Receptors for fucose‐binding proteins of Lotus tetragonolobus isolated from mouse embryonal carcinoma cells

Receptors for fucose‐binding proteins of Lotus tetragonolobus were isolated from N4‐1 and F9 embryonal carcinoma cells. They were glycoproteins, whose major components had apparent relative molecular masses of more than 1. Carbohydrates released from the receptors of N4‐1 cells by hydrazinolysis were separated into three fractions by gel filtration. Binding activity to the lectin was detected in the high‐molecular‐mass fraction. The composition of the large glycan was characteristic of the poly ( N ‐acetyllactosamine)‐type, and glucosamine was identified as the sugar involved in the protein‐carbohydrate linkage. The glycan has one fucosyl residue per four N ‐acetyllactosamine units. Most of the fucose was linked to the C‐3 hydroxyl group of N ‐acetylglucosamine. No Fucα1→2Gal or Fucα1→4GlcNAc linkage was detected. The glycan had a relative molecular mass of 9000 or more and the poly ( N ‐acetyllactosamine) units were branched. N ‐Acetylgalactosamine residues were detected in non‐reducing ends of at least a part of the glycan. Therefore, the glycan has a more complex structure than the related one from human granulocytes, although both of them have Fucα1→3GlcNAc termini.