A comparative study of snail galactans with the sponge lectins of axinella polypoides revealing some structural peculiarities of the helix pomatia galactan

Abstract

1. 1. The snail galactans of Helix pomatia and Biophalaria glabrata were isolated using immobilized dGal-specific lectins from the sponge Axinella polypoides. They contained about 0.8% N. 2. 2. Ten to thirty times higher amounts of polysaccharides were required for precipitin formation with the Axinella lectins, when compared with blood group substances or arabino galactan, though snail galactans are composed of the most complementary structure to the lectin combining site. Tightly packed dGal residues seem to be of sterical hindrance. 3. 3. The binding of Helix pomatia galactans to the affinity resin and the precipitin formation with the sponge lectins is affected stronly by Ca 2+, whereas other galactans do not show these effects. Complex formation of H.p. galactan molecules is suggested and N-containing negatively charged groups are expected to interact with Ca 2+.