Glypican 5 (Glypiated Proteoglycan 5) (Carboxyfluorescein)

The glypicans (glypiated proteoglycans) are a small multigene family of GPI-linked proteoglycans that likely play a key role in embryonic morphogenesis (1-4). There are currently six known mammalian glypicans. They all share a common-sized protein core of 60-70 kD, an N-terminus which likely forms a compact globular domain, 14 conserved cysteines that form multiple intrachain disulfide bonds, and a number of C-terminal N- and O-linked carbohydrate attachment sites. Based on exon organization and the location of O-linked glycosylation sites, at least two subfamilies of glypicans are known, with one subfamily containing Glypicans 1, 2, 4, and 6, and another subfamily containing Glypican 3 and 5 (3, 5). Human Glypican 5 (GPC 5) is synthesized as a 572 amino acid (aa) preproprecursor that contains a 24 aa signal sequence, a 532 aa mature region and a 16 aa C-terminal pro-segment (6, 7). There are three potential N-linked, and five potential O-linked sites for glycosylation or glycanation. GPC 5 is believed to contain 6-7 kD of glycosylation and at least 55 kD of proteoglycan. This is based on an assumption of the presence of one heparan sulfate chain of 36 kD and one chrondroitin sulfate chain of 17 kD (7, 8). When added to the core molecular weight of 59 kD, the mature protein is approximately 120 kD in size. To date, however, the actual size of native human GPC 5 has not been reported and the suggestion of a chrondroitin sulfate modification is based on the expression of human GPC 5 in COS-7 cells (7). Human to mouse, there is 88% aa identity over the mature region. Cells known to express GPC 5 are principally embryonic in nature, and include neurons and mesenchyme (1, 7). The function of GPC 5 is essentially unknown. As a glypican family member, it may facilitate heparin-binding growth factor signaling and polyamine uptake into expressing cells (9, 10). Applications: Suitable for use in Flow Cytometry. Other applications not tested. Recommended Dilution: Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4 degrees C for short-term only. For long-term storage and to avoid repeated freezing and thawing, add sterile glycerol (40-50%), aliquot and store at -20 degrees C. Aliquots are stable for at least 6 months at -20 degrees C. 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.