CHROMATOGRAPHIC HETEROGENEITY OF HUMAN-FETAL HEMOGLOBIN

Minor fetal hemoglobins in red cell hemolysates of newborn and adults with elevated levels of Hb F have been separated and quantitated by Biorex 70 column chromatography. In addition to Hb FI, other minor hemoglobin zones eluting before FI, pre-FI, and after FI, post-FI, have been observed. The relative amounts of the two pre-FI zones and FI are higher in the red cells of adults with 97-100% Hb F (homozygous hereditary persistence of fetal hemoglobin, homozygous δβ-thalassemia and homozygous β0-thalassemia) than in the red cells of an adult with homozygous β+-thalassemia with 66% Hb F, a child with a trisomy-D-13 having 38% Hb F, and in two newborn. Hb F was glycosylated in vitro with [14C]glucose or [14C]glucose 6-phosphate, and was acetylated using chicken reticulocyte lysate or a crude acetyltransferase preparation isolated from the same lysate with [14C]acetyl-CoA as substrate. Chromatographic analyses indicated that the Hb FI zone can be formed both by glycosylation and acetylation of Hb F, and that pre-FI zones can be products of the reaction of Hb F with phosphorylated glycolytic intermediates. Biosynthesis of minor hemoglobins in reticulocytes was studied with [14C]leucine in the presence and absence of cycloheximide and by pulse-chase. The resulting data indicate that Hb FI synthesis is dependent upon Hb F synthesis and that the posttranslational modification may take place at an early stage in Hb F synthesis. © 1979.