А new Gal/GalNAc-specific lectin from the mussel Mytilus trossulus: Structure, tissue specificity, antimicrobial and antifungal activity

In the present study, a new Gal/GalNAc specific lectin from the mussel Mytilus trossulus (designated as MTL) was identified, and its expression levels, both in tissues and toward pathogen stimulation, were then characterized. The MTL primary structure was determined via cDNA sequencing. Deduced sequence of 150 amino acid residues showed 89% similarity to lectins from the mussels Crenomytilus grayanus and Mytilus galloprovincialis that were the first members of a new family of zoolectins. The results indicated that the MTL might be involved in immune response toward pathogen infection, and it might perform different recognition specificity toward bacteria or fungi.

A lectin with antifungal activity from the mussel Crenomytilus grayanus

Lectins (carbohydrate-binding proteins) are well known to actively participate in the defense functions of vertebrates and invertebrates where they play an important role in the recognition of foreign particles. In this study, we investigated of in vitro antifungal activity of lectin from the mussel Crenomytilus grayanus (CGL). Enzyme-linked immunosorbent assay indicated that CGL was predominantly detectable in tissues of mantle and to a lesser degree in the tissues of muscle, hepatopancreas, gill and hemocytes. After challenged by Pichia pastoris the level of CGL was upregulated and reached the maximum level at 12 h post challenge and recovered to the original level at 24 h. The lectin was capable of inhibiting the germination of spores and hyphal growth in the fungi. All these results indicated that CGL is involved in the innate immune response in mollusc animals.