The hepatic asialoglycoprotein receptor.

Asialo- (i.e., galactose-terminal) glycoproteins are specifically and avidly recognized by a mammalian hepatic parenchymal cell receptor. This receptor, itself a glycoprotein, binds ligand molecules and directs their delivery to lysosomes for catabolism. The receptor is reutilized during this process of receptor-mediated endocytosis. Ligand specificity is conferred by galactose or N-acetyl-galactosamine at the nonreducing termini of the oligosaccharide chains. The receptor appears to be a transmembrane protein and is localized both to the cell surface as well as to several membranous intracellular compartments.