LAIR1 (leukocyte-associated Ig-like receptor-1, designated CD305) is an ~40kD 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 144aa extracellular domain (ECD) with one collagen-binding C2-type Ig-like domain, and a 101aa cytoplasmic domain with two ITIM motifs (2, 3, 8, 9). Of four potential human LAIR1 splice variants, LAIR1b has a 17aa 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 152aa secreted protein LAIR2, which shares 83% aa sequence identity with the LAIR1 ECD up to aa140 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).
Source:Recombinant protein corresponding to aa22-163 from human LAIR1, fused to his-tag at C-terminal, NS0-derived.
Molecular Weight:~28-33kD
Endotoxin:<0.10EU/1ug (LAL method).
Storage and Stability:Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
仕様
Size：50ug
Source Antigen：Recombinant
Grade：Highly Purified
Purity：~95% (SDS-PAGE)
Form：Supplied as a lyophilized powder in PBS. Reconstitute in 300ug/ml PBS.
