Sialyl lewis x

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Sialyl lewis x

Identifiers
CAS number	[98603-84-0]
PubChem	643990
MeSH	sialyl+Lewis+x
Properties
Molecular formula	C₃₁H₅₂N₂O₂₃
Molar mass	820.744 g/mol
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Sialyl Lewis^X, also known as sialyl Le^X and SLe^X, is a tetrasaccharide carbohydrate, that is usually attached to O-glycans on the surface of the cells, and known to play a vital role in cell-cell recognition processes. Sialyl Lewis ^X is one of the most important blood group antigens and is displayed on the terminus of glycolipids that are present on the cell-surface. Sialyl Lewis ^X determinant, E-selectin ligand carbohydrate structure, is constitutively expressed on granulocytes and monocytes and mediates inflammatory extravasation of these cells. Resting T and B lymphocytes lack its expression and are induced to strongly express sialyl Lewis ^X upon activation. Sialyl Lewis ^X determinant is expressed preferentially on activated Th1 cells but not on Th2 cells.
Defective synthesis of the sialyl Lewis ^X antigen results in immunodeficiency. Defective synthesis can be caused by the loss of fucosyltransferase, impairing the glycosylation of the glycosphingolipid.

[edit] Sources

Stephen J Isles, Molecule of the Month: Sialyl Lewis X
Chen G, Osada H, Santamaria-Babi L, Kannagi R (2006). "Interaction of GATA-3/T-bet transcription factors regulates expression of sialyl Lewis X homing receptors on Th1/Th2 lymphocytes". Proc Natl Acad Sci U S A 103 (45): 16894–9. doi:10.1073/pnas.0607926103. PMID 17075044.