Lehmann J, Weitzel UP. Synthesis and application of alpha-D-mannosyl clusters as photoaffinity ligands for mannose-binding proteins: concanavalin A as a model receptor.
Carbohydr Res 1996;
294:65-94. [PMID:
8962487 DOI:
10.1016/s0008-6215(96)90619-9]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mono-, di-, and tri-antennary alpha-D-mannopyranosyl derivatives were synthesized as oligosaccharide mimics. The compounds vary in the length of the acyclic aglyconic spacers linking, in the case of the di- and tri-antennary derivatives, the glycosyl endgroups. By haemagglutination assay (Coombs test) the affinity of the alpha-D-mannopyranosyl ligands against Con A was determined in comparison with methyl alpha-D-mannopyranoside. Affinity enhancement and strong cross-linking capacity were found with the di- and tri-antennary compounds where alpha-D-mannopyranosyl endgroups are separated by spacers of 5-37 atoms in length. The optimal ligand had Ki of 5.1 microM in comparison with 3.12 microM for methyl alpha-D-mannopyranoside. The monoantennary compound and, to certain extents, one di- and short tri-antennary ligands with short spacer lengths did not differ significantly in affinity from methyl alpha-D-mannopyranoside. A triantennary, radiolabelled ligand equipped with a photolabile diazirino group was used to covalently modify Con A by photoaffinity labelling. A significant degree of covalent cross-linking of Con A monomers was observed.
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