Isolation of a homodimeric lectin with antifungal and antiviral activities from red kidney bean (Phaseolus vulgaris) seeds

A homodimeric lectin adsorbed on Affi-gel blue gel and CM-Sepharose and possessing a molecular weight of 67 kDa was isolated from red kidney beans. The hemagglutinating activity of this lectin was inhibited by glycoproteins but not by simple sugars. The lectin manifested inhibitory activity on human immunodeficiency virus-1 reverse transcriptase and alpha -glucosidase. The N-terminal sequence of the lectin exhibited some differences from previously reported lectins from Phaseolus vulgaris but showed some similarity to chitinases. It exerted a suppressive effect on growth of the fungal species Fusarium oxysporum, Coprinus comatus, and Rhizoctonia solani. The lectin had low ribonuclease and negligible translation-inhibitory activities.