Spacer-modified saccharides for the regioselective photoaffinity labelling of the binding site of an immunoglobulin.
The spacer-modified trisaccharides that mimic (1----6)-linked beta-D-galactotetraose (Gal4), namely, O-beta-D-galactopyranosyl-(1----6)-S-beta-D-galactopyranosyl-(1----11)-8 -azi- 6,7,8,9,10-pentadeoxy-11-thio-D-galacto-undecose (12) and O-beta-D-galactopyranosyl-(1----6)-O-beta-D-galactopyranosyl- (1----13)-8-azi-6,7,8,9,10,11,12-heptadeoxy-D-galacto-tri decose (20) were synthesised by coupling disaccharide derivatives with 8-azi-6,7,8,9,10-pentadeoxy-1,2:3,4-di-O-isopropylidene-11-O -tosyl-alpha-D-galacto-undecopyranose (10) and 8-azi-6,7,8,9,10,11,12-heptadeoxy-1,2:3,4-di-O-isopropyli den e-alpha-D-galacto- tridecopyranose (17), respectively. Compounds 12 and 20 had affinities for the combining sites of the antibodies IgA X24 and IgA J 539 similar to those of O-beta-D-galactopyranosyl-(1----6)-O-beta-D- galactopyranosyl-(1----11)-8-azi-6,7,8,9,10-pentadeoxy-D-gal acto-undecose (7) and the native ligand Gal4. Tritium-labelled 7 chemically modified the heavy and light chains of IgA J 539, whereas 8-azi-6,7,8,9,10-pentadeoxy-D-(11-3H)galacto-undecose (5a) reacted only with the heavy chain.
Lehmann
J
J
Institut für Organische Chemie und Biochemie, Universität Freiburg, Germany.
Scheuring
M
M
D000345:Affinity Labels / Q000138:chemical synthesis*; D001666:Binding Sites, Antibody / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005685:Galactans / Q000276:immunology*; D007070:Immunoglobulin A / Q000737:chemistry*; D008969:Molecular Sequence Data; D010777:Photochemistry; D014312:Trisaccharides / Q000737:chemistry*
D000345:Affinity Labels; D005685:Galactans; D007070:Immunoglobulin A; D014312:Trisaccharides