Myosin in adult and neonatal human erythrocyte membranes

The heavy chain of myosin can be detected in human red cell membranes by immunoblot analysis with antiplatelet myosin antibodies. Neonatal red cell membranes have more immunoreactive myosin than adult membranes. Membranes from young adult red cells contain more immunoreactive myosin than membranes from old adult red cells. In contrast, young and old neonatal red cells have equivalent mounts of myosin. Erythrocyte myosin is present in a membrane fraction enriched in integral membrane proteins but is not found in cytoskeletal preparations.