Specificity of binding of three soluble rat lung lectins to substituted and unsubstituted mammalian beta-galactosides.

摘要: Binding of a series mammalian glycoconjugates to three soluble rat lung lectins was determined with quantitative assay. The lectins, RL-14.5, RL-18, and RL-29, had similar apparent affinity for lactose associated the same critical determinants, which included positions 4 6 Gal part Glc. Derivatization at position 3 Glc in markedly reduced reactivity lectins. For RL-14.5 RL-29 determinant extended specifically 3-hydroxyl must be equatorial. In contrast, stereochemical requirements RL-18 were less specific, beta 1-3GalNAc bound as well lactose. activity enhanced by GalNAc alpha 1-3 substitution on Gal, modification little effect inhibited binding RL-14.5. Combinations these residues larger oligosaccharides glycopeptides did not substantially enhance above that might expected from sum constituent beta-galactoside residues. Although showed overlapping specificities, their properties are sufficiently different suggest selective interactions naturally occurring glycoconjugates.