This lectin is a 150,000 molecular weight tetrameric glycoprotein consisting of four disulfide-linked chains, two of about 36,000 daltons and two of about 38,000 daltons. Sambucus nigra lectin binds preferentially to sialic acid attached to terminal galactose in (a-2,6), and to a lesser degree, (a-2,3), linkage. Binding is also inhibited to some extent by lactose or galactose. This lectin does not appear to bind sialic acid linked to N-acetylgalacto-samine. SNA has been reported to inhibit cell-free protein synthesis. This biotinylated lectin conjugate is prepared from affinity-purified lectin and is optimally labeled with biotin. Essentially free of inactive lectin conjugate and containing no free biotin, this biotinylated lectin provides an ideal intermediate for examining glycoconjugates using the Biotin-Avidin System. First the biotin-labeled lectin is added, followed by the VECTASTAIN® ABC Reagent, Avidin D conjugate, or streptavidin derivative. Another possible application is in the isolation of lymphokines and other products of mitogenic stimulation. |