Recombinant corresponding to aa42-295 from human CD162 expressed in CHO cell line.
Human PSGL-1, also CD162), is a 120kD mucin-type glycoprotein that plays a key role in leukocyte adhesion. It is synthesized as a 412aa preproprecursor that contains a 17aa signal sequence, a 24aa propeptide, a 279aa extracellular domain , a 21aa transmembrane segment and a 71aa cytoplasmic region. Following cleavage of the pre-and prosegments, it is expressed as a 240kD disulfide-linked homodimer. The extreme N-terminus aa1-16 of the mature molecule contains one threonine aa16 and three tyrosines aa5, 7, and 10 that are involved in ligand binding. The Thr residue allows for O-linked glycosylation in the form of a core-2 structure (GalNAc-Gal) linked in a B1,6 bond to a sialylated Lewisxmotif (GlcNAc linked to both Fuc and Gal with a terminal sialic acid residue). The three tyrosine residues allow for sulfation. When binding to P-selectin, Tyr sulfation and glycosylation are essential. Tyr7 provides the most efficient sulfate moiety, while Fuc and sialic acid are essentially mandatory. When binding to E- selectin, only carbohydrate is needed, while both carbohydrate and Tyr10 are used for L-selectin binding. There are 16 decameric aa repeats in the ECD of the longform of PSGL-1. This form is referred to as the A allele, and represents 65-80% of the population. Alleles B and C show deletions of decameric repeats 2 aa132-141 plus 9 and 10 aa222-241, respectively. Shorter forms may show weaker binding to P-selectin. Soluble forms of PSGL-1 are also known. Neutrophil elastase will cleave somewhere within repeats 5-9, while cathepsin G cleaves after Tyr7. The loss of Tyr5 and 7 should impact binding affinity. PSGL-1 is found on virtually all leukocytes and macrophages/DCs. Although there is similarity in the organization of the ECD between species, there is little aa identity. Human PSGL-1 ECD shares 51%, 52% and 43% aa sequence identity with equine, canine and mouse ECD. Applications: Suitable for use in Flow Cytometry. Other applications not tested. Recommended Dilution: Flow Cytometry: 2.5ug labels10e6 Optimal dilutions to be determined by the researcher. Storage and Stability: Lyophilized powder may be stored at -20C. Stable for 12 months at -20C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20C. Reconstituted product is stable for 12 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
