PURIFICATION OF A FUNCTIONAL RECEPTOR FOR CLOSTRIDIUM-DIFFICILE TOXIN-A FROM INTESTINAL BRUSH-BORDER MEMBRANES OF INFANT HAMSTERS

A receptor for Clostridium difficile toxin A was purified from brush b order membranes (BBMs) from the small intestine of infant hamsters. Th e BBMs were solubilized with Triton X- 1 14, and the solubilized recep tor was purified with use of a toxin A immobilized affinity-chromatogr aphy column and differential temperature elution. SDS-PAGE and silver staining of the purified receptor revealed numerous high-molecular-wei ght bands. However, ligand blotting analysis with I-125-toxin A used a s the probe identified a 163-kD protein as the predominate toxin A-bin ding molecule. Toxin A bound to the purified receptor at physiological temperature, but the amount of toxin bound increased at lower tempera tures. Bovine thyroglobulin bound to toxin A and inhibited its binding to the purified receptor. Preincubation of the receptor with lectins produced by Bandeirea simplicifolia or Datura stramonium reduced speci fic binding by I-125-toxin A. Our data indicate that the purified toxi n A receptor from small intestine BBMs of infant hamsters is a galacto se- and N-acetylglucosamine-containing glycoprotein.