ECL consists of two subunits with molecular weights of 28,000 and 26,000, and an isoelectric point between pH 6.3 and 6.5. It is reported to be mitogenic for human peripheral blood T lymphocytes and has specificity for blood group A(-SA).

The carbohydrate structure ECL binds is frequently found in membrane and serum glycoproteins of mammalian cells. Studies show that GalNAc is an active ligand but its polyvalent structural units are poor inhibitors. The shape of the lectin binding domains may resemble cavity type with Galbeta1->4GlcNAc as the core binding site with additional one to four sugar subsites, and is most complementary to a linear trisaccharide. Some Galbeta1-related oligosaccharides are the major structures for lectin binding. This lectin has an affinity for D-galactose and D-galactosides and elutes with the sugar lactose.