Deoxyhemoglobin solutions

As oxyhemoglobin solutions in air are liable to contain appreciable amounts of deoxyhemoglobin, it is astonishing that a reaction of OJ with deoxyhemoglobin has apparently not been considered ... 

Figure 9 shows force laws for phosphatidylcholine bilayers (Lis et al, 1982), determined by the osmotic stress method. Similar data were obtained for DNA samples (Rau et al., 1984). The characteristic length governing decay of the force is about 3 A for both systems. Interactions of this kind can also be important for protein aggregates. Prouty et al. (1985) used the osmotic stress method to determine the phase diagram of sickle cell hemoglobin (Fig. 10). At a critical osmotic pressure, which is temperature dependent, a solution of deoxyhemoglobin S collapses to a gel, with a large change in volume. One of the strengths of the osmotic stress method is that it provides additional information that can be used for thermodynamic analysis of the system.

Val 1-NAl, Lys 82-EF6, and His 143-H21) and deoxy Hb-S does not produce configuration changes which influence the aggregation of the molecules (B35). Moreover, cyanate (HN=C=0) which carbamylates amino terminal residues of proteins (R—NH—CO—NH2) is an effective inhibitor of sickling of erythrocytes in vitro and of gelling of concentrated solutions of deoxyhemoglobin S (C9). Addition of some specific hemoglobin variants, Hb-O-Arab or 02 2 (M16) and Hb-Korle Bu... 

Fig. 8.18. Cl excess line width as a function of NaCl concentration in solutions of human oxy and deoxy hemoglobin at pH 7.45 to 7.50. The excess line widths were proportional to the hemoglobin concentration and have here been normalized to a protein concentration of 1,5 % by weight. Key to the symbols o, (i and refer to oxyhemoglobin V refers to methemoglobin , D and refer to deoxyhemoglobin. The full curves are theoretical ones calculated with the use of Eq. (8.42) using the following parameters for oxyhemoglobin Kg = 10 M , ngCT B)" = 5.8 10 sec , ...

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