Roles of the structural units, glycotopes / mammalian N-glycans for Con A - Glycan interactions, their codes, and their recognition Factors

Abstract The binding property of Con A has been studied intensively and applied widely to glycoconjugates / glycobiology for over 80 years. However, its role and functional relationship of Con A with these mammalian structural units, glycotopes, N -glycan chains, as well as their polyvalent forms in N -glycoproteins involved in the Con A- glycan interactions have not been all defined and organzied. In this study, the recognition factors involved in these inteactions were azalyzed by our well developed method- the enzyme linked lectinosorbent (ELLSA) and inhibition assay. Based on all data obtained, it is concluded that Con A, as previous report, has a relatively broad and wide recognition ability with the Manα1→ and Glcα1→ related glycans. In addition to it reacted strongly with yeast mannan and glycogens, it also bound well with a large number of mammalian N -glycans, including the N -glycans of rat sublingual gp (RSL), human Tamm-Horsfall glycoprotein (THGP), thyroglobin and lactosferrin. The recognition specificity of Con A towards ligands, expressed by M olar R elative P otency (Molar R.P.), in a decreasing order is as follows: a1→3, a1→6 Mannopentaose ( M 5 ) and Biantennary N -linked core pentasaccharide ( M Di ) ≥ a1→3, a1→6 Mannotriose ( M 3 ) > Mana1→3Man (α1→3Mannobiose), Mana1→2Man (α1→2Mannobiose), Mana1→6Man (α1→6Mannobiose), Mana1→4Man (α1→4Mannobiose) > GlcNAcb1→2 Man (b1→2 N-Acetyl glucosamine-mannose) > Mana1→/Glcα1→ > Man > Glc, while Gal / GalNAc were inactive. Furthermore, the Man related code system, in this study, is proposed to express by both numbers of Man and GlcNAcb1→ branches ( M 3 to M 9 / M Mono to Penta etc. ) and a table of three Mana1→ and Glca1→ related biomasses of six recognition factors involved in the Con A-glycan interactions has also been demonstrated. These themes should be one of the most valuable advances since 1980s.