Recombinant Human CD52 Protein (hFc)

Measured by functional ELISA. Immobilized recombinant human CD52-hFc binds alemtuzumab with an EC50 in the range of 5–30 ng/mL.

CD52 is one of the smallest functional surface antigens in immunology: after maturation it presents as a 12-amino-acid, heavily glycosylated peptide anchored to the membrane by a GPI lipid anchor, abundantly expressed on virtually all mature lymphocytes, monocytes and eosinophils but absent from stem and plasma cells. The humanized anti-CD52 antibody alemtuzumab exploits this dense, non-modulating expression to deplete lymphocytes, and is established for relapsing-remitting multiple sclerosis and, historically, chronic lymphocytic leukemia. Because the native peptide alone is too small to support antibody binding assays, our CD52 antigen is presented as a dimeric human Fc fusion, restoring avidity and assay convenience for alemtuzumab biosimilar QC, anti-CD52 screening and tolerance/immunology studies.