Human haemoglobins

This chapter highlights the methods used for the study of structures of normal, modified, and mutant hemoglobins in human. Isoelectric focusing and electrophoresis have provided convenient and extremely sensitive methods. These methods have also been useful in functional studies of hemoglobin, but less useful than column chromatography for preparative purposes. Electrophoresis and isoelectric focusing measures the biosynthesis of hemoglobin and its component globin chains. Several properties include the tetramer-dimer equilibrium, binding of ligands to haem, and binding of organic phosphates. Liganded hemoglobin can be separated from deoxyhemoglobin by isoelectric focusing because of the Bohr effect. Polyacrylamide plate is focused in one direction to create a pH gradient, and the sample is introduced into a trough, which allows electrophoresis to be performed at right angles to the focusing. By focusing at partially liganded HbA, the ATP migrates through the bands.