Artificial glycopolypeptide conjugates: simple synthesis of lactose- and N, N′-diacetylchitobiose-substituted poly( l-glutamic acid)s through N- β-glycoside linkages and their interaction with lectins

• Published in: Biochimica et biophysica acta Vol. 1336; no. 2; pp. 117 - 122
• Main Authors: Kobayashi, Kazukiyo, Tawada, Emiko, Akaike, Toshihiro, Usui, Taichi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 29.08.1997
• Subjects: Biomedical material; Glycopeptides - chemical synthesis; Glycopeptides - metabolism; Glycopolypeptide; Glycotechnology; Hemagglutination; Humans; Lactose; Lectin; Lectins - metabolism; Polyglutamic Acid - chemical synthesis; Polyglutamic Acid - metabolism; RCA 120, Ricinus communis; Lectin; HOBt, 1-hydroxybenzotriazole; BOP, benzotriazol-1-yl-oxy-tris(dimethylamino)-phosphonium hexafluorophosphate; PyBOP, benzotriazol-1-yl-oxy-tripyrrolidinophosphonium hexafluorophosphate; PNA, Arachis hypogaea (peanut lectin); HBTU, O-(benzotriazol-1-yl)- N, N, N′ N′-tetramethyluronium hexafluoro-phosphate; Biomedical material; Glycotechnology; WGA, Triticum vulgaris (wheat germ agglutinin); Glycopolypeptide; DBP, diphenyl(2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate; DSA, Datura stramonium (Jimson weed lectin)
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/S0304-4165(97)00018-4

Poly(glutamic acid)s carrying lactose- and N, N′-diacetylchitobiose residues were synthesized via a simple two-step procedure. The oligosaccharides were treated with ammonium hydrogen carbonate and the resulting N- β-glycosylamine was coupled with pendant carboxyl groups of poly( l-glutamic acid) in the presence of a mixture of benzotriazol-1-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) and 1-hydroxybenzotriazole (HOBt) in dimethyl sulfoxide. The oligosaccharide incorporated as pendant N-glycosides was estimated by 1H-NMR spectroscopy to be 30 mol% (or 45 wt%) for lactose and 27 mol% (46 wt%) for chitobiose. The glycopolypeptide carrying N, N′-diacetyl-chitobiose inhibited hemagglutination activity of wheat germ agglutinin (WGA) much more strongly (about 10 6 times) than N, N′-diacetylchitobiose itself. The high activity is due to the cluster or high density effect of the glycopolypeptides.