Sambucus nigra lectin (EBL II/SNA II) isaffinity purified from elderberry bark. This lectin is a glycoprotein containing 7.8% carbohydrate and is not blood group specific. It is composed of two subunits and has a molecular weight of 140,000. EBL II has a specificity for carbohydrates containing terminal N-acetylgalactosamine and galactose residues.
The blood group A-active trisaccharide containing L-fucosyl group linked α1-2 to galactose is 10-fold lesser as an inhibitor than the parent oligosaccharide (GalNAc α1-3Gal), which suggests steric hindrance to binding by the α-L-fucosyl group and explains the failure of the lectin to exhibit blood group A specificity.
EBL II induces caspase-dependent apoptosis at low concentrations (nM) order, leading to typical symptoms of cell death in sensitive cells. This effect seems dependent on the carbohydrate binding B-chain.
Alkaline phosphatase (AP) is conjugated to Sambucus nigra Lectin (SNA/EBL II) to show the binding of SNA/EBL II in many applications including Western blotting and ELISA. Alkaline phosphatase is a large protein (140 kDa) that catalyzes the hydrolysis of phosphate groups from a substrate resulting in a colored or fluorescent product. The optimal enzymatic activity of this protein is between pH 8 and 10, and its reaction rate remains linear, improving sensitivity over time.