Nuclear magnetic resonance studies on the cooperative oxygen binding in hemoglobin are reviewed. First brief descriptions of NMR methods of variousl nuclei are made by typical examples found in hemoglobin studies. Then the recent interests in hemoglobin are categorized in four chapters, the allosteric transition between the two states with different functional properties, the presence of hemoglobin molecules with intermediate structure, α-β nonequivalency and the location of the interaction energy. Those topics are discussed mainly with NMR results in order to show the merit and limitation of the technique.
Recent progress in cell biology is demonstrating that the plasma membrance plays the important roles responsible for the growth and the differentiation of animal cells, as a mediator of cell-to-cell interaction. Cell electrophoresis is one of the methods of characterizing the cell surface with a minimal of external influence. The charge pattern of the cell surface reflects ionogenic groups at glycocalix or cell coat, a carbohydrate-rich layer, which locates the most peripheral region of plasma membrane. Changes which have been produced in the cell electrophoretic mobility by biophysical and biochemical means permit deductions about the nature of membrane structures. The ionogenic substances at the cell surface are sialic acid, mucopolysaccharides, lipids, RNA and proteins. These substances on the cell surface was discussed in connection with cell growth and differentation.
Recent progress in the understanding of hydrogen exchange and its use in studies of the fluctuation of the protein structure are reviewed. By means of an infrared spectroscopic observation of the hydrogen exchange reaction, a simple and reliable method of determining the number of the peptide-peptide hydrogen bonds in a given protein molecule in its aqueous solution is proposed. Then, the mechanisms of hydrogen exchange in protein are critically examined comparing hydrogen exchange kinetics with other physical method for several proteins. The graphic method of evaluation of the fluctuation amplitude at various levels and the results of its application to myoglobin structure are shown. In addition, the fluctuation of the side chain is also discussed.