Immunoprecipitation and partial characterization of diphtheria toxin-binding glycoproteins from surface of guinea pig cells

Abstract

125I-Labeled membrane glycoproteins that specifically interact with diphtheria toxin and CRM197 protein--but not with diphtheria toxoid, fragment A of diphtheria toxin, or cholera toxin--were detected by use of the lactoperoxidase labeling technique followed by an immunoprecipitation system. These glycoproteins, which adhere to lentil lectin-Sepharose columns, are present on the surface of diphtheria toxin-sensitive guinea pig lymph node cells but are completely lacking on the surface of diphtheria toxin-resistant mouse L cells. The major 125I-labeled glycoprotein that interacts with diphtheria toxin exhibits anomalous behavior, characteristic of glycoproteins, when analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. This demonstration of the biochemical nature of specific diphtheria toxin binding membrane components raises the possibility that the detected components are diphtheria toxin receptors.