CTLA4, also known as cytotoxic T-lymphocyte-associated protein 4, is a co-inhibitory molecule expressed on T cells that mediates the inhibition of T-cell function. This protein is a crucial immune regulator that mediates both negative costimulation signals to T cells, and regulatory T (Treg)-cell extrinsic control of effector responses. It has been implicated in several autoimmune diseases, such as systemic lupus erythematosus. Recombinant protein corresponding to aa36-161 from human CTLA4, fused to His-Tag at C-terminal, expressed in insect cell. Molecular Weight: ~14.6kD (135aa) 18-28KD (SDS-PAGE under reducing conditions.) Amino Acid Sequence: ADLKAMHVAQ PAVVLASSRG IASFVCEYAS PGKATEVRVT VLRQADSQVT EVCAATYMMG NELTFLDDSI CTGTSSGNQV NLTIQGLRAM DTGLYICKVE LMYPPPYYLG IGNGTQIYVI DPEPCPDSDH HHHHH Biological Activity: Determined by the IL-2 ELISA in a using Jurkat human acute T cell leukemia cells. The ED50 range <150ng/ml with Human B7-1/CD80. Endotoxin: <1EU/1ug (LAL) Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.