- Cell surface glycan
- Applications: decoy glycan for the development of antivirals and antibacterial agents
6′-Sialyl N-acetyl-D-lactosamine (6′-sialyllactosamine or 6′-SLN) is a trisaccharide in which N-acetylneuraminic acid (sialic acid) is attached via an α2,6 linkage to the C6 hydroxyl of galactose in N-acetyllactosamine. This structure is the positional isomer of 3′-sialyl LacNAc, differing only in the attachment point of the sialic acid residue. Despite this seemingly minor structural difference, 6′-sialyl LacNAc has profoundly different biological properties, receptor interactions, and downstream biosynthetic potential compared to its α2,3-linked counterpart.
The α2,6-sialylated glycan occupies a central position in human biology and infectious disease. It serves as the preferred receptor for human-adapted influenza viruses, whose hemagglutinins have evolved to recognize the distinctive conformation of α2,6-linked sialic acid present in the human upper respiratory tract. Beyond viral recognition, 6′-sialyl LacNAc is the ligand for CD22 (Siglec-2), a critical inhibitory receptor on B lymphocytes that modulates B cell activation thresholds.
