B-lymphocyte antigen CD19 (CD19), partial (Active), human, recombinant

Organism: Homo sapiens (Human). Source: Mammalian cell. Expression Region: 20-291aa. Protein Length: Extracellular Domain. Tag Info: C-terminal Fc-tagged. Target Protein Sequence: PEEPLVVKVE EGDNAVLQCL KGTSDGPTQQ LTWSRESPLK PFLKLSLGLP GLGIHMRPLA IWLFIFNVSQ QMGGFYLCQP GPPSEKAWQP GWTVNVEGSG ELFRWNVSDL GGLGCGLKNR SSEGPSSPSG KLMSPKLYVW AKDRPEIWEG EPPCLPPRDS LNQSLSQDLT MAPGSTLWLS CGVPPDSVSR GPLSWTHVHP KGPKSLLSLE LKDDRPARDM WVMETGLLLP RATAQDAGKY YCHRGNLTMS FHLEITARPV LWHWLLRTGG WK. Purity: Greater than 95% as determined by SDS-PAGE. Endotoxin: Less than 1.0 EU/µg as determined by LAL method. Biological Activity: Measured by its binding ability in a functional ELISA. Immobilized Human FMC63 at 2µg/ml can bind Human CD19-Fc, the ED50 of Recombinant Human CD19-Fc is 55.28 ng/ml. Form: Lyophilized powder. Buffer: Lyophilized from a 0.2 µm filtered 20 mM PB, 150mM NaCl, pH 7.4. Reconstitution: We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Please reconstitute protein in deionized sterile water to a concentration of 0.1-1.0 mg/mL.We recommend to add 5-50% of glycerol (final concentration) and aliquot for long-term storage at -20 °C/-80 °C. Our default final concentration of glycerol is 50%. Customers could use it as reference. Storage: The shelf life is related to many factors, storage state, buffer ingredients, storage temperature and the stability of the protein itself. Generally, the shelf life of liquid form is 6 months at -20 °C/-80 °C. The shelf life of lyophilized form is 12 months at -20 °C/-80 °C. Notes: Repeated freezing and thawing is not recommended. Store working aliquots at 4 °C for up to one week. Relevance: 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. Reference: n/a. Function: Assembles with the antigen receptor of B-lymphocytes in order to decrease the threshold for antigen receptor-dependent stimulation.