Purification and characterization of an N-acetyllactosamine-specific lectin from tubers of Arum maculatum.

A lectin was purified from the tubers of Arum maculatum (family Araceae) by affinity chromatography on a thyroglobulin-Sepharose column. The lectin is not a glycoprotein and has a subunit molecular weight of 14,600. It is specifically inhibited by N-acetyllactosamine (Gal beta 1,4GlcNAc), but is not significantly inhibited by monosaccharides or by lactose (Gal beta 1,4Glc), lacto-N-biose 1 (Gal beta 1,3GlcNAc), or chitobiose (GlcNAc beta 1,4GlcNAc). Asialoglycoproteins which contain N-acetyllactosamine structures are even more effective inhibitors of the lectin. This lectin should be a useful probe for N-acetyllactosamine groups in glycoproteins.