Reactivity of the human hemoglobin "dark side"

Paolo Ascenzi, Loris Leboffe, Fabio Polticelli

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Summary: Ligand binding to the heme distal side is a paradigm of biochemistry. However, X-ray crystallographic studies highlighted the possibility that O2 and NO2 - may bind to the proximal heme side of ferrous human hemoglobin (Hb) α-chains complexed with the α-hemoglobin stabilizing protein and to ferric human hemoglobin β-chains, respectively. Strikingly, the role generally played by the proximal HisF8 residue is played by the distal HisE7 side chain forming the trans axial ligand of the heme-Fe atom. This: i) brings to light that Hb may utilize both heme distal and proximal sides for ligand discrimination, ii) draws attention to the nonequivalence of α- and β-chains, and iii) highlights the possibility that partially unfolded Hb derivatives may display transient ligand-binding properties different from those of the native globin.

Original languageEnglish
Pages (from-to)121-126
Number of pages6
JournalIUBMB Life
Volume65
Issue number2
DOIs
Publication statusPublished - Feb 2013

Fingerprint

Hemoglobins
Heme
Ligands
Biochemistry
Globins
X-Rays
Derivatives
X rays
Atoms
Proteins

Keywords

  • α- and β-chain nonequivalence
  • distal heme side
  • human hemoglobin
  • ligand discrimination
  • proximal heme side
  • transient ligand-binding properties

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Clinical Biochemistry
  • Molecular Biology
  • Genetics

Cite this

Ascenzi, P., Leboffe, L., & Polticelli, F. (2013). Reactivity of the human hemoglobin "dark side". IUBMB Life, 65(2), 121-126. https://doi.org/10.1002/iub.1121

Reactivity of the human hemoglobin "dark side". / Ascenzi, Paolo; Leboffe, Loris; Polticelli, Fabio.

In: IUBMB Life, Vol. 65, No. 2, 02.2013, p. 121-126.

Research output: Contribution to journalArticle

Ascenzi, P, Leboffe, L & Polticelli, F 2013, 'Reactivity of the human hemoglobin "dark side"', IUBMB Life, vol. 65, no. 2, pp. 121-126. https://doi.org/10.1002/iub.1121
Ascenzi P, Leboffe L, Polticelli F. Reactivity of the human hemoglobin "dark side". IUBMB Life. 2013 Feb;65(2):121-126. https://doi.org/10.1002/iub.1121
Ascenzi, Paolo ; Leboffe, Loris ; Polticelli, Fabio. / Reactivity of the human hemoglobin "dark side". In: IUBMB Life. 2013 ; Vol. 65, No. 2. pp. 121-126.
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