We have identified a receptor in hepatic endothelial and Kupffer cells that binds oltgosaccharides terminating with the sequence SO,-4GalNAcj31, 4GlcNAcj31, 2-Mana (S4GGnM). This receptor can account for the rapid removal of the glycoprotein hormone lutropln, which bears unfque Asn-linked oligosaccharides terminating In S4GGnM, from the circulation. Hepatlc endothelial cells express 579,000 S4GGnM receptors at their surface and bind lutropin with an apparent Kd of 1.63 x lo-’M. Bound ligand is rapidly internalized. Binding does not require divalent cations, is reversed by incubation at pH 5.0 or below, and is inhibited by fucoidin but not by hyaluronate, heparin, chondroltin sulfate, or dextran sulfate. We propose that the S4GGnMspeclflc receptor represents a major mechanism for clearance of certain sulfated glycoproteins from the blood, including members of the glycoprotein hormone family.