Purification and partial characterization of a lectin from Euphorbia neriifolia latex

A lectin was purified from Euphorbia neriifolia latex to homogeneity by affinity chromatography on Sepharose 4B. The protein appears to be a dimer with approximate M(r) of 60,000 on gel filtration and showing a single band at M(r) 32,000 in SDS-PAGE, and contains 12.3% carbohydrate. It agglutinated trypsinized human and rabbit erythrocytes, but not sheep erythrocytes. However, sialidase-treated sheep erythrocytes were agglutinated. The galactose and galactose containing sugars inhibited the heamagglutination with increased beta-anomeric specificity. The Euphorbia lectin possesses mitogenic activity with murine spleen lymphocytes but it does not inhibit protein synthesis in rabbit reticulocyte lysate.