Carbohydrate binding specificity of a beetle (Allomyrina dichotoma) lectin.
Carbohydrate binding specificity of a lectin, allo A, isolated from a beetle (Allomyrina dichotoma), was investigated by means of lectin affinity chromatography. Sialylated complex-type and hybrid-type oligosaccharides/glycopeptides, and sialyllactose were retained by the column, whereas desialylated ones were retarded but not retained by the column. The association constants of allo A for biantennary oligosaccharides from human serum transferrin, determined by frontal analysis, were 8.0 X 10(5) M-1, 4.5 X 10(5) M-1, and 2.5 X 10(5) M-1 for disialo-, monosialo-, and asialo-oligosaccharides, respectively. Removal of the beta-galactose residues markedly reduced the association constant to 3.5 X 10(3) M-1. Furthermore, allo A was found to have no affinity for mucin-type glycopeptides carrying the sialylated Gal beta 1----3 GalNAc sugar sequence (Ka: 3.5 X 10(3) M-1). The results of this study indicated that allo A strongly binds to the trisaccharide structure, NeuAc alpha 2-3(6)Gal-beta 1-4GlcNAc, and that its binding potency is affected by the inner core structures of oligosaccharides and glycopeptides, because the presence of a bisecting N-acetyl-glucosamine residue and an alpha-fucose residue linked to the innermost N-acetylglucosamine residue reduced the association constants for oligosaccharides and glycopeptides.
Sueyoshi
S
S
Division of Chemical Toxicology and Immunochemistry, Faculty of Pharmaceutical Sciences, University of Tokyo.
Yamamoto
K
K
Osawa
T
T
D000818:Animals; D050260:Carbohydrate Metabolism; D002846:Chromatography, Affinity; D001517:Coleoptera; D006020:Glycopeptides / Q000378:metabolism; D037102:Lectins / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism
C045794:Allomyrina lectin; D006020:Glycopeptides; D037102:Lectins; D009844:Oligosaccharides