Cross-linking with O-raffinose lowers oxygen affinity and stabilizes haemoglobin in a non-cooperative T-state conformation

2005 ◽  
Vol 385 (3) ◽  
pp. 839-839
Author(s):  
Y. JIA ◽  
S. RAMASAMY ◽  
F. WOOD ◽  
A. I. ALAYASH ◽  
J. M. RIFKIND
Keyword(s):  
Oxygen Affinity ◽  
Cross Linking ◽  
T State

scholarly journals Cross-linking with O-raffinose lowers oxygen affinity and stabilizes haemoglobin in a non-cooperative T-state conformation

2004 ◽  
Vol 384 (2) ◽  
pp. 367-375 ◽  
Author(s):  
Yiping JIA ◽  
Somasundaram RAMASAMY ◽  
Francine WOOD ◽  
Abdu I. ALAYASH ◽  
Joseph M. RIFKIND
Keyword(s):  
Hyperfine Splitting ◽  
Oxygen Affinity ◽  
Thiol Group ◽  
Cross Linking ◽  
Native Protein ◽  
Epr Spectrum ◽  
Human Haemoglobin ◽  
Lower Oxygen ◽  
T State ◽  
Kinetics Of

O-R-polyHbA0 is an intra- and intermolecularly O-raffinose cross-linked derivative of deoxygenated human haemoglobin developed as an oxygen therapeutic. When compared with its native protein (HbA0), O-R-polyHbA0 was found to be locked in the T (tense) quaternary conformation with a lower oxygen affinity, a reduced Bohr effect (50% of HbA0) and no measurable cooperativity (h=1). The kinetics of oxygen and CO binding to the protein indicate lower ‘on’ rates and faster ‘off’ rates than HbA0 and the absence of effects of inositol hexaphosphate (IHP) on the kinetics. Other properties consistent with a T-like conformation are inaccessibility of the βCys-93 thiol group of O-R-polyHbA0, the hyperfine splitting from nitrogen in the EPR spectrum of the Fe(II)NO complex of O-R-polyHbA0 and decreased flexibility in the distal haem pocket, as indicated by low-spin bis-histidine complexes detected by EPR of oxidized chains. A comparison of the properties of O-R-polyHbA0 with those of HbA0 with and without IHP, as well as the reaction of nitrite with deoxygenated haemoglobin, provide additional insights into the variations in the conformation of T-state haemoglobin in solution (modifications of the T state produced by adding organic phosphates, like IHP and 2,3-diphosphoglycerate). Although the physiological ramifications of locking HbA0 in the T conformation with the O-raffinose are still unknown, valuable insights into haemoglobin function are provided by these studies of O-R-polyHbA0.

scholarly journals Familial secondary erythrocytosis due to increased oxygen affinity is caused by destabilization of the T state of hemoglobin Brigham (α2β2Pro100Leu)

2012 ◽  
Vol 21 (10) ◽  
pp. 1444-1455 ◽  
Author(s):  
Todd L. Mollan ◽  
Bindu Abraham ◽  
Michael Brad Strader ◽  
Yiping Jia ◽  
Jay N. Lozier ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
T State

Glutaraldehyde effect on hemoglobin: evidence for an ion environment modification based on electron paramagnetic resonance and Mossbauer spectroscopies

1990 ◽  
Vol 68 (4) ◽  
pp. 813-818 ◽  
Author(s):  
Alain Chevalier ◽  
Didiers Guillochon ◽  
Naima Nedjar ◽  
Jean Marie Piot ◽  
Mokambes Waran Vijayalakshmi ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Functional Properties ◽  
Oxygen Affinity ◽  
Blood Substitute ◽  
Blood Substitutes ◽  
Point Of View ◽  
Cross Linking ◽  
Redox Potentials ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

Glutaraldehyde is a widely used reagent for hemoglobin cross-linking in blood substitutes research. However, hemoglobin polymerization by glutaraldehyde involves modifications of its functional properties, such as oxygen affinity, redox potentials, and autoxidation kinetics. The aim of this article is to investigate, by electron paramagnetic resonance and Mossbauer spectroscopies, the changes that occur in the iron environment after glutaraldehyde cross-linking. Spectrometric studies were performed with native hemoglobin and hemoglobin cross-linked as soluble and insoluble polymers. Spectrometry data comparison with glutaraldehyde-modified hemoglobin functional properties allows to interpret from a structural point of view that glutaraldehyde action occurs as a decrease of the O—N(F8His) distance, an increase of the Fe—N(F8His) bond length, and the decrease of the distal-side steric hindrance.Key words: hemoglobin, glutaraldehyde, Mossbauer spectroscopy, electron paramagnetic resonance, blood substitute.

