SUBSPECIFICITIES OF ANTI-M AND ANTI-N ANTIBODIES TESTED WITH CHEMICALLY-MODIFIED ANTIGENS

The division of anti-M and anti-N antibodies into subspecificities bas ed on dependence of the epitope on amino acid residue 1 or 5 of GPA, a mino groups and sialic acid residues is presented. The Workshop antibo dies were classified into the subspecificities by testing their reacti vity with GPA-M or GPA-N untreated. and modified by Edman degradation (release of the first amino acid residue), periodate oxidation, N-acet ylation and desialylation. Most antibodies, according to former result s, belonged to the group recognizing the blood group M- or N-related e pitope dependent on the first amino acid residue, amino group and sial ic acid residues, but other subspecificities were also found.