The action of organic mercurials on the erythrocyte membrane

The solubilisation of proteins from erythrocyte membranes by treatment with organic mercurials has been studied with different species. The marked solubilisation previously reported for human membranes does not seem to be a general phenomenon. All of the other species examined showed less than 50% of the solubilisation shown by human membranes. The protein-solubilising effect seems to be dependent on hydrophobic mercury derivatives carrying a net negative charge. Uncharged compounds like phenylmercuric acetate blocked the effect, although N-ethylmaleimide and iodoacetamide did not. With the aid of radioactively labelled compounds, and of atomic absorption spectrophotometry, the proteins reactive towards the mercurials were identified. The major integral protein, band 3, was the major protein capable of binding the mercurial. Reaction with the mercurial appears to disrupt interaction of band 3 with bands 2.1 and 4.2, allowing dissociation of the cytoskeleton from the membrane. In addition, band 4.9 was also found to react with the mercurials, possibly resulting in disruption of the cytoskeleton.