Allosteric properties of hemoglobin and the plasma membrane of the erythrocyte: New insights in gas transport and metabolic modulation

Within the red blood cell the hemoglobin molecule is subjected to modulation mechanisms, namely homo- and heterotropic interactions, which optimize its functional behavior to the specific physiological requirements. At the cellular level, these modulation mechanisms are utilized to perform a number of other functions that are not minor with respect to the basic function of oxygen transport. Here we report some key examples concerning: (i) the interaction of hemoglobin with band 3 and its influence on glucose metabolism; (ii) the role of the ligand-linked quaternary transition of hemoglobin in the control of ''NO bioactivity'' and of gas diffusion; (iii) the interaction of plasma membrane with the various oxidative derivatives of the hemoglobin molecule.