Abstract

ISOLATION AND PURIFICATION OF A LECTIN FROM SEEDS OF A DROUGHT RESISTANT PLANT, CARAGANA GERARDIANA AND EVALUATION OF ITS ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES

*Aijaz Ahmad Ganaie, Ravi Prakash Mishra and Aashiq Hussain Allaie

Abstract

A galactose-specific lectin was purified from seeds of a droughtresistant leguminous plant, Caragana gerardiana, by affinitychromatography on lactose–agarose. Protein extract agglutinatedhuman erythrocytes (treated with proteolytic enzyme). Among variouscarbohydrates tested, the lectin induced agglutination was inhibited byD-galactose. SDS-PAGE showed that the lectin, named CGL producea single band establishing that the lectin is composed of similar type ofsubunits. The lectin was reasonably thermostable showing full activitywithin a temperature range of 20°C to 90°C. pH stability of the lectinfalls in the range of 2-9. The antimicrobial activity of the purifiedlectin was carried out by agar ditch diffusion method at differentconcentrations using appropriate standards. CGL demonstrated aremarkable antibacterial activity against the pathogenic bacteria Pseudomonas aeroginosa,Staphylococcus aureus, Escherichia coli, and Bacillus subtilis. Antioxidant activity of thepurified lectins were carried out by DPPH- free radical scavenging activity (DPPH assay) andFerric (Fe3+) reducing power assay.

Keywords: Lectin, DPPH, Caragana gerardiana.