Recombinant Macaca mulatta T-cell surface glycoprotein CD4 (CD4), partial (Active)

CD4 serves as the primary receptor for HIV envelope glycoprotein gp120 and plays a central role in T-cell activation, making it a critical target for studying viral entry mechanisms and immunomodulatory therapies in non-human primate models. This protein, spanning residues 26–396 and expressed in mammalian cells to preserve native glycosylation and disulfide bonding patterns, demonstrates quantifiable binding activity with an EC50 of 2.057–2.679 ng/mL against an anti-CD4 recombinant antibody in functional ELISA, providing a validated basis for therapeutic antibody epitope mapping, competitive inhibition screening, and blocking antibody development. The defined binding kinetics support its use in surface plasmon resonance and biolayer interferometry experiments for affinity characterization of CD4-targeted biologics and small-molecule inhibitors. With purity exceeding 95% by SDS-PAGE and endotoxin levels below 1.0 EU/μg, this protein meets the quality thresholds commonly required for ligand-receptor interaction studies and serves as a positive control in binding assays evaluating immunotherapeutic candidates.