Sabella spallanzanii mucus contain a galactose-binding lectin able to agglutinate bacteria. Purification and characterization
Keywords:mucus, hemagglutinin, bacteria, lactose-bindgaing lectin, S. spallanzanii
Lectins are present in almost all living organisms and are involved in several biological processes, including immune responses. In the present study, a calcium dependent galactose-binding lectin exhibiting an apparent MW of 43 kDa has been characterized and purified from the mucus of the polychaete Sabella spallanzanii by using both affinity chromatography and high-pressure liquid chromatographic methods. Its agglutinating activity towards rabbit erythrocytes was significantly modified by the addition of calcium or EDTA. The activity was optimal at temperature values comprised between 4 and 18 °C, maintain a 50% of activity between 20 and 37 °C, was significant deleted after exposure at 50 °C, and was depleted at 90 °C. The S. spallanzanii Galactose-Binding Lectin (SsGBL) was able to agglutinate bacteria and to preferentially recognize Gram-negative bacteria. The strongest agglutinating activity was observed towards Vibrio alginolyticus and Escherichia coli, by contrast mucus agglutinated in a lesser extent both Aeromonas hydrophyla and the Gram-positive Micrococcus lysodeikticus thus suggesting its involvement in host pathogen interactions.