Isolation of the SO4-4-GalNAcβ1,4GlcNAcβ1,2Manα-specific Receptor from Rat Liver

摘要: Abstract Glycoproteins, such as the glycoprotein hormone lutropin (LH), bear oligosaccharides terminating with sequence SO4-4GalNAcβ1,4GlcNAcβ1,2Manα (S4GGnM) and are rapidly removed from circulation by a receptor present in hepatic endothelial cells Kupffer cells. Rapid removal is essential for attaining maximal activity vivo. We have isolated protein rat liver which has properties expected S4GGnM-specific (S4GGnM-R). The S4GGnM-R closely related to macrophage mannose (Man-R) both antigenically structurally. At least 12 peptides prepared amino acid sequences that identical those of Man-R. Nonetheless, ligand binding Man-R differ number respects. binds immobilized LH but not mannose, whereas LH. When analyzed using assay precipitates complexes polyethylene glycol, able bind S4GGnM-bovine serum albumin (S4GGnM-BSA) conjugates not. In contrast Man-BSA. Monosaccharides inhibit Man-BSA enhance S4GGnM-R. Oligosaccharides S4GGnM Man bound at independent sites on may account clearance glycoproteins bearing either fucose, orN-acetylglucosamine.