Specificity of IgA cold agglutinins: anti‐Pr1

摘要: Monoclonal cold agglutinins have usually been found to be IgM(k) and directed against the I/i antigens. Three IgA(k) were tested for antibody specificity. Based on following criteria, they shown Pr1 antigen of Pr1/Pr2/Pra system. The antigens reacting with inactivated by protease treatment human red cells neuraminidase demonstrable erythrocyte glycoproteins. terminal sugar determinant group these is N-acetylneuraminic acid (NANA), which not involved in I/i, but also Pr2 antigenicity. activity I activities distributed different glycopeptide fractions obtained from cell glycoproteins ficin cleavage Sephadex G-50 separation. Periodate oxidation glycoproteins, causes a shortening polyhydroxy side chain at C-6 C-9 NANA C-7 and/or C-8 derivative, resulted inactivation antigens, while remained unchanged was increased 16–64-fold. Dog gave no or diminished reactions three agglutinins, contrast reaction anti-Pr2. dog cells, heterogeneity Pr1h/Pr1d demonstrated. In spite determination Pr1h/Pr1d/Pr2 MN NANA, both systems unrelated. Blocking free e-lysine amino groups acetylation blocking carboxyl amidation inactivation, (like Pr2) unaffected. The anti-Pr1 specificity IgA predominance anti-I/-i IgM discussed respect inter-relations between immunoglobulin classes specificities agglutinins.