Recombinant Human LAG-3 Fc Chimera Biotinylated Protein, CF

When Recombinant Human LSECtin/CLEC4G (Catalog # 2947-CL) iscoated at 1 μg/mL, 100 μL/well,Biotinylated Recombinant Human LAG‑3 Fc Chimera Biotinylated (Catalog # BT2319) binds with an ED50of 0.2‑2 μg/mL.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human LAG-3 Fc Chimera Biotinylated Protein, CF Summary

• Details of Functionality: Measured by its binding ability in a functional ELISA. When Recombinant Human LSECtin/CLEC4G (Catalog # 2947-CL) is coated at 1 μg/mL, 100 uL/well, biotinylated recombinant LAG-3 Fc Chimera (Catalog# BT2319) binds with an ED₅₀ of 0.2-2 μg/mL.
• Source: Mouse myeloma cell line, NS0-derived human LAG-3 protein
  

  Human LAG-3 (Leu23-Leu450) Accession # P18627	IEGRMD	Human IgG1 (Pro100-Lys330)
  N-terminus		C-terminus

• Accession #: P18627
• N-terminal Sequence: Leu23
• Structure / Form: Disulfide-linked homodimer. Biotinylated via amines.
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 72.7 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 74-91 kDa, reducing conditions

Packaging, Storage & Formulations

• 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.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain.
• Reconstitution Instructions: Reconstitute at 200 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human LAG-3 Fc Chimera Biotinylated Protein, CF

• CD223 antigen
• CD223
• LAG3
• LAG-3
• lymphocyte activating 3
• lymphocyte activation gene 3 protein
• lymphocyte-activation gene 3
• Secreted lymphocyte activation gene 3 protein
• sLAG-3

Background

LAG-3 (Lymphocyte activation gene-3), designated CD223, is a 70 kDa type I transmembrane protein that is a member of the immunoglobulin superfamily (IgSF) (1, 2). LAG-3 shares approximately 20% amino acid sequence homology with CD4, but has similar structure and binds to MHC class II with higher affinity, providing negative regulation of T cell receptor signaling (1, 2). Human LAG-3 cDNA encodes 525 amino acids (aa) that include a 28 aa signal sequence, a 422 aa extracellular domain (ECD) with four Ig-like domains, a  transmembrane region and a highly charged cytoplasmic region. Within the ECD, human LAG-3 shares 70%, 67%, 76%, and 73% aa sequence identity with mouse, rat, porcine, and bovine LAG-3, respectively. LAG-3 is expressed on activated CD4⁺ and CD8⁺ T cells, NK cells, and plasmacytoid dendritic cells (pDC), but not on resting T cells (1-3). LAG-3 on activated CD4⁺CD25⁺ T_reg cells plays a role in their suppressive activity (4). LAG-3 limits the expansion of activated T cells and pDC in response to selected stimuli (3-5). A soluble 54 kDa form, sLAG-3, can be shed by metalloproteinases ADAM10 and TACE/ADAM17 (6, 7). While monomeric sLAG-3 itself may be inactive, shedding allows for normal T cell activation by removing negative regulation (7). Binding of a homodimerized sLAG-3/Ig fusion protein to MHC class II molecules induces maturation of immature DC, and secretion of cytokines such as IFN-gamma and TNF-alpha by type 1 cytotoxic CD8⁺ T cells and NK cells (8, 9). sLAG-3/Ig has been used as a potential adjuvant to stimulate a cytotoxic anti-cancer immune response (9, 10). In mice, deletion of LAG-3 and another negative regulator, PD-1, facilitates anti-cancer response but also blocks self-tolerance and increases susceptibility to autoimmune diseases (11, 12). In humans, antibody-mediated down‑regulation of LAG-3 and PD-1 allows more effective control of chronic malaria, while in NOD (non‑obese diabetic) mice, deletion of LAG-3 alone accelerates diabetes (12-14).

1. Triebel, F. et al. (1990) J. Exp. Med. 171:1393.
2. Baixeras, E. et al. (1992) J. Exp. Med 176:327.
3. Workman, C.J. et al. (2004) J. Immunol. 172:5450.
4. Huang, C.T. et al. (2004) Immunity 21:503.
5. Workman, C.J. et al. (2009) J. Immunol. 182:1885.
6. Li, N. et al. (2004) J. Immunol. 173:6806.
7. Li, N. et al. (2007) EMBO J. 26:494.
8. Andreae, S. et al. (2003) Blood 102:2130.
9. Brignone, C. et al. (2007) J. Immunol. 179:4202.
10. Brignone, C. et al. (2010) J. Transl. Med. 8:71.
11. Woo, S.R. et al. (2011) Cancer Res. 72:917.
12. Okazaki, T. et al. (2011) J. Exp. Med. 208:395.
13. Bettini, M. et al. (2011) J. Immunol. 187:3493.
14. Butler, N.S. et al. (2012) Nat. Immunol. 13:188.

Bioinformatics

• Uniprot:
  • P18627()