Ligand recognition by purified human mannose receptor.
In this work we examine the carbohydrate binding properties of human placental mannose receptor (HMR) using a rapid and sensitive enzyme-linked immunosorbent microplate assay. The assay is based on the inhibition of binding of highly purified receptor to yeast mannan-coated 96-well plates. The specificity of ligand binding was inferred from the potency of different saccharides in blocking HMR binding to the mannan-coated wells. The relative inhibitory potency of monosaccharides was L-Fuc greater than D-Man greater than D-Glc greater than D-GlcNAc greater than Man-6-P much greater than D-Gal much greater than L-Rha much greater than GalNAc. The inhibitory potency of mannose increased by two orders of magnitude when linear oligomers were used. Oligomers containing alpha-1-3- and alpha-1-6-linked mannose residues were more inhibitory than those containing alpha-1-2- and alpha-1-4-linked mannoses. Linear or branched oligomannosides larger than three units did not have a significant influence on their inhibitory potency; rather, potency was found to decrease in comparison with oligomannosides with three units. Compared to linear oligomers, inhibition of binding was the best using branched mannose oligosaccharides, alpha-D-Man-bovine serum albumin conjugates, or mannan. A model is discussed in which branched ligand is bound to spatially distinct sites on the HMR.
Kéry
V
V
Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110.
Krepinský
J J
JJ
Warren
C D
CD
Capek
P
P
Stahl
P D
PD
D001667:Binding, Competitive; D002240:Carbohydrate Sequence; D006801:Humans; D066298:In Vitro Techniques; D037181:Lectins, C-Type; D008024:Ligands; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic / Q000378:metabolism*; D013329:Structure-Activity Relationship
D037181:Lectins, C-Type; D008024:Ligands; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009844:Oligosaccharides; D011134:Polysaccharides; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic