MAMMALIAN HEMOGLOBINS 319 



Fig. 45. Comparison of murine hemoglobins analyzed by "fingerprinting." 



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Tryptic digests were chromatographed with n-butanol : acetic acid: water (4:1:5) for 

 16 hours and electrophoresed in pyridine : acetic acid:water (1:10:289) buffer, pH 3.7 

 developed with ninhydrin. 



Left. Single hemoglobin of strain C57BL mice. 



Right. Diffuse hemoglobin of strain BALB/c mice. 



In 1957 Rhinesmith et a/. 1054 established that the hemoglobin molecule is composed 

 of four polypeptide chains of two different kinds, referred to as alpha and beta chains. 

 Through the use of reversible dissociation and reassociation of mixtures of A and S 

 hemoglobins Vinograd et a/. 1346 showed that the alpha chains of the half-molecules of 

 A and S hemoglobins were similar, whereas the beta chains were not. Thus, they argued 

 that the chemical difference between A and S hemoglobins occurred in the beta chain. 

 In view of the basis of the template theory of protein synthesis, it became of interest to 

 know whether the other peptides in which alterations had been observed (that is, no. 

 23 and no. 26) were in the same chain as peptide no. 4. The alpha and beta chains can 

 be separated electrophoretically in a detergent (sodium dodecylsulphate in veronal 

 buffer), ionic strength 0.12, /?H 8.6, or by urea chromatography on ion-exchange resins 

 (Amberlite IRC-50/XE64 or "CG50") using 2-8 M urea, pH adjusted to 1.9 with 

 HC1. 635, 1395 "Fingerprints" of peptide hydrolysates of each half-molecule showed 

 that approximately one-half of the peptides of the hemoglobin molecule were present 

 in the alpha chain, and the remaining peptides were in the beta chain. Peptides no. 4 

 and no. 26 were found in the beta chain, and the alpha chain contained peptide no. 23. 



