Recombinant Human LAIR1 Fc Chimera Protein, CF

When Bovine Collagen I is coated at 10 µg/mL, Recombinant HumanLAIR-1 Fc Chimera binds with an ED50 of25-150 ng/mL.

2 μg/lane of Recombinant Human LAIR1 was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® blue staining, showing bands at 55-65 kDa and 110-130 kDa, respectively.

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

Recombinant Human LAIR1 Fc Chimera Protein, CF Summary

• Details of Functionality: Measured by its binding ability in a functional ELISA. When Bovine Collagen I is coated at 10 µg/mL, 100 μL/well, Recombinant Human LAIR1 Fc Chimera binds with an ED₅₀ of 25-150 ng/mL.
• Source: Human embryonic kidney cell, HEK293-derived human LAIR1 protein
  

  Human LAIR1 (Gln22-His163) Accession # NP_002278	IEGRMD	Human IgG1 (Pro100-Lys330)
  N-terminus		C-terminus

• Accession #: NP_002278
• N-terminal Sequence: No results obtained. Gln22 inferred from enzymatic pyroglutamate treatment revealing Glu23.
• Structure / Form: Disulfide-linked homodimer
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 42 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: 55-65 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage:
  • 12 months from date of receipt, ≤ -20 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, ≤ -20 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 500 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 LAIR1 Fc Chimera Protein, CF

• CD305 antigen
• CD305
• CD305leukocyte-associated Ig-like receptor 1
• HLAIR1
• LAIR1
• LAIR-1
• leukocyte-associated immunoglobulin-like receptor 1

Background

LAIR1 (leukocyte-associated Ig-like receptor-1, designated CD305) is an approximately 40 kDa type I transmembrane inhibitory glycoprotein belonging to the Ig superfamily (1-4). LAIR1 is a collagen-binding protein that is expressed in a differentiation- and activation-dependent manner on most immune cells, including T, B, NK and dendritic cells (DC), monocytes, CD34⁺ hematopoietic progenitors, most thymocytes, and selected granulocyte populations (2-7). Mature human LAIR1 is a 266 amino acid (aa) type I transmembrane protein that includes a 144 aa extracellular domain (ECD) with one collagen-binding C2-type Ig-like domain, and a 101 aa cytoplasmic domain with two ITIM motifs (2, 3, 8, 9). Of four potential human LAIR1 splice variants, LAIR1b has a 17 aa deletion within the ECD, but outside the Ig domain. LAIR1c differs from LAIR1b by one aa. LAIR1d has a 78 aa cytoplasmic truncation and lacks ITIM motifs. Human LAIR1 ECD shares <45% aa sequence identity with mouse, rat, bovine or canine LAIR1 ECD, but all are functional orthologs. Humans, but not rodents, also express the 152 aa secreted protein LAIR2, which shares 83% aa sequence identity with the LAIR1 ECD up to aa 140 and can block LAIR1 collagen binding (1, 2). A soluble form of LAIR1 found in plasma and urine also binds collagen (10). Adhesion of LAIR1 to collagens in the extracellular matrix, transmembrane collagens expressed by tumor cells, or antibody-mediated crosslinking of LAIR1, inhibits signals relayed by ITAM-bearing receptors and some cytokine-mediated signals (6-8, 13). Processes that are inhibited include B and T cell receptor-mediated activation, NK and T cell‑mediated cytotoxicity, and basophil degranulation (1-4, 8). LAIR1 is reduced or absent on chronic lymphocytic leukemia (CLL) B cells, and some B and DC cells in systemic lupus erythematosus (SLE). Its under‑expression potentially enhances CLL proliferation and SLE immune responses (7, 11, 12).

1. Meyaard, L. (2008) J. Leukoc. Biol. 83:799.
2. Meyaard, L. et al. (1997) Immunity 7:283.
3. Lebbink, R.J. et al. (2004) J. Immunol. 172:5535.
4. Ouyang, W. et al. (2003) Biochem. Biophys. Res. Commun. 310:1236.
5. Verbrugge, A. et al. (2006) J. Leukoc. Biol. 79:828.
6. Lebbink, R.J. et al. (2006) J. Exp. Med. 203:1419.
7. Bonaccorsi, I. et al. (2010) PLoS ONE 5:e15080.
8. Tang, X. et al. (2009) J. Immunol. 182:5446.
9. Brondijk, T.H.C. et al. (2010) Blood 115:1364.
10. Olde Nordkamp, M.J. et al. (2011) Arthritis Rheum. 63:3749.
11. Poggi, A. et al. (2008) Leukemia 22:980.
12. Colombo, B.M. et al. (2012) PLoS ONE 7:e31903.
13. Rygiel, T.P. et al. (2011) Mol. Immunol. 49(1-2):402.

Bioinformatics

• Uniprot:
  • NP_002278()