Anti-Human CD57, FITC conjugated, clone HNK-1

CD57, also known as HNK-1, NK-1, and Leu-7 is a 100-115 kD oligosaccharide antigenic determinant expressed on a variety of proteins, lipids, and chondroitin sulfate proteoglycans. CD57 is expressed on a subset of peripheral blood lymphocytes, including NK cells and CD8+ T cells, and is also expressed on neural cells and striated muscle. CD57 is not expressed on red blood cells, granulocytes, monocytes, or platelets. While the function of CD57 is unknown, binding to L-selectin, P-selectin, and a fragment of laminin suggests that CD57 may be involved in cell-matrix interactions. CD57 is increased in some disease states associated with CD4/CD8 imbalances (AIDS, autoimmune disease, viral infections, and allograft transplants). Protein function: Involved in the biosynthesis of L2/HNK-1 carbohydrate epitope on glycoproteins. Can also play a role in glycosaminoglycan biosynthesis. Substrates include asialo-orosomucoid (ASOR), asialo- fetuin, and asialo-neural cell adhesion molecule. Requires sphingomyelin for activity: stearoyl-sphingomyelin was the most effective, followed by palmitoyl-sphingomyelin and lignoceroyl- sphingomyelin. Activity was demonstrated only for sphingomyelin with a saturated fatty acid and not for that with an unsaturated fatty acid, regardless of the length of the acyl group. [The UniProt Consortium]