Antimicrobial Plant Lectins

Lectins are proteins or glycoproteins of non immune origin which have a wide distribution in animals, plants, and microorganisms. Their medicinal role extends from simple antimicrobial action to anti- tumour properties.In view of the advancement in understanding the potential medicinal role of the plant lectins, a lectin from the leaves of Prunella vulgaris was isolated, purified, partially characterized and its antimicrobial activity evaluated. The lectin is specific for galactose and N-acetyl-galactosamine The molecular weight of the lectin as determined by SDS-PAGE was 32500 Da and that estimated from Sephadex G-100 gel filtration column was 65000 Da indicating that the purified lectin is a homodimer. The purified lectin also shows a significant antimicrobial activity against the infectious agents of some common diseases such as Salmonella typhi, Klebseilla pnuemonea and Escherhia coli.