Alpha-D-galactose-binding lectin (PubMed:27187419, PubMed:23093409, PubMed:27321048). Binds D-GalNAc, but not glucose or its derivatives (PubMed:27321048). Has hemagglutinating activity towards rabbit erythrocytes (PubMed:23093409, PubMed:27321048). Agglutinates bacteria. Has bacteriostatic activity on both Gram-positive and Gram-negative bacteria including B.subtilis, S.aureus, E.coli and V.parahaemolyticus, respectively (PubMed:27187419). Has a dose-dependent cytotoxic effect on the human globotriaosylceramide (Gb3)-expressing Epstein-Barr virus (EBV)-positive Burkitt's lymphoma (Raji) cell line (PubMed:23093409, PubMed:27321048). Has dose-dependent cytotoxic effect on another Burkitt's lymphoma (Ramos) cell line, which does not possess the EBV genome, but also expresses Gb3. Binds to Gb3 in these cells leading to phosphorylation of MEK1/2, ERK1/2, JNK and p38 kinase, activation of caspase-9/3 and to expression of p21 and tumor necrosis factor (TNF)-alpha (PubMed:26694420). No cytotoxic effect on the human chronic myelogenous leukemia (K-562) cell line, which does not express Gb3 (PubMed:23093409, PubMed:26694420). May be involved in innate immunity acting as an antibacterial or antifungal agent (PubMed:26694420, PubMed:27321048). May be a pattern recognition receptor (PRR) involved in recognition of glycans found on parasitic or symbiotic microorganisms (PubMed:27187419). Agglutination of E.coli is inhibited by alpha-galactoside melibiose, but not by beta-galactoside lactose. Homodimer. Highest expression in the posterior part of the mantle. Highly expressed in gills and to a lesser extent in mid mantle and anterior muscle. Lowest expression in digestive gland and posterior adductor muscle. Scarcely detectable in hemocytes. The mass determined is that of range 39-187. This protein may have potential for the development of new diagnostic agents or treatments for cancer since Gb3 is a cell-surface marker expressed by several different cancer cell lines. Was originally thought to be a monomer in solution on the basis of gel filtration.