KIR2DL4 (also known as CD158d, 2DL4, p49, KIR103) is a type I transmembrane protein of the killer cell Ig-like receptor（KIR） family expressed in all NK cells and some T cells. KIR2DL4 is a unique KIR. KIR members with two Ig-like domains (2D) usually express domains D1 and D2,but KIR2DL4 expresses D0 and D2. Other long-tailed(L) KIR have two cytoplasmic inhibitory signaling domains (ITIM), but KIR2DL4 has one ITIM. KIR2DL4 is a NK cell-activating receptor with inhibitory potential. The tyrosine-phosphorylated cytoplasmic tail of KIR2DL4 bound the Src homology 2-containing phosphatases 1 and 2, as did the tail of the inhibitory receptor KIR2DL1. KIR2DL4 activates the cytotoxicity of NK cells, despite the presence of ITIM.

·Description
Recombinant human KIR2DL4 produced by transiently transfected human cell is the extracellular domain (Accession # Q99706)(His22-His242) of human KIR2DL4 fused with a polyhistidine tag at the C-terminus.

·Quality Control
Biological activity: The ED50 of rHuKIR2DL4 as measured by its ability to inhibit antiKIR2DL4 antibody induced IFNγ
secretion by NK92 human natural killer lymphoma cells is 0.3-1μg/mL.
Purity: Greater than 90.0% as determined by:
(a) Analysis by RP-HPLC.
(b) Analysis by reducing and non-reducing SDS-PAGE Silver Stained gel.
Amino-Acid Sequence: Predicted N terminal amino acid is His22.
Endotoxin: Less than 0.1ng/μg (1EU/μg) of rHuKIR2DL4.

·Formulation
Sterile and lyophilized from a 0.2 μm filtered solution in PBS.

·Reconstitution
It is recommended to reconstitute the lyophilized rHuKIR2DL4 in sterile water not less than 100μg/ml。

·Storage
Lyophilized rHuKIR2DL4 although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution rHuKIR2DL4 should be stored at 4°C between 2-7 days and aliquots of reconstituted samples containing 0.1% BSA are stable up to 3 months below -18°C for future use.

Please avoid freeze-thaw cycles.