1. Binding of 125I-crude gluten digest (Frazer's fraction III, FF-III) and 125I-concanavalin A (Con A) to isolated rat enterocytes and of 125I-FF-III to human enterocytes was investigated.
2. Specific binding of 125I-FF-III to rat enterocytes was observed but binding was not inhibited by any of a range of simple and complex saccharides, although casein and bovine serum albumin displaced FF-III at high concentrations.
3. Con A also bound to enterocytes in a specific manner and was inhibited by α-methyl-D-mannoside, confirming a lectin-mediated interaction.
4. 125I-FF-III exhibited quantitatively similar specific binding to both normal human and coeliac enterocytes.
5. The primary interaction of gliadin peptides with the enterocyte surface membrane is not lectin-mediated and unlikely to be of fundamental importance in the pathogenesis of coeliac disease.