CEACAM8, also known as CD66b or NCA-95, is a single chain, GPI-anchored, highly glycosylated protein belonging to the carcinoembryonic antigen family. There are four members in this family: CD66a, CD66b, CD66c, and CD66d. Members of CEACAM family are widely expressed especially on human neutrophils, and, depending on the tissue, capable of regulating diverse functions including tumor promotion, tumor suppression, angiogenesis, and neutrophil activation. Abnormal overexpression and downregulation of some CEACAMs have been described in tumor cells. Monoclonal antibodies grouped in the CD66 cluster recognize CEACAM members. Ectopic CD66 expression is commonly detected in B-cell lineage acute lymphoblastic leukemia (ALL). CEACAM8(CD66b) is also an activation marker for human granulocytes. However, its biological functions are largely unknown in eosinophils. It has been reported that CD66b is highly expressed on the surface of human peripheral blood eosinophils isolated from healthy individuals. Engagement of CD66b by mAb or a natural ligand, galectin-3, activated a Src kinase family molecule, hemopoietic cell kinase (Hck), and induced cellular adhesion, superoxide production, and degranulation of eosinophils. CD66b molecules were localized in lipid rafts, and disruption of lipid rafts or removal of the GPI anchor inhibited the adhesion and activation of eosinophils. Importantly, CD66b was constitutively and physically associated with a beta2 integrin, CD11b, and cross-linking of CD66b induced a striking clustering of CD11b molecules. Thus, CD66b molecules are involved in regulating adhesion and activation of eosinophils, possibly through their localization in lipid rafts and interaction with other cell surface molecules, such as CD11b. Binding of exogenous or endogenous carbohydrate ligands(s) to CD66b may be important in the release of proinflammatory mediators by human eosinophils.
Product Name:
Human CEACAM8/CD66b Recombinant Protein (RPES0231)
Measured by its binding ability in a functional ELISA. Immobilized human CEACAM6-his at 10 µg/mL (100 ?l/well) can bind biotinylated human CEACAM8-his, The EC50 of biotinylated human CEACAM8-his is 0.17 µg/mL.
Endotoxin:
<1.0 EU per µg as determined by the LAL method.
Protein Construction:
A DNA sequence encoding the human CEACAM8 (NP_001807.2) without the pro peptide (Met 1-Ser319) was expressed, with a polyhistidine tag at the C-terminus.
Purity:
> 96 % as determined by reducing SDS-PAGE.
Mol Mass:
32.8 kDa
AP Mol Mass:
55-60 kDa
Formulation:
Lyophilized from sterile PBS, pH 7.4
Shipping:
This product is provided as lyophilized powder which is shipped with ice packs.
Stability and Storage:
Lyophilized proteins are stable for up to 12 months when stored at -20 to -80°C. Reconstituted protein solution can be stored at 4-8°C for 2-7 days. Aliquots of reconstituted samples are stable at < -20°C for 3 months.