Structure and Oxygen Affinity of Crystalline of DesArg141α Human Hemoglobin A in the T State

1995 ◽  
Vol 248 (1) ◽  
pp. 136-150 ◽  
Author(s):  
Jeffrey S. Kavanaugh ◽  
David R. Chafin ◽  
Arthur Arnone ◽  
Andrea Mozzarelli ◽  
Claudio Rivetti ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
Human Hemoglobin ◽  
Hemoglobin A ◽  
T State

Engineering oxidative stability in human hemoglobin based on the Hb providence (βK82D) mutation and genetic cross-linking

2017 ◽  
Vol 474 (24) ◽  
pp. 4171-4192 ◽  
Author(s):  
Michael Brad Strader ◽  
Rachel Bangle ◽  
Claire J. Parker Siburt ◽  
Cornelius L. Varnado ◽  
Jayashree Soman ◽  
...  
Keyword(s):  
Oxidative Degradation ◽  
Oxygen Affinity ◽  
Side Chain ◽  
Cross Linking ◽  
Critical Element ◽  
Low Oxygen ◽  
Naturally Occurring ◽  
Low Concentrations ◽  
Genetic Cross ◽  
Low Oxygen Affinity

Previous work suggested that hemoglobin (Hb) tetramer formation slows autoxidation and hemin loss and that the naturally occurring mutant, Hb Providence (HbProv; βK82D), is much more resistant to degradation by H2O2. We have examined systematically the effects of genetic cross-linking of Hb tetramers with and without the HbProv mutation on autoxidation, hemin loss, and reactions with H2O2, using native HbA and various wild-type recombinant Hbs as controls. Genetically cross-linked Hb Presbyterian (βN108K) was also examined as an example of a low oxygen affinity tetramer. Our conclusions are: (a) at low concentrations, all the cross-linked tetramers show smaller rates of autoxidation and hemin loss than HbA, which can dissociate into much less stable dimers and (b) the HbProv βK82D mutation confers more resistance to degradation by H2O2, by markedly inhibiting oxidation of the β93 cysteine side chain, particularly in cross-linked tetramers and even in the presence of the destabilizing Hb Presbyterian mutation. These results show that cross-linking and the βK82D mutation do enhance the resistance of Hb to oxidative degradation, a critical element in the design of a safe and effective oxygen therapeutic.

scholarly journals Structure and Oxygen Affinity of Crystalline des-His-146β Human Hemoglobin in the T State

1997 ◽  
Vol 272 (52) ◽  
pp. 33077-33084 ◽  
Author(s):  
Stefano Bettati ◽  
Laura D. Kwiatkowski ◽  
Jeffrey S. Kavanaugh ◽  
Andrea Mozzarelli ◽  
Arthur Arnone ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
Human Hemoglobin ◽  
T State

Structures of R- and T-state hemoglobin Bassett: elucidating the structural basis for the low oxygen affinity of a mutant hemoglobin

2005 ◽  
Vol 61 (2) ◽  
pp. 156-162 ◽  
Author(s):  
Martin K. Safo ◽  
Osheiza Abdulmalik ◽  
Hsiang-Ru Lin ◽  
Toshio Asakura ◽  
Donald J. Abraham
Keyword(s):  
Oxygen Affinity ◽  
Structural Basis ◽  
Low Oxygen ◽  
T State ◽  
Low Oxygen Affinity

scholarly journals Influence of intramolecular cross-links on the molecular, structural and functional properties of PEGylated haemoglobin

2007 ◽  
Vol 402 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Tao Hu ◽  
Belur N. Manjula ◽  
Dongxia Li ◽  
Michael Brenowitz ◽  
Seetharama A. Acharya
Keyword(s):  
Functional Properties ◽  
Oxygen Affinity ◽  
Direct Consequence ◽  
Molecular Properties ◽  
Cross Linking ◽  
Hydrodynamic Drag ◽  
Cross Link ◽  
Central Cavity ◽  
Structural And Functional Properties ◽  
Cross Links

The influence of intramolecular cross-links on the molecular, structural and functional properties of PEGylated {PEG [poly(ethylene glycol)]-conjugated} haemoglobin has been investigated. The sites and the extent of PEGylation of haemoglobin by reductive alkylation are not influenced by the presence of an αα-fumaryl cross-link at Lys-99(α). The propylated hexaPEGylated cross-linked haemoglobin, (propyl-PEG5K)6-αα-Hb, exhibits a larger molecular radius and lower colloidal osmotic pressure than propylated hexaPEGylated non-cross-linked haemoglobin, (propyl-PEG5K)6-Hb. Perturbation of the haem microenvironment and the α1β2 interface by PEGylation of haemoglobin is reduced by intramolecular cross-linking. Sedimentation velocity analysis established that PEGylation destabilizes the tetrameric structure of haemoglobin. (Propyl-PEG5K)6-Hb and (propyl-PEG5K)6-αα-Hb sediment as stable dimeric and tetrameric molecules, respectively. The ββ-succinimidophenyl PEG-2000 cross-link at Cys-93(β) outside the central cavity also influences the molecular properties of haemoglobin, comparable to that by the αα-fumaryl cross-link within the central cavity. However, the influence of the two cross-links on the oxygen affinity of PEGylated haemoglobin are very distinct, indicating that the high oxygen affinity of PEGylated haemoglobin is not a direct consequence of the dissociation of the haemoglobin tetramers into dimers. αα-Fumaryl cross-linking is preferred to modulate both oxygen affinity and molecular properties of PEGylated haemoglobin, and cross-linking outside the central cavity could only modulate molecular properties of PEGylated haemoglobin. It is suggested that PEGylation induces a hydrodynamic drag on haemoglobin and this plays a role in the microcirculatory properties of PEGylated haemoglobin.

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