RECOMBINANT GALECTIN-1 RECOGNIZES MUCIN AND EPITHELIAL-CELL SURFACE GLYCOCALYCES OF GASTROINTESTINAL-TRACT

Rdt gastrointestinal (GI) tract is rich source of galectins, a family of mammalian galactoside-binding lectins. To determine which tissue co mponent is the relevant glycoconjugate ligand for the galectins, we pr oduced recombinant galectin-1 and surveyed its binding sites on tissue sections of rat GI tract. Mucin and epithelial surface glycocalyces o f both gastric and intestinal mucosa were intensely stained. This find ing raises the possibility that some GI tract galectins known to be se creted by the epithelia may recognize these glycoconjugates and crossl ink them into a macromolecular mass. This galectin-ligand complex may play a role in protecting the epithelial surface against luminal conte nts such as gastric acid, digestive enzymes, and foreign organisms.