Freeze-etch localization and distribution of concanavalin a in normal and irreversibly sickled erythrocytes

Normal red blood cells and irreversibly sickled red cells (ISCs) were incubated in Concanavalin A (Con A) prior to freeze-etching. The Con A molecules could be visualized on the etched face of the cells without conjugating the Con A to a larger molecule. No differences in the number or distribution of the Con A binding sites were observed between normal red cells and ISCs. Moreover, the number and distribution of the intramembranous particles (IMP) present on the fracture face of the cytoplasmic membrane leaflet were the same in normal cells and ISCs. Thus, the membrane differences that do exist between normal red cells and ISCs in terms of cell shape and adhesiveness are not reflected in Con A binding or IMP number and distribution.