Purification and partial characterization of a lectin from the fresh leaves of Kalanchoe crenata (Andr.) Haw.

A haemagglutinating protein from the saline extracts of Kalanchoe crenata leaves, which agglutinate all human blood types, was purified to homogeneity by ion-exchange chromatography on a DEAE-Cellulose column followed by gel filtration on a Sephadex G-100 column. The purified protein showed one band, both in non-denaturing PAGE and SDS-PAGE. The M(r) that was determined by SDS-PAGE was 44,000 Da and that estimated from gel filtration was 47,000. Treatment of the haemagglutinating protein with 5 mM EDTA diminished the haemagglutinating activity to 50% of the original level. The addition of divalent cations, 10 mM Mg(2+), 10 mM Mn(2+), or 10mM Ba(2+), totally restored and enhanced the activity. The protein showed maximum activity over the 3-7 pH range and was heat-resistant. It was also a glycoprotein containing about 1.5% carbohydrate.