The heat treatment did not destroy all of the extract bioactivity but decreased the impact of these fractions on population growth. This is consistent with the hypothesis that the active component is a protein. This suggests the bioactive component may be spread over a range of fractions as is often the case with fractions isolated by chromatographic methods. The greatest activity was present in fractions 5 and 6. Haemagglutination is a general characteristic of lectins.
Some lectins can influence the behavior of nematodes.
The ingestion of lectins may cause damage to the epithelial cells and interfere with nematode metabolism. Stimulatory activity without lectin binding was present in the fraction below 10,000 molecular weight. All Centricon retentates possessed inhibitory activity and haemagglutination, while stimulatory activity with out haemagglutination was observed with the Centricons filtrates. This stimulatory activity apparently has a molecular weight below 10,000. SDS-PAGE analysis was performed on the protein extracts and heavy banding above the 50,000 M.W. size range was observed corresponding to inhibitory activity in the Centricon fractions.