Concanavalin A binding sites on the erythrocytes of normal and genetically dystrophic chickens

Red blood cells (RBCs) were obtained from genetically dystrophic chickens (Dy) and age-matched controls (C). Dy-RBCs had a lower titer of agglutination to concanavalin A (Con A) compared to C-RBCs. In order to ascertain the difference in agglutination, Con A binding on RBCs was studied, using 125I-labeled Con A ([125I]Con A) and ferritin conjugate to Con A (Fer-Con A). Kinetic analysis of [125I]Con A binding to Dy-RBCs showed a reduction of major binding sites of Con A. There was no difference in the apparent association constant for the major binding sites of Con A between Dy-RBCs and C-RBCs. Quantitative analysis of Con A binding site distribution on RBCs using Fer-Con A showed a remarkable diminution of ferritin particles tagged on the surface of Dy-RBCs. There was no significant difference in the distribution pattern of ferritin particles between Dy-RBCs and C-RBCs.