Novel sulfated gangliosides, high-affinity ligands for neural siglecs, inhibit NADase activity of leukocyte cell surface antigen CD38

Three kinds of novel sulfated gangliosides structurally related to the Chol-1 (α-series) ganglioside GQ1bα were synthesized. These sulfated gangliosides were potent inhibitors of NADase activity of leukocyte cell surface antigen CD38. Among the synthetic gangliosides, GSC-338 (II3III6-disulfate of iso-GM1b) was surprisingly found to be the most potent structure in both the NADase inhibition and MAG-binding activity. The present study indicates that the sulfated gangliosides are useful to study the recognition of the internal tandem sialic acid residues α2-3-linked to Gal(II3) as well as the siglec-dependent recognition including a terminal sialic acid residue.