Lectins
Lectins are proteins characterized by their sugar-specificity. The capacity to recognize carbohydrates of the cell surface provides a very significant function of lectins in invertebrates (molluscs or tunicates), where the agglutinin capacity of lectins performs the role of immunoglobulins.
However, the ligand specificity there are several similarities of lectins it is problem, whether these lectins possess analogous or diverse chemotactic potential. In this relation a selection of lectins isolated from different taxons (Helix pomatia, Glycine max, Lens culinaris, Canavalia ensiformis-ConA and Phaseolus vulgaris-PHA) were studied in unicellular Tetrahymena (Kõhidai et al. Acta Microbiol.Immunol. Hung. 1996)
In the case of the N-acetyl-Gal specific lectin Helix a clear dose dependence was detected, while mannose specific Con-A showed a peak at 10-9 M. The oligosaccharide specific PHA showed two peaks, it has attractant effect at 10-11 and 10-6 M alike.