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.
Cy5, when bound to Sambucus nigra Lectin (SNA/EBL II), can show the binding pattern of this lectin in cellular imaging and flow cytometry. The excitation wavelength required for Cy5 to fluoresce is high enough to avoid overlap with most other fluorochromes, making it useful for dual-labeling experiments. Because of this high excitation, there is typically less background from autofluorescence of biological specimens.