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

The occurrence of metallothianein-like metal binding proteins in the h eat-stable cytosol of the whole soft tissues of the clam Macoma balthi ca from a European population is shown. In vitro intoxication by Cd, C u and Zn strongly affects the orginal metal intracellular partitioning between the insoluble phase, the high molecular weight proteins and t he heat-stable cytosol. It is to be noted in particular the increase i n the cytosol of the concentrations of metals and of metal binding pro teins displaying several of the main characteristics of metallothionei ns isolated from other marine invertebrates.