CEACAM 6, Recombinant, Human (Carcinoembryonic Antigen Related Cell Adhesion Molecule)

Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM-6), previously called nonspecific crossreacting antigen (NCA) or CD66c, is one of seven human CEACAM family members within the immunoglobulin superfamily (1-4). In humans, CEACAMs include type I transmembrane proteins (CEACAM-1, -3, and -4) and GPI-linked molecules (CEACAM-5 through -8) (1). There is no human CEACAM-2. Human CEACAM-6 is a 90 kD, GPI-linked membrane protein that contains a 34 amino acid (aa) signal sequence, a 286 aa extracellular domain (ECD), and a 24 aa hydrophobic C-terminal propeptide. The GPI membrane anchor is attached at the C terminus following cleavage of the propeptide. CEACAM-6 contains one N-terminal V-type Ig-like domain (N domain), followed by two C2-type Ig-like domains (2-4). It shows considerable glycosylation, including (sialyl) Lewis X , which mediates binding to E-selectin, galectins and some bacterial fimbrae (1, 2). Mature human CEACAM-6 shows 84%, 85%, 80%, 87% and 51% aa identity to the equivalent extracellular regions of human CEACAMs 1, 5 (CEA) and 8, rhesus CEACAM-2, and bovine CEACAM-6, respectively. CEACAM-6 is expressed by granulocytes and their precursors. Activation enhances surface expression by mobilizing CEACAM-6 from storage in azurophilic granules (5, 6). It often shows aberrant expression in acute lymphocytic leukemias (10). CEACAM-6 is also expressed epithelia of various organs and is upregulated in pancreatic and colon adenocarcinomas and hyperplastic polyps (7, 8). Over-expression confers resistance to adhesion-related apoptosis (anoikis) in tumor cells (8, 9). CEACAM-6 is an intercellular adhesion molecule, forming both homotypic, and heterotypic bonds with CEACAM-1, -5 and -8 through interaction of the V-type Ig-like domains (11, 12). Cross-linking of neutrophil CEACAM-6 augments a vb3 and b2 integrin-mediated adhesion, apparently by src and caveolin-mediated inside-out integrin activation (8, 13, 14). \n\nSource: \nHuman CD33 Signal Peptide (Met 1-Ala 16) Human CEACAM-6 (Lys 35-Gly 320) HHHHHH. A DNA sequence encoding the mature human CEACAM-6 (Lys 35-Gly 320; Accession # P40199) (Barnett, T. et al., 1998, Genomics 3(1):59) was fused to the signal peptide from human CD33 at the amino terminus and to a polyhistidine tag at the carboxy-terminus. The chimeric protein was expressed in a mouse myeloma cell line, NS0. \n\nMolecular Mass: \nBased on N-terminal sequencing, the recombinant human CEACAM-6 starts at Lys 35 and has a calculated molecular mass of approximately 32.0kD. As a result of glycosylation, the recombinant protein migrates as an approximately 57-75kD protein in SDS-PAGE under reducing conditions. \n\nEndotoxin Level: \n(same/less than) 1 EU/ug of the protein as determined by the LAL method.\n\nActivity: \nMeasured by the ability of the immobilized protein to support the adhesion of 1 microM calcium ionosphere treated human neutrophils. When 2x10e5 cells/well are added to CEACAM-6-coated plates (10ug/ml, 100ul/well), 35-60% of the cells will adhere after 20 minutes at 37 degrees C. \n\nReconstitution:\nIt is recommended that sterile PBS be added to the vial to prepare a working stock solution of no less than 100ug/ml. The carrier-free protein should be used immediately upon reconstitution to avoid losses in activity due to non-specific binding to the inside surface of the vial. For long term storage as a dilute solution, a carrier protein (e.g. 0.1% HSA or BSA) should be added to the vial. \n\nStorage:\nLyophilized samples are stable for up to twelve months at -20 degrees C. Upon reconstitution, this protein, in the presence of a carrier protein, can be stored under sterile conditions at 2-8 degrees C for one month or at -20 degrees C in a manual defrost freezer for three months without detectable loss of activity. Avoid repeated freeze-thaw cycles.

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SPECIFICATIONS

Catalog Number

C2589-79C

Size

50ug

Form

Supplied as a lyophilized powder from a 0.2um filtered solution in PBS.

Purity

(same/more than) 95%, as determined by SDS-PAGE and visualized by silver stain.

References

1. Beauchemin, N. et al., 1999, Exp. Cell Res. 252:243. \n2. Skubitz, K.M. et al., 1999, J. Biol. Regul. Homeost. Agents 13:244. \n3. Barnett, T. et al., 1988, Genomics 3:59. \n4. Tawaragi, Y. et al., 1988, Biochem. Biophys. Res. Comm. 150:89. \n5. Kuroki, M. et al., 1995, Immunol. Invest. 24:829. \n6. Ducker, T.P. and K.M. Skubitz, 1992, J. Leukoc. Biol. 52:11. \n7. Scholzel, S. et al., 2000, Am. J. Pathol. 156:595. \n8. Duxbury, M.S. et al., 2004, J. Biol. Chem. 279:23176. \n9. Ilantzis, C. et al., 2002, Neoplasia 4:151. \n10. Kalina, T. et al., 2005, BMC Cancer 5:38. \n11. Oikawa, S. et al., 1992, Biochem. Biophys. Res. Commun. 186:881. \n12. Kuroki, M. et al., 2001, J. Leukoc. Biol. 70:543. \n13. Duxbury, M.S. et al., 2004, Biochem. Biophys. Res. Comm. 317:133. \n14. Skubitz, K.M. et al., 1999, J. Leukoc. Biol. 60:106.