|
Ricinus communis agglutinin I is a glycoprotein with a molecular weight of 120,000. The native lectin is moderately toxic and consists of two subunits of 60,000 daltons which can be dissociated by reducing agents into closely related chains between 27,000 and 33,000 daltons. One of the chains appears to be common to the “B” chain of another castor bean lectin, ricin, while the other chain is unique to RCA120. The lectin binds preferentially to oligosaccharides ending in galactose but may also interact with N-acetylgalactosamine. Many glycoproteins have been purified using this lectin since galactose is a common constituent of their oligosaccharide chains. Often, desialylation of the glycoprotein is required first because most glycoproteins have terminal sialic acid residues which can block lectin binding.
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. |