Purification and structural characterization of lectins from the cnidarian Bunodeopsis antillienis

Purification and characterization of two different lectins from the Mexican anemone Bunodeopsis antillienis are reported. These two lectins named Bunodeopsis antillienis agglutinin-A (BAA-A) and -B (BAA-B) presented the following characteristics: BAA-A was resolved as a component, with haemagglutinating activity for human blood type A (N-acetylgalactosamine–galactose–fucose), with a molecular weight of 28,900 obtained by means of mass spectrometry, showed an isoelectric point of 5.04 with a higher carbohydrate specificity for N-acetylgalactosamine (GalNAc). The analysis of the N-terminal revealed it is related to phosphoesterase and GTP binding protein. BAA-B mainly active with human blood type B (galactose–galactose–fucose) was resolved into three fractions (BAA-B1-3). Their molecular weight were: BAA-B(1) 39,350, BAA-B(2) 28,300 and BAA-B(3) 17,550. The estimated isoelectric points were 8.05, 4.66 and 6.60, respectively. Only fraction 3 exhibited haemagglutinating activity with a higher carbohydrate specificity for galactose and mannose. The analysis of the N-terminal pointed out it is related with phospholipase A2. We suggest these lectins could be related to a feeding strategy.