Hemoglobin Einstein: Semisynthetic deletion in the B-helix of the α-chain

Sonati Srinivasulu, Belur N. Manjula, Ronald L. Nagel, Ching Hsuan Tsai, Chien Ho, Muthuchidambaran Prabhakaran, Seetharama A. Acharya

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

The influence of the deletion of the tetra peptide segment α 23-26 of the B-helix of the ot-chain of hemoglobin-A on its assembly, structure, and functional properties has been investigated. The hemoglobin with the deletion, ss-Hemoglobin-Einstein, is readily assembled from semisynthetic α1-141des23-26 globin and human βA-chain. The deletion of α23-26 modulates the O2 affinity of hemoglobin in a buffer/allosteric effector specific fashion, but has little influence on the Bohr effect. The deletion has no influence on the thermodynamic stability of the α1β 1 and the α1β2 interface. The semisynthetic hemoglobin exhibits normal intersubunit interactions at the α1β1 and α1β2 interfaces as reflected by 1H-NMR spectroscopy. Molecular modeling studies of ss-Hemoglobin-Einstein suggest that the segment α 28-35 is in a helical conformation, while the segment α 19-22 is the nonhelical AB region. The shortened B-helix conserves the interactions of α1β1 interface. The results demonstrate a high degree of plasticity in the hemoglobin structure that accommodates the deletion of α23-26 without perturbing its overall global conformation.

Original languageEnglish (US)
Pages (from-to)1266-1275
Number of pages10
JournalProtein Science
Volume13
Issue number5
DOIs
StatePublished - May 1 2004

Keywords

  • H-NMR spectroscopy
  • Molecular modeling
  • Oxygen affinity
  • Shortened B-helix
  • Stuctural plasticity
  • Subunit interfaces
  • Thermodynamic stability

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

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  • Cite this

    Srinivasulu, S., Manjula, B. N., Nagel, R. L., Tsai, C. H., Ho, C., Prabhakaran, M., & Acharya, S. A. (2004). Hemoglobin Einstein: Semisynthetic deletion in the B-helix of the α-chain. Protein Science, 13(5), 1266-1275. https://doi.org/10.1110/ps.03567804