Purification and partial characterization of a lectin from Pedilanthus tithymaloides latex

Hitherto lectins from latex have reported amongst 4 genera i.e. Elaeophorbia, Euphorbia, Hura and Synadenium out of 900 genera possessing latex in plants. A galactose-specific lectin from the latex of Pedilanthus tithymaloides has been purified to homogeneity by affinity chromatography on Sepharose 4B, which is an additional latex generic source for lectins. It has approximately M(r) 62,000 with 14.5% carbohydrate. SDS-PAGE reveals three bands, indicating that the lectin contain three subunits. It agglutinates with and without trypsinized human, and rabbit erythrocytes, but not sheep erythrocytes. However, it agglutinates sialidase-treated sheep erythrocytes. This lectin possesses mitogenic activity with murine spleen lymphocytes but does not inhibiting protein synthesis in rabbit reticulocyte lysate.