Abstract

ISOLATION AND CHARACTERIZATION OF LECTIN FROM SEEDS OF ZIZYPHUS MAURITIANA

Ashwin B. Butle and Mandakini B. Patil*

Abstract

The present paper deals with isolation and characterization of a novel galactose binding lectin from the seed cotyledons of Zizyphus mauritiana. The extracted lectin in PBS at pH 7.00 was fractionated by Ammonium sulphate precipitation. The fraction obtained between 0 – 35% ammonium sulphate precipitation was further purified by affinity chromatography on guar-gum followed by ion exchange chromatography on DEAE-cellulose. The isolated lectin was found to be tripeptide, molecular weight of three different subunits of 38 kD, 25 kD and 19.95 kD on SDS - PAGE. Isolated lectin agglutinated rabbit erythrocytes showing maximum agglutination with human B+ erythrocytes. It was active between pH 4.0 - 9.0 with an optimum activity at pH 7.0 and was found fairly stable from pH 4.5 to 8.0. The lectin optimally active at 37°C was stable up to 80°C. Presence of metal ions such as Mg++ and Mn++ positively influenced the activity of lectin but the activity was inhibited in the presence of Cd++, Hg++ and Pb++. The lectin showed maximum enzymatic activity towards the substrate β – oNPGal.

Keywords: Lectin, Zizyphus, erythrocyts, affinity chromatography, agglutinin.