Mouse NKR-P1C(B6) receptor corresponding to NK1.1 alloantigen is one of the most widespread surfacemarkers of mouse NK and NKT cells in C57BL/6 mice detected by monoclonal antibody PK136. Althoughfunctional studies revealed the ability of this receptor to activate both natural killing and production ofcytokines upon antibody crosslinking, the ligand for NKR-P1C(B6) remains unknown.
In order to initiate ligand identification, structural studies, and epitope mapping experiments, we developed a simple and efficient expression and purification protocol allowing to produce large amounts of pure soluble monomeric mouse NKR-P1C(B6). Our protein encompassed approximately half of the stalk region and the entire C-terminal globular ligand binding domain.