Recombinant Human Sialic acid-binding Ig-like lectin 15 (SIGLEC15), partial (Active)

SIGLEC15 has emerged as a promising immune checkpoint target distinct from the PD-1/PD-L1 axis, making functional recombinant forms of this receptor essential for immuno-oncology drug discovery. This partial construct spans the extracellular region (aa 20–263), encompassing the Ig-like V-type and C2-type domains critical for sialic acid recognition, and its production in mammalian cells supports native-like glycosylation and conformational integrity. Functional ELISA confirms binding activity against an anti-SIGLEC15 recombinant antibody with an EC₅₀ of 12.42–16.08 ng/mL, providing a validated basis for receptor-ligand interaction assays, blocking antibody screening, and therapeutic antibody epitope mapping. With purity exceeding 90% by SDS-PAGE and endotoxin levels below 1.0 EU/μg, this N-terminal His-Myc-tagged protein satisfies the quality criteria typical for SPR- or BLI-based affinity characterization, competitive inhibition studies, and use as a positive control in immune checkpoint binding assays.