Purity
>95%, by SDS-PAGE with silver staining
Endotoxin Level
<0.10 EU per 1 μg of the protein by the LAL method.
Activity
Measured by its binding ability in a functional ELISA. Recombinant Mouse CD42b/GPIb alpha is immobilized at 0.5 μg/mL (100 μL/well), the concentration of Recombinant Human vWF‑A2 (Catalog # ) that produces 50% optimal binding response is approximately 0.1-0.5 μg/mL in the presence of ristocetin.
Source
Chinese Hamster Ovary cell line, CHO-derived Gln17-Pro612, with a C-terminal 6-His tag Accession # O35930
Accession #
N-terminal Sequence
AnalysisNo results obtained: Gln17 inferred from enzymatic pyroglutamate treatment revealing His18
Predicted Molecular Mass
66 kDa
SDS-PAGE
108-150 kDa, reducing conditions
8428-GP |
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Formulation Lyophilized from a 0.2 μm filtered solution in PBS. | ||
Reconstitution Reconstitute at 500 μg/mL in sterile PBS. | ||
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. | ||
Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
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Background: CD42b/GPIb alpha
Platelet glycoprotein Ib alpha chain (GPIb alpha ), also known as CD42b, is a 145 kDa type I transmembrane member of the leucine-rich repeat (LRR) family of ligand binding proteins (1-3). Mature mouse GPIb alpha contains a 596 amino acid (aa) extracellular domain (ECD), a 21 aa transmembrane domain, and a 101 aa cytoplasmic region. The ECD of mouse GPIb alpha shares 48% and 51% aa sequence identity with human and rat GPIb alpha respectively. GPIb alpha is expressed by platelets and functions as the ligand-binding component of the platelet GPIb-IX-V complex (4). LRR2 and 4 of the extracellular domain (ECD) of GPIb alpha will trigger von Willebrand factor (vWF)-dependent adhesion of platelets to the vascular endothelium under high shear stress conditions (5, 6). Furthermore, the C-terminal anionic flanking region of the LRRs contains three tyrosine residues that are post-translationally sulfated. This modification is essential for GPIb alpha binding to vWF and Thrombin (7). The C-terminal anionic region also contains a sialomucin domain with N- and O-linked carbohydrates, and two cysteines near the membrane that allow dimerization with GP1b beta (1-6). Four additional human isoforms are generated with 1-4 repeats of aa 398-411 within the sialomucin domain of mature GPIb alpha (8). The metalloproteinase TACE/ADAM17 constitutively and inducibly cleaves GPIb alpha and releases a soluble circulating form called Glycocalicin (9, 10). GPIb alpha binding to ligands such as Thrombin, Kininogen, and Coagulation Factors XI and XII helps to initiate platelet activation and coordinate the coagulation cascade (1, 11-13). Binding to vWF or Thrombospondin in the plasma or matrix, vWF or P-Selectin on endothelial cells, or the Integrin alpha M beta 2 (MAC-1) on myeloid cells, controls responses to vascular injury (1, 14). Bernard-Soulier syndrome and platelet-type von Willebrand disease are platelet function disorders that can be caused by mutations in GPIb alpha (1, 15).
References:
Andrews, R.K. et al. (2007) Arterioscler. Thromb. Vasc. Biol. 27:1511.
Lopez, J.A. et al. (1987) Proc. Natl. Acad. Sci. USA 84:5615.
Wenger, R.H. et al. (1988) Biochem. Biophys. Res. Commun. 156:389.
Luo, S-Z. et al. (2007) Blood 109:603.
Uff, S. et al. (2002) J. Biol. Chem. 277:35657.
Shen, Y. et al. (2006) J. Biol. Chem. 281:26419.
Dong, J. et al. (2001) J. Biol. Chem. 276:16690.
Ishida, F. et al. (1995) Blood 86:1356.
Gardiner, E.E. et al. (2007) J. Thromb. Haemost. 5:1530.
Beer, J.H. et al. (1994) Blood 83:691.
Adam, F. et al. (2003) Eur. J. Biochem. 270:2959.
Baglia, F.A. et al. (2004) J. Biol. Chem. 279:49323.
Bradford, H.N. et al. (2000) J. Biol. Chem. 275:22756.
Wang, Y. et al. (2005) Circulation 112:2993.
Othman, M. et al. (2005) Blood 105:4330.
Long Name:
Glycoprotein lb [Platelet] alpha
Entrez Gene IDs:
2811 (Human); 14723 (Mouse)
Alternate Names:
Antigen CD42b-alpha; BP1BA; BSS; CD42b antigen; CD42b; CD42b-alpha; glycoprotein Ib (platelet), alpha polypeptide; Glycoprotein Ibalpha; GP1B; GP1BA; GPIb alpha; GP-Ib alpha; GPIbA; GPIb-alpha; MGC34595; platelet glycoprotein Ib alpha chain; platelet membrane glycoprotein 1b-alpha subunit
