Isolation and characterization of a bioactive lectin from Zizyphus oenoplia

Abstract

A lectin isolated from Zizyphus oenoplia leaves, agglutinating rabbit and human ‘B’ group erythrocytes, was purified to homogeneity by affinity chromatography on Guar gum column. The purified lectin showed single band, both in non-denaturing PAGE and SDS-PAGE. The molecular weight determined by SDS-PAGE was found to be 23000 Da. Treatment of lectin with 10 mM EDTA diminished the haemagglutinating activity to 50% of the original level.  Addition of divalent cations, Mg²⁺ and Mn²⁺ at 1mM totally restored hemagglutinating activity. The protein shows maximum activity over the pH range and was stable at higher temperature. It was identified to be a glycoprotein. The lectin has shown to promote proliferation of human lymphocytes after 72 h of culture under standard conditions. The purified lectin was also found to be pH and temperature stable.