosol. It is to be noted in particular the increase in the cytosol of the concentrations of metals and of metal binding proteins displaying several of the main characteristics of metallothioneins isolated from other marine invertebrates.