Recombinant Biotinylated Human CTLA-4, Fc Tag, Avi Tag (Avitag™), 25µg

Background
CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4) is also known as CD152 (Cluster of differentiation 152), is a protein receptor that downregulates the immune system. CTLA4 is a member of the immunoglobulin superfamily, which is expressed on the surface of Helper T cells and transmits an inhibitory signal to T cells. The protein contains an extracellular V domain, a transmembrane domain, and a cytoplasmic tail. Alternate splice variants, encoding different isoforms. CTLA4 is similar to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and B7-2 respectively, on antigen-presenting cells. 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 be important to their function. Fusion proteins of CTLA4 and antibodies (CTLA4-Ig) have been used in clinical trials for rheumatoid arthritis.

Source
Recombinant Biotinylated Human CTLA-4, Fc,Avitag (CT4-H82F3) is expressed from human 293 cells (HEK293). It contains AA Ala 37 - Phe 162 (Accession # P16410-1).
Predicted N-terminus: Ala 37

Molecular Characterization
This protein carries a human IgG1 Fc tag at the C-terminus, followed by a Avi tag (Avitag™).
The protein has a calculated MW of 41.8 kDa. The protein migrates as 48-60 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

Biotinylation
Biotinylation of this product is performed using Avitag™ technology. Briefly, the single lysine residue in the Avitag is enzymatically labeled with biotin.

Passed as determined by the HABA assay / binding ELISA.

Endotoxin
Less than 1.0 EU per μg by the LAL method.

Purity
>95% as determined by SDS-PAGE.

Formulation
Lyophilized from 0.22 μm filtered solution in Tris with Glycine, Arginine and NaCl, pH7.5. Normally trehalose is added as protectant before lyophilization.

Reconstitution
Please see Certificate of Analysis for specific instructions.
For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

Bioactivity
Please refer to product data sheet.

Storage
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please avoid repeated freeze-thaw cycles.
This product is stable after storage at:
-20°C to -70°C for 12 months in lyophilized state;
-70^°C for 3 months under sterile conditions after reconstitution.

Clinical and Translational Updates

(1) "Ultrasound-targeted microbubble destruction remodels tumour microenvironment to improve immunotherapeutic effect"
Liu, Zhang, Liu et al
Br J Cancer (2022)
(2) "New insight into GARP striking role in cancer progression: application for cancer therapy"
Lahimchi, Eslami, Yousefi
Med Oncol (2022) 40 (1), 33
(3) "Significance of regulatory T cells in cancer immunology and immunotherapy"
Sugiyama, Hinohara, Hiroyoshi
Exp Dermatol (2022)
Showing 1-3 of 12240 papers.

Citations

(1) "Revealing the atomistic details behind the binding of B7–1 to CD28 and CTLA-4: A comprehensive protein-protein modelling study"
Authors: G Aravindhan, et al.
Journal: BBA-GEN SUBJECTS 2018
Application: ELISA