DSL contains two chains of 40 kDa and 46 kDa joined by disulfide bonds. This lectin is free of a reported 32 kDa contaminant protein. The carbohydrate binding site recognizes (β-1,4) linked N-acetylglucosamine oligomers, preferring chitobiose or chitotriose over a single N-acetylglucosamine residue. This lectin binds well in the acidic pH range but its affinity decreases above pH 8.0.
DSL also binds well to N-acetyllactosamine and oligomers containing repeating N-acetyllactosamine sequences. A branched pentasaccharide including two N-acetyllactosamine disaccharides linked to mannose (β-1,6) and (β-1,2) was reported to be the most potent inhibitor of agglutination.