HbS-Savaria: the anti-polymerization effect of a single mutation in human alpha-chains

Recombinant alpha-Savaria globin (alpha(S49R)) was assembled with beta(S) chains by the alloplex intermediate pathway to generate tetrameric rHbS-Sarvaria (alpha (2) (S49R) beta (2) (E6V) ) that exhibited normal O(2) affinity and co-operatively at pH 7.4. Allosteric effectors, 2,3-DPG, L35, and NaCl...

Full description

Saved in:
Bibliographic Details
Published in:The protein journal 2007-12, Vol.26 (8), p.523-532
Main Authors: Srinivasulu, Sonati, Acharya, A Seetharama, Prabhakaran, Muthuchidambaran, Fabry, Mary E, Alami, Raouf, Fiering, Steven N, Bouhasirra, Eric E, Nagel, Ronald L
Format: Article
Language:English
Subjects:
Allosteric Regulation
Animals
Binding Sites
Heme - chemistry
Heme - metabolism
Hemoglobins, Abnormal - chemistry
Hemoglobins, Abnormal - genetics
Hemoglobins, Abnormal - metabolism
Humans
Mice
Mice, Inbred C3H
Mice, Inbred C57BL
Mice, Transgenic
Models, Molecular
Mutation - genetics
Oocytes - cytology
Oocytes - metabolism
Protein Conformation
Recombinant Proteins - genetics
Recombinant Proteins - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Recombinant alpha-Savaria globin (alpha(S49R)) was assembled with beta(S) chains by the alloplex intermediate pathway to generate tetrameric rHbS-Sarvaria (alpha (2) (S49R) beta (2) (E6V) ) that exhibited normal O(2) affinity and co-operatively at pH 7.4. Allosteric effectors, 2,3-DPG, L35, and NaCl increased O(2) 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 alpha-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 alpha-chains and gene therapy of sickle cell anemia.
ISSN:1572-3887
1875-8355
DOI:10.1007/s10930-007-9089-9