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

• Published in: Glycoconjugate journal 2023-10, Vol.40 (5), p.587-608
• Main Author: Wu, Albert M.
• Format: Article
• Language: English
• Subjects: Biochemistry; Biomedical and Life Sciences; Blood groups; Carbohydrates; Cysts; Enzymes; Glucosamine; Glycoconjugates; Glycoproteins; Lactoferrin; Lectins; Life Sciences; Mannan; Mannose; N-glycans; Pathology; Polysaccharides; Thyroglobulin
• ISSN: 0282-0080; 1573-4986
• DOI: 10.1007/s10719-023-10129-4

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 well defined and organized. In this study, the recognition factors involved in these interactions were analyzed by our well developed method- the enzyme linked lectinosorbent (ELLSA) and inhibition assay. Based on all the data obtained, it is concluded that Con A, as previously reported, has a relatively broad and wide recognition ability of the Manα1 → and Glcα1 → related glycans. It reacted not only strongly with yeast mannan and glycogens, but 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), thyroglobulin and lactoferrin. 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: α1 → 3, α1 → 6 Mannopentaose ( M 5 ) and Biantennary N -linked core pentasaccharide ( M Di ) ≥ α1 → 3, α1 → 6 Mannotriose ( M 3 ) > Manα1 → 3Man (α1 → 3Mannobiose), Manα1 → 2Man (α1 → 2Mannobiose), Manα1 → 6Man (α1 → 6Mannobiose), Manα1 → 4Man (α1 → 4Mannobiose) > GlcNAcβ1 → 2 Man (β1 → 2 N-Acetyl glucosamine-mannose) > Manα1 → /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 GlcNAcβ1 → branches ( M 3 to M 9 / M Mono to Penta etc. ) and a table of three Manα1 → and Glcα1 → 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.