The acetylated and/or glycosylated hemoglobins present in newborns and adults with elevated levels of Hb F due to DeltaBeta-thalassemia, Beta -thalassemia, Beta+-thalassemia, HPFH and leukemia will be separated and quantitated by affinity chromatographic and Biorex 70 chromatographic procedures and these hemoglobins will be subsequently characterized. The following directions will be followed to study the mechanism of acetylation of hemoglobins in the newborns and adults: 1) Using colonies of BFUe's of peripheral blood, it will be determined whether the acetylation of Hb F occurs primarily in mature or immature erythroid cells or in a certain clone of erythroid cells. 2) It will be determined whether embryonic and fetal hemoglobins are acetylated in leukemia cell line K-562 induced with hemin. 3) By determining the affinity of acetylated and non-acetylated Gamma chains for Alpha chains it will be determined whether a deficiency of Alpha chains, as in Alpha-thalassemia, can influence the formation of acetylated Hb F. 4) Using intact cell or mRNA-dependent cell-free systems it will be found out whether acetylation occurs during the growth of the Gamma chains on the polyribosomes, and if so, the appropriate length of the nascent chains at the time of acetylation will be determined. 5) It will be determined whether the acetylation is under metabolic control and influenced by the levels of acetyl-CoA, acetyltransferase and decetylase. 6) Acetyltransferase and deacetylase from human and chicken blood cells will be purified and the specificity with regard to different hemoglobin substrates and the regulatory factors, including inhibitors and stimulators and their mechanism of action, will be determined.
