| abstract |
Tyrosine sulfate on PSGL-1, particularly at least one of residues (46, 48) and (51), functions in conjunction with sialylated and fucosylated glycans, most preferably Thr-57, to mediate high affinity binding to P-selectin. PSGL-1 O-glycans have been determined to consist of disialylated or neutral forms of the core-2 tetrasaccharide Gal.beta.14G1cNAc.beta.16(Gal.beta.13)GalNAcOH. A minority of the O-glycans are .alpha.1,3 fucosylated that occur as two major species containing the sialyl Lewis x antigen - one species is a disialylated, monofucosylated glycan of formula (I), and the other is a monosialylated, trifucosylated glycan having a polylactosamine backbone of formula (II), wherein R = H, OH, another sugar or an aglycone such as an amino acid. |