Studies on the Diphtheria Toxin Receptor

Abstract

¹²⁵ I-Labeled membrane components that specifically interact with diphtheria toxin were detected by two different labeling methods followed by an immunoprecipitation system. These components, which adhere to lentil lectin-agarose columns, were present on the surface of diphtheria toxin-sensitive Vero cells but were not detected on the surface of diphtheria toxin-resistant L-929 cells. Cell density experiments using Vero cells showed that the availability of the diphtheria toxin receptor was cell density independent. Solubilization experiments were also performed demonstrating that the diphtheria toxin receptor could be solubilized and still maintain its ability to block the association of diphtheria toxin to whole Vero cells.