New rabbit erythrocyte specific mycelial lectins from Fusarium sp. With complex saccharide specificity

Abstract

Eight Fusarium sp. namely, F. acutatum, F. globosum, F. graminearum, F. lactis, F. nivale, F. proliferatum, F. pseudoanthophilum and F. robustum were screened for the presence of lectins by hemagglutination activity using human ABO, porcine, ovine, goat and rabbit erythrocytes. Mycelial extracts of all the fungal cultures except F. graminearum displayed unique lectin activity with only rabbit erythrocytes. Enzymatic treatment of rabbit erythrocytes with neuraminidase has significantly enhanced the titre of all the lectin-positive extracts of fungal cultures. In contrast, most of the lectins showed a decline in lectin activity with protease treated rabbit erythrocytes. Saccharide specificity studies have shown that majority of the lectins are inhibitory towards O-acetyl sialic acids. None of the lectins from Fusarium sp. were inhibited by dextran, meso-inositol, and N-acetyl-D-glucosamine. Most of the fungal cultures displayed highest hemagglutination activity during the 10th day of growth in broth cultures. The unique saccharide specificity of Fusarium sp. lectins can be used for elucidating their clinical role in glycobiology research.