Synonym

CD19,B4,CVID3,MGC12802

Source

Biotinylated Human CD19, Fc Tag (CD9-H8259) is expressed from human HEK293 cells. It contains AA Pro 20 - Lys 291 (Accession # AAH06338). It is the biotinylated form of Human CD19 Protein, Fc Tag (Cat # CD9-H5259). Predcited N-terminus: Pro 20

Molecular Characterization

This protein carries a human IgG1 Fc fragment at the C-terminus.

The protein has a calculated MW of 56.3 kDa. The protein migrates as 56-66 kDa on a SDS-PAGE gel under reducing (R) condition due to glycosylation.

Biotinylation

The primary amines in the side chains of lysine residues and the N-terminus of the protein are conjugated with biotins using standard chemical labeling method. A standard biotin reagent (13.5 angstroms) is used in this product.

Biotin:Protein Ratio

The biotin to protein ratio is 2.5-3.5 as determined by the HABA assay.

Endotoxin

Less than 1.0 EU per μg by the LAL method.

Purity

>95% as determined by SDS-PAGE.

Formulation

Lyophilized from 0.22µm filtered solution in PBS (pH 7.4) with Trehalose as protectant.

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Reconstitution

Reconstitute at 100 μg/mL in sterile deionized water. For best performance, we strongly recommend you to follow the reconstitution protocol provided in the COA.

Storage

For long term storage, the product should be stored at lyophilized state at -20°C or lower. Please avoid repeated freeze-thaw cycles.

No activity loss is observed after storage at:

SDS-PAGE

Biotinylated Human CD19, Fc tag on SDS-PAGE under reducing (R) condition. The gel was stained overnight with Coomassie Blue. The purity of the protein is greater than 95%.

Bioactivity

Immobilized FMC63 mAb at 2 μg/mL (100 μL/well) can bind Biotinylated Human CD19, Fc tag (Cat# CD9-H8259) with a linear range of 0.15-2.5 μg/mL.

Background

B-lymphocyte antigen CD19, is a single-pass type I membrane protein which contains two Ig-like C2-type (immunoglobulin-like) domains. CD19 is expressed on follicular dendritic cells and B cells. Upon activation, the cytoplasmic tail of CD19 becomes phosphorylated, which leads to binding by Src-family kinases and recruitment of PI-3 kinase. As on T cells, several surface molecules form the antigen receptor and form a complex on B lymphocytes. The (almost) B cell-specific CD19 phosphoglycoprotein is one of these molecules. The others are CD21 and CD81. These surface immunoglobulin (sIg)-associated molecules facilitate signal transduction. On living B cells, anti-immunoglobulin antibody mimicking exogenous antigen causes CD19 to bind to sIg and internalize with it. The reverse process has not been demonstrated, suggesting that formation of this receptor complex is antigen-induced. This molecular association has been confirmed by chemical studies. Mutations in CD19 are associated with severe immunodeficiency syndromes characterized by diminished antibody production. CD19 has been shown to interact with: CD81, CD82, Complement receptor 2, and VAV2.

References

• (1) Pesando JM, et al., J. Exp. Med. 170 (6): 2159–64.
• (2) van Zelm MC, et al., 2006, N. Engl. J. Med. 354 (18): 1901–12.
• (3) Bradbury LE, et al., 1992, J. Immunol. 149 (9): 2841–50.
• (4) Horváth G, et al., 1998, J. Biol. Chem. 273 (46): 30537–43.
• (5) Imai T, et al., 1995, J. Immunol. 155 (3): 1229–39.
• (6) Doody GM, et al., 2000, EMBO J. 19 (22): 6173–84.

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