CTLA4 Human, IgG-His, Active
CTLA4, ALPS5, CD, CD152, CELIAC3, CTLA-4, GRD4, GSE, IDDM12, CD152, Cytotoxic T-Lymphocyte Associated Antigen-4, igG-His Tag.
Greater than 95.0% as determined by SDS-PAGE.
Description
CTLA4 Human produced in Sf9 Baculovirus cells is a single, glycosylated polypeptide chain containing 368 amino acids (36-161aa) and having a molecular mass of 40.8kDa.
CTLA4 is fused to a 242 amino acid hIgG-His-Tag at C-terminus and purified by proprietary chromatographic techniques.
Product Specs
Cytotoxic T-lymphocyte-associated protein 4 (CTLA4), also known as CD152, is an immune checkpoint receptor that suppresses immune responses. Primarily found on regulatory T cells, CTLA4 is also upregulated on activated conventional T cells, particularly in cancer, where it acts as an immune suppressor. CTLA4 binds to CD80 or CD86 on antigen-presenting cells, dampening T cell activation.
Recombinant human CTLA4, expressed in Sf9 insect cells using a baculovirus expression system, is a single, glycosylated polypeptide chain. This protein consists of 368 amino acids (residues 36-161), resulting in a molecular weight of 40.8 kDa. For purification and detection purposes, a 242 amino acid hIgG-His tag is fused to the C-terminus of CTLA4.
This CTLA4 solution is provided at a concentration of 0.5 mg/ml in a buffer consisting of 10% glycerol and phosphate-buffered saline (pH 7.4).
For short-term storage (2-4 weeks), the product can be stored at 4°C. For extended storage, it is recommended to store the protein at -20°C. To further enhance long-term stability, the addition of a carrier protein such as HSA or BSA (0.1%) is advised. It is crucial to avoid repeated freeze-thaw cycles to maintain protein integrity.
The purity of this protein is greater than 95%, as assessed by SDS-PAGE analysis.
The biological activity of this CTLA4 protein was evaluated through an IL-2 ELISA assay using Jurkat human acute T cell leukemia cells. The ED50, a measure of the protein's potency, was determined to be in the range of ≤ 150 ng/ml when co-stimulated with human B7 1/CD80.
CTLA4, ALPS5, CD, CD152, CELIAC3, CTLA-4, GRD4, GSE, IDDM12, CD152, Cytotoxic T-Lymphocyte Associated Antigen-4, igG-His Tag.
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NELTFLDDSI CTGTSSGNQV NLTIQGLRAM DTGLYICKVE LMYPPPYYLG IGNGTQIYVI
DPEPCPDSDL EPKSCDKTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN
KALPAPIEKT ISKAKGQPRE PQVYTLPPSR DELTKNQVSL TCLVKGFYPS DIAVEWESNG
QPENNYKTTP PVLDSDGSFF LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GKHHHHHH
Product Science Overview
CTLA4 is structurally similar to the T-cell co-stimulatory protein CD28, and both proteins bind to the same ligands, CD80 and CD86, on antigen-presenting cells . However, while CD28 sends stimulatory signals to T cells, CTLA4 transmits inhibitory signals, effectively acting as an “off switch” for T-cell activation .
The recombinant human CTLA4 protein with an IgG-His tag is typically expressed in HEK 293 cells and is purified to a high degree, often exceeding 95% purity . The His tag at the C-terminus facilitates purification and detection of the protein .
CTLA4 plays a critical role in maintaining immune homeostasis and preventing autoimmunity. By binding to CD80 and CD86 with higher affinity than CD28, CTLA4 competes with CD28 for these ligands, thereby inhibiting T-cell activation and proliferation . This mechanism is essential for preventing overactive immune responses that could lead to tissue damage.
In therapeutic contexts, recombinant CTLA4 proteins are used to modulate immune responses. For example, Abatacept (trade name Orencia) is a therapeutic fusion protein that combines the extracellular domain of CTLA4 with the Fc region of IgG1. It is used to treat autoimmune diseases by inhibiting T-cell activation .
Recombinant CTLA4 proteins are widely used in research to study T-cell regulation and immune checkpoint pathways. They are employed in various assays, including SDS-PAGE, ELISA, and functional assays to measure their binding ability and biological activity . These proteins are also valuable tools in drug development and immunotherapy research.
