Derivatives of Hemoglobin

Alternatively, sites adjacent to an abnormal gene may differ from those on normal chromosomes. Such linked polymorphisms have been found for the sickle cell gene and for several -thalassemias. Because different individuals having a particular hemoglobin abnormality will not 

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Westenberger, U., Thanner, S., Ruf, H. H., Gersonde, K., Sutter, G., and Trentz, O. (1990). Formation of free radicals and nitric oxide derivative of hemoglobin in rats during shock syndrome. Free Radical Res. Commun. 11, 167-178. 

Because the erythrocyte is a relatively simplified cell with a circumscribed function it would seem that superoxide dismutase must act to prevent a deleterious effect of O2 on the erythrocyte s capacity to transport oxygen. Superoxide might react with hemoglobin to form a derivative which cannot reversibly bind O . One such reaction is to mediate the formation of methemoglobin, the derivative of hemoglobin in which the Fe in heme is converted to Fe . The ability of O to react with hemoglobin to form methemoglobin has been proposed to occur 201,207-209) jjj... 

In the presence of oxygen, dissolved hemoglobin is slowly oxidized to methemoglobin, a derivative of hemoglobin in which the iron is present in the ferric (Fe +) state. In metHb, the ferric ion is bound tightly to a hydroxyl group or to some other anion. The heme porphyrin (protoporphyrin IX) that contains an Fe + ion is known as hemin. 

In the next section the structures of various derivatives of hemoglobin and its models are presented, and the relationship of structure to ligand-binding properties is examined. Although there is now a wealth of thermodynamic data available from model systems, attention is focused primarily on those for which structural data are also available. 

The ferryl derivative of hemoglobin then oxidises HK, finally returning to the ferri- state. 

Microcrystallographic or microchemical techniques rely on the fact that certain derivatives of hemoglobin have the tendency to crystallize. It is possible to find either crystals of hematin or crystals of hemochromogen (depending on whether the hem molecule is degraded to an iron(II) or iron(III) pigment). 

Watson CJ (1946) Some newer concepts of the natural derivatives of hemoglobin. Blood 1 99-120... 

Petcu, L. C. Turcu, G. Rosoiu, N. Comparative study of certain ferric and ferrous derivatives of hemoglobin labeled with HPT. Rom. J. Biophys. 2002,12, 53-58. 

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