[Study of the chemical receptor for diphtheria toxin in cell membranes].

Adsorption of diphtheria toxin on immobilized cell membrane preparations in the presence of gangliosides was studied. A mixture of gangliosides completely inhibited the adsorption of diphtheria toxin on the cell membranes, both sensitive (HeLa cells, macrophages) and resistant (L-cells) to its action. Neuraminidase-treated gangliosides were less effective. Immobilized gangliosides adsorbed diphtheria toxin effectively in the presence of a protective colloid and detergent triton X-100. The results obtained suggest gangliosides to be diphtheria toxin receptors.