CD19 Protein, Human (Biotinylated, HEK293, Fc-Avi)

The CD19 protein is a B cell antigen receptor coreceptor that enhances downstream signaling pathways, lowers the activation threshold, and helps B cells respond to antigens. It activates phosphatidylinositol 3-kinase and mobilizes intracellular Ca(2+). CD19 Protein, Human (Biotinylated, HEK293, Fc) is the recombinant human-derived CD19 protein, expressed by HEK293 , with C-Avi, C-hFc labeled tag.

The CD19 Protein serves as a coreceptor for the B-cell antigen receptor complex (BCR) on B-lymphocytes, playing a pivotal role in decreasing the threshold for activation of downstream signaling pathways and facilitating B-cell responses to antigens. It activates signaling pathways leading to the activation of phosphatidylinositol 3-kinase and the mobilization of intracellular Ca(2+) stores. Although not required for early steps during B cell differentiation in the blood marrow, CD19 is essential for the normal differentiation of B-1 cells. Moreover, it is crucial for normal B cell differentiation and proliferation in response to antigen challenges, influencing serum immunoglobulin levels and the production of high-affinity antibodies in response to antigen challenge. CD19 forms complexes with CR2/CD21, CD81, and IFITM1/CD225 in the membrane of mature B-cells. It interacts directly with CD81, a crucial interaction for trafficking and compartmentalization of the CD19 receptor on the cell surface of activated B cells. Additionally, CD19 interacts with VAV, GRB2, SOS, PLCG2, LYN, and the regulatory p85 subunit of phosphatidylinositol 3-kinase when phosphorylated on specific tyrosine residues.

1.Measured by its binding ability in a functional ELISA. Immobilized Anti-CD19 antibody at 1 μg/mL can bind Biotinylated Human CD19. The EC ₅₀ is 44.90-68.72 ng/mL.
2.Measured by its binding ability in a functional ELISA. Immobilized Biotinylated Human CD19 on streptavidin precoated plate can bind Anti-CD19 antibody at 2 μg/mL (100 μL/well), the EC₅₀ is 2.775-5.036 ng/mL.
3.Measured by its binding ability in a functional ELISA. Immobilized Anti-CD19 antibody at 2 μg/mL can bind Recombinant Human B-lymphocyte antigen CD19, partial,Biotinylated, the EC₅₀ of human CD19 protein is 18.09 - 24.59 ng/ml.

Human

HEK293

C-Avi;C-hFc

P15391-1 (P20-K291)

930  [NCBI]

Extracellular Domain

Biotin

The single lysine residue in Avitag is biotinylated through an enzymatic reaction.

PEEPLVVKVEEGDNAVLQCLKGTSDGPTQQLTWSRESPLKPFLKLSLGLPGLGIHMRPLAIWLFIFNVSQQMGGFYLCQPGPPSEKAWQPGWTVNVEGSGELFRWNVSDLGGLGCGLKNRSSEGPSSPSGKLMSPKLYVWAKDRPEIWEGEPPCLPPRDSLNQSLSQDLTMAPGSTLWLSCGVPPDSVSRGPLSWTHVHPKGPKSLLSLELKDDRPARDMWVMETGLLLPRATAQDAGKYYCHRGNLTMSFHLEITARPVLWHWLLRTGGWK

Approximately 60-90 kDa, based on SDS-PAGE under reducing condition, due to the glycosylation.

≥ 95%, as determined by reducing SDS-PAGE.

Lyophilized powder.

Lyophilized a 0.22 μm filtered solution of PBS, 6% Trehalose, pH 7.4.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

Stored at -20°C for 2 years from date of receipt. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.