Hemolysates reduce iron released from transferrin

H. Zhan, Simeon Pollack, J. Weaver

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Transferrin donates iron to reticulocytes as follows: it binds to a receptor on the reticulocyte surface; the complex is endocytosed; both irons are released and the transferrin is recycled to the cell exterior. It has been proposed that the trigger for iron release after transferrin endocytosis is acidification of the endocytic vesicle. But this could account for removal of only one of transferrin's two irons, since only one of the irons is labile at acid pH. Moreover, iron continues to be removed from transferrin when acidification of the vesicle is blocked by a chloride-transport inibitor. Thus a detailed explanation of iron removal from transferrin remains elusive. In earlier work we showed that iron can be removed from transferrin by whole hemolysates and also by the combined action of hemoglobin and ATP at pH 7. We now show that the iron released from transferrin by hemolysates, and by hemoglobin and ATP, is in the Fe(II) oxidation state. We also show that ADP and DPG can substitute for ATP and that NADH and NADPH can substitute for the hemoglobin, although with these substitutions Fe(II) is generated less efficiently. The reductive release of iron from transferrin is rapid enough to account for all the iron processed by a young reticulocyte. We speculate that transferrin iron may be reduced to Fe(II) before reaching the mitochondria.

Original languageEnglish (US)
Pages (from-to)203-207
Number of pages5
JournalAmerican Journal of Hematology
Volume31
Issue number3
StatePublished - 1989

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Transferrin
Iron
Reticulocytes
Adenosine Triphosphate
Endocytosis
Hemoglobins
Blood Substitutes
Transport Vesicles
NADP
NAD
Adenosine Diphosphate
Chlorides
Mitochondria
Acids

ASJC Scopus subject areas

  • Hematology

Cite this

Hemolysates reduce iron released from transferrin. / Zhan, H.; Pollack, Simeon; Weaver, J.

In: American Journal of Hematology, Vol. 31, No. 3, 1989, p. 203-207.

Research output: Contribution to journalArticle

Zhan, H. ; Pollack, Simeon ; Weaver, J. / Hemolysates reduce iron released from transferrin. In: American Journal of Hematology. 1989 ; Vol. 31, No. 3. pp. 203-207.
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