Acetylation of human hemoglobins by cord blood ribosomal and postribosomal acetyltransferases

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6156910

Qiu, C C; Kasten-Jolly, J; Abraham, E C

The authors have been interested in human fetal hemoglobin acetylation and have focused on search of an acetyltransferase that can acetylate this hemoglobin. Cord blood ribosomal and postribosomal acetyltransferases have been partially purified by histone-Sepharose 4B affinity chromatography. Analysis of Dextran 40 fractionated cells has indicated that the enzyme is present only in reticulocytes and young erythrocytes, and mature erythrocytes are devoid of this enzyme. Enzymes prepared from the ribosomal and postribosomal sources showed similar temperature, pH, and cation dependence. In vitro acetylation of Hb F0, Hb A0 and native el, US , and chains with ( UC)acetyl-CoA in the presence of these enzyme preparations failed to show any specificity to any one of the hemoglobins. No significant differences in hemoglobin acetylation were seen between the two types of enzymes. However, acetylation of Hb F0 and el chains did produce Hb F/sub Iac/ (Hb F/sub I/ or Hb F/sub Ic/) and el/sub Iac/ (el/sub I/ or el/sub Ic/), respectively. Peptide analyses showed that the el chain NH2-terminus and other sites were being acetylated. Thus, site specificity is seen only when the ribosomal enzyme acts on ribosome-bound nascent chains. It is also possible that the presence of free enzyme, acetyle-CoA and potential hemoglobin substrates in the cytoplasm may lead to the formation of some Hb F/sub Iac/ and small amounts of other unidentified acetylated hemoglobins in red cells.

• Research Organization: Medical College of Georgia, Augusta
• OSTI ID: 6156910
• Report Number(s): CONF-870644-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACETYLATION
ACYLATION
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHROMATOGRAPHY
ENZYMES
ERYTHROCYTES
GENETIC MAPPING
GLOBIN
HEMOGLOBIN
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
MAN
MAPPING
MATERIALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PIGMENTS
PORPHYRINS
PRIMATES
PROTEINS
REACTION KINETICS
SEPARATION PROCESSES
TEMPERATURE DEPENDENCE
TRACER TECHNIQUES
TRANSFERASES
VERTEBRATES