CD19 is a single-pass type I membrane protein containing 2 Ig-like C2-type (immunoglobulin-like) domains. CD19 is expressed on follicular dendritic cells and B cells. In fact; it is present on B cells from earliest recognizable B-lineage cells during development to B-cell blasts but is lost on maturation to plasma cells. CD19 primarily acts as a B cell co-receptor in conjunction with CD21 and CD81. Upon activation; the cytoplasmic tail of CD19 becomes phosphorylated; which leads to binding by Src-family kinases and recruitment of PI-3 kinase. CD19 Assembles with the antigen receptor of B lymphocytes in order to decrease the threshold for antigen receptor-dependent stimulation. Defects in CD19 are the cause of immunodeficiency common variable type 3 (CVID3) which is a primary immunodeficiency characterized by antibody deficiency; hypogammaglobulinemia; recurrent bacterial infections and an inability to mount an antibody response to antigen.
Immobilized Human FMC63 at 2µg/ml(100 ?l/well) can bind Human CD19-Fc. The ED50 of Human CD19-Fc is 2.48 ug/ml .
Endotoxin:
<1.0 EU per µg as determined by the LAL method.
Protein Construction:
Recombinant Human CD19 is produced by our Mammalian expression system and the target gene encoding Pro20-Lys291 is expressed with a Fc tag at the C-terminus.
Purity:
> 80 % as determined by reducing SDS-PAGE.
Mol Mass:
57.3 kDa
AP Mol Mass:
78 kDa
Formulation:
Lyophilized from a 0.2 µm filtered solution of 20mM PB;150mM NaCl;1%BSA;0.05%NaN3;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.
