Studies on Mammalian Red Cells 



77 



Table I 



Radioactivities of Samples of Protoporphyrin Ester, Globin Glycine (DNP) 



AND StROMATIN GLYCINE (DNP) 



Investigations on Globin Synthesis 



In the experiments on rats to which reference has aheady 

 been made, DL-vahne labelled with ^*C on the ^^m-methyl 

 groups was injected together with the labelled glycine. The 

 two amino-acids were isolated from crystalline haemoglobin 

 as 2:4 dinitrophenyl (DNP) derivatives (Perrone, 1951). 

 Valine residues supply the terminal amino groups of rat haemo- 

 globin and terminal valine was therefore isolated by treating 

 the intact protein with fluorodinitrobenzene followed by 

 hydrolysis and chromatographic^ separation. The non- 

 terminal valine and also glycine were obtained by similar 

 treatment of the residual hydrolysate. 



Table II shows the radioactivities of the terminal and non- 

 terminal valine residues in the haemoglobin at various intervals 

 after administration of the labelled amino-acids. It appears 

 that the two types of valine residue have exactly the same 

 activity at any one time, the differences being less than the 



