IMP-477

CTLA4

Recombinant Human CTLA4 (NP_005205.2)(Met 1-Phe 162) was expressed in HEK293, fused with the C-terminal polyhistidine-tagged Fc region of Human IgG1 at the C-terminus.

Cytotoxic T-lymphocyte protein 4, also known as CTLA4 and CD152, is a single-pass type I membrane protein and a member of the immunoglobulin superfamily. It is the second member of the CD28 receptor family. The ligands or counterreceptors for these two proteins are the B7 family members, CD80 (B7-1) and CD86 (B7-2). CTLA4 transmits an inhibitory signal to T cells, whereas CD28 transmits a stimulatory signal. Intracellular CTLA4 is also found in regulatory T cells and may play an important role in their functions. CD152 or cytotoxic T lymphocyte antigen-4 (CTLA-4) is an essential receptor involved in the negative regulation of T cell activation. Because of its profound inhibitory role, CD152 has been considered a sound susceptible candidate in autoimmunity and a persuasive target for cancer immunotherapy. In particular, recent evidence suggests that CD152 is also important in the homeostasis and function of a population of suppressive cells, termed regulatory T cells (Treg).

HEK293

Human

C-His-hFc Tag

Lys 36

Lyophilized from sterile PBS, pH 7.4. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween80 are added as protectants before lyophilization.

The recombinant human CTLA4/Fc is a disulfide-linked homodimer. The reduced monomer consists of 375 amino acids and has a predicted molecular mass of 41.8 kDa. As a result of glycosylation, the apparent molecular mass of rh CTLA4/Fc monomer is approximately 50-55 kDa in SDS-PAGE under reducing conditions.

Met1-Phe162

< 1.0 EU per μg of the protein as determined by the LAL method

> 92 % as determined by SDS-PAGE

Samples are stable for up to twelve months from date of receipt at -20°C to -80°C. Store it under sterile conditions at -20°C to -80°C. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.

It is recommended that sterile water be added to the vial to prepare a stock solution of 0.2 ug/ul. Centrifuge the vial at 4°C before opening to recover the entire contents.