310 



VII. COMPARATIVE BIOCHEMISTRY OF HEMOGLOBINS 



suggest differences in the structure of the prosthetic group. Schon- 

 heimer's demonstration that the prosthetic group of myohemoglobin 

 is a type IX protohematin {2Jf57) enables us to say that, in all types 

 of hemoglobin so far examined, only one arrangement of the side 

 chains has been observed, and that, in only one case, that of Spiro- 

 graphis hemin, is there a difference in the composition of any of the 

 side chains. 



3.5. Influence of Protein on the Spectrum 



Small differences have been observed in the position of the absorption 

 bands of the oxyhemoglobins of various species. These differences disappear 



3.0 



©8 2.6 



E 

 W 



Fig. 1. Relation of log K to the span (after Anson, Barcroft, et al., IL'f). 



on denaturation of the globin and are no longer found in the denatured 

 globin hemochromes. Barcroft's school (64,141) has related the shift in the 

 band, when oxyhemoglobin is transformed into carboxyhemoglobin, to the 



