Fine Characterization of a Series of New Monoclonal Antibodies Directed against Glycophorin A

Objectives: Glycophorins A (GPA) and B (GPB) are the major sialoglycoproteins of the human erythrocyte (RBC) membrane. To prepare tools for the analysis of GPA and GPB, we produced a series of new monoclonal antibodies (mAbs) that identified epitopes of GPA. Methods: Seven murine monoclonal antibodies directed to glycophorin A (GPA) were fully characterized by agglutination of untreated and enzyme‐treated human erythrocytes, inhibition of agglutination using chemically modified glycophorins and peptides from GPA, immunoblotting, and binding to synthetic peptides on plastic pins. Results: The antibodies identify epitopes located on four different portions of GPA: (1) NaM13‐6D2 binds to the N‐terminal portion of GPA and GPB carrying the N blood group antigen; (2) NaM26‐3F4 recognizes the homologous portion of GPA and GPB corresponding to their amino acids 6‐26; (3) NaM10‐2H12, NaM16‐IB10 and NaM10‐6G4 are specific for the amino acid sequence 38‐45 of GPA; and (4) NaM37‐5F4 and NaM13‐4E4 bind to the amino acid residues 119‐124 located on the intracellular ponion of GPA. Conclusion: These antibodies represent precise tools to investigate GPA and related molecules in different cells and tissues.