Sub-cellular location of mercury in yeast grown in the presence of mercuric chloride.

The distribution of 203Hg in Saccharomyces cerevisiae grown in the presence of mercuric chloride has been examined by physical and chemical fractionation procedures and autoradiography. The major fraction of the bound mercury is tightly bound to the wall. A significant quantity of mercury penetrates to the cytoplasm but only a minor fraction is present as low molecular weight components. The wall associated mercury is not readily released by extraction with sodium hydroxide or ethylenediamine but a major fraction is solubilized by pronase and Helicase treatment. Isolated walls are capable of binding their own weight of mercury to high-affinity adsorption sites. The major role of the cell envelope in the in vivo binding of mercury and the penetration to the cytoplasm of mercury was confirmed by autoradiography.