Ribosome-free hemolysates

The next phase of the study has been concerned with the effects of heme on the synthesis and assembly of the a and p chains of hemoglobin (Vanderhoff et cd., 1967 Tavill et al., 1967). Reticulocytes of iron-deficient rabbits or of rabbits made anemic by acetylphenyl-hydrazine (APH) were incubated with isotopically labeled amino acids in the presence and absence of added hemin. When globin was prepared from the ribosome-free hemolysate which had undergone no further purification, the specific activities (S.A.) of the separated a and p chains were almost equal and the cc/p ratio was approximately... 

If, however, the reticulocytes were incubated without added iron or hemin (control), and the hemoglobin was first isolated from the ribosome-free hemolysate by column chromatography on carboxymethyl-cellulose or Sephadex G 100, the a/p ratio was much less than one (Tables 3 and 4). The addition of hemin to the incubation medium resulted in an increase in the specific activity of the globin and of the... 

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