Recombinant Human CTLA-4 Fc Chimera Avi-tag Protein, CF

Catalog #: AVI7268 Datasheet / COA / SDS

Biotinylated

Catalog #	Availability	Size / Price	Qty
AVI7268-050

Recombinant Human CTLA-4 Fc Chimera Avi-tag Protein Binding Activity

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Summary Product Datasheets Carrier Free Data Images Reconstitution Calculator Background Related Research Areas

Recombinant Human CTLA-4 Fc Chimera Avi-tag Protein, CF Summary

Learn more about Avi-tag Biotinylated Proteins

Why choose R&D Systems Avi-tag CTLA-4 Protein?

Guaranteed Bioactivity and High Purity: Bioactivity tested by functional ELISA and purity determined by SDS-PAGE to be greater than 95%.
Lot-to-Lot Consistency: Stringent QC testing performed on each lot to ensure consistent activity and purity.
Bulk Quantities Available: Bulk up and save with large mass quantities to meet your research needs. Supply agreements available, partner with us. Please contact us.
Most Respected, Most Cited Brand in Proteins: With over 35 years of providing the best recombinant proteins to the scientific community, R&D Systems continues to lead the industry in quality, activity, and purity.

Product Specifications

Purity

>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

Endotoxin Level

<0.10 EU per 1 μg of the protein by the LAL method.

Activity

Measured by its binding ability in a functional ELISA. When Recombinant Human B7‑1/CD80Fc Chimera (Catalog # 10133-B1) is immobilized at 0.5 µg/mL (100 µL/well), Biotinylated Recombinant Human CTLA-4 Fc Chimera Avi-tag (Catalog # AVI7268) binds with an ED₅₀ of 0.4-2.4 ng/mL.

Source

Human embryonic kidney cell, HEK293-derived human CTLA-4 protein

Human CTLA-4 (Ala37-Phe162) Accession # P16410.3	IEGRMD	Human IgG₁ (Pro100-Lys330)	Avi-tag
N-terminus			C-terminus

Accession #

P16410.3

N-terminal Sequence
Analysis

Ala37

Structure / Form

Disulfide-linked homodimer, biotinylated via Avi-tag

Predicted Molecular Mass

42 kDa

SDS-PAGE

53-61 kDa, under reducing conditions

Product Datasheets

AVI7268

Product Datasheet

COA

SDS

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

AVI7268

Formulation	Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
Reconstitution	Reconstitute at 500 μg/mL in PBS.
Shipping	The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage:	Use a manual defrost freezer and avoid repeated freeze-thaw cycles. 12 months from date of receipt, -20 to -70 °C as supplied. 1 month, 2 to 8 °C under sterile conditions after reconstitution. 3 months, -20 to -70 °C under sterile conditions after reconstitution.

Scientific Data

Binding Activity

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When Recombinant Human B7-1/CD80 Fc Chimera (Catalog # 10133-B1) is immobilized at 0.5 µg/mL, Biotinylated Recombinant Human CTLA-4 Fc Chimera Avi-tag (Catalog # AVI7268) binds with an ED₅₀ of 0.4-2.4 ng/mL.

SDS-PAGE

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2 μg/lane of Biotinylated Recombinant Human CTLA-4 Fc Chimera Avi-tag (Catalog # AVI7268) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 53-61 kDa and 110-120 kDa, respectively.

Surface Plasmon Resonance (SPR)

Surface plasmon resonance sensorgram of Avi-tag biotinylated human CTLA-4 protein binding to human B7-1/CD80

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Avi-tag Biotinylated Recombinant Human CTLA-4 Fc protein (Catalog # AVI7268) was immobilized on a Biacore Sensor Chip CM5 via the Avi-tag biotin, and binding to Recombinant Human B7-1/CD80 Fc protein (10133-B1) was measured at a concentration range between 82 pM and 21 nM. The double-referenced sensorgram was fit to a 1:1 binding model to determine the binding kinetics and affinity, with an affinity constant of KD=0.2511 nM.

