HbS-Savaria: The anti-polymerization effect of a single mutation in human α-chains

Sonati Srinivasulu, A. Seetharama Acharya, Muthuchidambaran Prabhakaran, Mary E. Fabry, Raouf Alami, Steven N. Fiering, Eric E. Bouhasirra, Ronald L. Nagel

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Recombinant α-Savaria globin (αS49R) was assembled with βS chains by the alloplex intermediate pathway to generate tetrameric rHbS-Sarvaria (α2S49Rβ 2E6V ) that exhibited normal O2 affinity and co-operatively at pH 7.4. Allosteric effectors, 2,3-DPG, L35, and NaCl increased O2 affinity by 15%. Bohr effects were similar for rHbS-Savaria and HbS (0.38 ± 0.025 vs. 0.46 ± 0.03, respectively). The C SAT of HbS increased from 16.7 ± 0.8 to 27.0 ± 1.0 g/dL. Co-polymerization demonstrated inhibition predominantly by the Cis-dimer. Molecular modeling indicated that the positive charge at α-49 generated a strong anion-binding site and reduced flexibility of the CD-region by restricting movement in the E and F helices. The molecular distance between Arg-49 and Asn-78 in the neighboring double strand decreased, and electrostatic repulsion between the inter-double strands increased, resulting in inhibition of polymerization. The Savaria mutation may be useful for the design of super-inhibitory α-chains and gene therapy of sickle cell anemia.

Original languageEnglish (US)
Pages (from-to)523-532
Number of pages10
JournalProtein Journal
Volume26
Issue number8
DOIs
Publication statusPublished - Dec 1 2007

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Keywords

  • Gene therapy
  • Hemoglobin S
  • Hemoglobin Savaria
  • Polymerization inhibition
  • Sickle cell anemia

ASJC Scopus subject areas

  • Analytical Chemistry
  • Bioengineering
  • Biochemistry
  • Organic Chemistry

Cite this

Srinivasulu, S., Acharya, A. S., Prabhakaran, M., Fabry, M. E., Alami, R., Fiering, S. N., ... Nagel, R. L. (2007). HbS-Savaria: The anti-polymerization effect of a single mutation in human α-chains. Protein Journal, 26(8), 523-532. https://doi.org/10.1007/s10930-007-9089-9