Carbohydrate-binding specificity of Tetracarpidium conophorum lectin.
The carbohydrate-binding specificity of a novel plant lectin isolated from the seeds of Tetracarpidium conophorum (Nigerian walnut) has been studied by quantitative hapten inhibition assays and by determining the behavior of a number of oligosaccharides and glycopeptides on lectin-Sepharose affinity columns. The Tetracarpidium lectin shows preference for simple, unbranched oligosaccharides containing a terminal Gal beta 1----4GlNAc sequence over a Gal beta 1----3GlcNAc sequence and substitution by sialic acid or fucose of the terminal galactose residue, the subterminal N-acetylglucosamine or more distally located sugar residues of oligosaccharides reduce binding activity. Branched complex-type glycans containing either Gal beta 1----4GlcNAc or Gal beta 1----3GlcNAc termini bind with higher affinity than simpler oligosaccharides. The lectin shows highest affinity for a tri-antennary glycan carrying Gal beta 1----4GlcNAc substituents on C-2 and C-4 of Man alpha 1----3 and C-2 of Man alpha 1----6 core residues. Bi- and tri-glycans lacking this branching pattern bind more weakly. Tetra-antennary glycans and mono- and di-branched hybrid-type glycans also bind weakly to the immobilized lectin. Therefore, Tetracarpidium lectin complements the binding specificities of well-known lectins such as Datura stramonium agglutinin, Phaseolus vulgaris agglutinin, and lentil lectin and will be a useful additional tool for the identification and separation of complex-type glycans.
Sato
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National Institute for Medical Research, Ridgeway, London, United Kingdom.
Animashaun
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Hughes
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D001212:Asialoglycoproteins; D050260:Carbohydrate Metabolism; D002846:Chromatography, Affinity; D060748:Fetuins; D006020:Glycopeptides / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D007118:Immunoassay; D037102:Lectins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism; D037121:Plant Lectins; D012639:Seeds; D013379:Substrate Specificity; D014197:Trees; D000509:alpha-Fetoproteins / Q000378:metabolism
D001212:Asialoglycoproteins; D060748:Fetuins; D006020:Glycopeptides; D006023:Glycoproteins; D037102:Lectins; D009844:Oligosaccharides; D037121:Plant Lectins; D000509:alpha-Fetoproteins; C017029:asialofetuin