Reconstitution Calculator

Background: CTLA-4

CTLA-4 (cytotoxic T-lymphocyte associated protein‑4, designated CD152), is a type I transmembrane T cell inhibitory molecule that is a member of the Ig superfamily (1, 2). Human or mouse CTLA-4 cDNA encodes 223 amino acids (aa) including a 35 aa signal sequence, a 126 aa extracellular domain (ECD) with one Ig-like V-type domain, a 21 aa transmembrane (TM) sequence, and a 41 aa cytoplasmic sequence. It is found as a covalent homodimer of 41-43 kDa (2) Within the ECD, human CTLA-4 shares 68%, 71% and 83‑86% aa sequence identity with mouse, rat and porcine/bovine/rabbit/feline/canine CTLA-4, respectively. A 174 aa form that lacks TM and cytoplasmic sequences (sCTLA-4) is possibly secreted (3-5). Isoforms of 56-79 aa that mainly contain parts of the cytoplasmic domain are reported. In mouse, an isoform lacking the Ig-like domain has ligand-independent inhibitory activity and is termed liCTLA-4 (6). CD28, which is structurally related to CTLA-4, is constitutively expressed on naïve T cells and promotes T cell activation when engaged by B7-2 on antigen-presenting cells (APC) within the immunological synapse (IS) (1, 7, 8). In contrast, CTLA-4 is recruited from intracellular vesicles to the IS beginning 1-2 days after T cell activation (2, 7, 8). It forms a linear lattice with B7-1 on APC, inducing negative regulatory signals and ending T cell activation (9). Abatacept, a therapeutic human CTLA-4-Ig fusion protein (trade name Orencia), competes with CD28 for B7-1 and B7-2 binding and has been used to antagonize T cell activation in autoimmune conditions and to enhance transplant survival (10). Mice deleted for CTLA-4 show no abnormalities until after birth, but then develop lethal autoimmune reactions due to continued T cell activation and poor control by regulatory T cells, which constitutively express CTLA-4 in wild-type mice and humans (11-13).

References

Harper, K. et al. (1991) J. Immunol. 147:1037.
Teft, W.A. et al. (2006) Annu. Rev. Immunol. 24:65.
Magistrelli, G. et al. (1999) Eur. J. Immunol. 29:3596.
Tector, M. et al. (2009) BMC Immunol. 10:51.
Oaks, M.K. and K.M. Hallett (2000) J. Immunol. 164:5015.
Vijayakrishnan, L. et al. (2004) Immunity 20:563.
Pentcheva-Hoang, T. et al. (2004) Immunity 21:401.
Jansson, A. et al. (2005) J. Immunol 175:1575.
Darlington, P.J. et al. (2005) J. Immunol. 175:996.
Platt, A.M. et al. (2010) J. Immunol. 185:1558.
Wing, K. et al. (2008) Science 322:271.
Friedline, R.H. et al. (2009) J. Exp. Med. 206:421.
Jain, N. et al. (2010) Proc. Natl. Acad. Sci. USA 107:1524.

Long Name

Cytotoxic T-lymphocyte-associated Molecule 4

Entrez Gene IDs

1493 (Human); 12477 (Mouse); 403696 (Canine); 102115124 (Cynomolgus Monkey)

Alternate Names

CD; CD152 antigen; CD152; CD152IDDM12; CD28; celiac disease 3; CELIAC3; CTLA4; CTLA-4; cytotoxic T-lymphocyte antigen 4; cytotoxic T-lymphocyte protein 4; Cytotoxic T-lymphocyte-associated antigen 4; cytotoxic T-lymphocyte-associated protein 4; cytotoxic T-lymphocyte-associated serine esterase-4; GRD4; GSE; ICOS; ligand and transmembrane spliced cytotoxic T lymphocyte associated antigen 4