Conformational and functional properties of hemoglobin in water-organic cosolvent mixtures: Effect of ethylene glycol and glycerol on oxygen affinity

Biopolymers ◽  
1983 ◽  
Vol 22 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Donatella Bulone ◽  
Antonio Cupane ◽  
Lorenzo Cordone
Keyword(s):  
Ethylene Glycol ◽  
Functional Properties ◽  
Oxygen Affinity ◽  
Organic Cosolvent ◽  
Cosolvent Mixtures

scholarly journals Adult and fetal haemoglobin J-Sardegna [α50(CE8)His→Asp]: functional and molecular modelling studies

2000 ◽  
Vol 346 (1) ◽  
pp. 193-199 ◽  
Author(s):  
Marcella CORDA ◽  
Maria C. DE ROSA ◽  
Maria G. PELLEGRINI ◽  
Maria T. SANNA ◽  
Alessandra OLIANAS ◽  
...  
Keyword(s):  
Functional Properties ◽  
Computational Modelling ◽  
Oxygen Affinity ◽  
Oxygen Binding ◽  
Structural Level ◽  
Fetal Haemoglobin ◽  
Significant Difference ◽  
Molecular Modelling Studies ◽  
Modelling Studies ◽  
2,3 Dpg

Haemoglobin (Hb) J-Sardegna [α50(CE8)His → Asp] is a haemoglobin variant characteristic of subjects from the island of Sardinia. Here we report a study of the functional properties of both fetal and adult Hb J-Sardegna. The results indicate that adult Hb J-Sardegna displays an oxygen affinity that is higher than that of adult Hb only in the presence of 2,3-diphosphoglycerate (2,3-DPG). On the contrary, at 20 °C, the oxygen affinity of fetal Hb J-Sardegna is identical to that of normal fetal haemoglobin, both in the presence and in the absence of 2,3-DPG. A significant difference between these two systems (i.e. a higher oxygen affinity of fetal Hb J-Sardegna) shows up very clearly only when temperature is increased to 37 °C. Hence in fetal Hb, the main effect of the amino acid substitution is a decrease in the overall enthalpy change of oxygenation. The results outline the role of the α1-β1 interface in assessing the thermodynamics of oxygen binding. The functional properties of both adult and fetal Hb J-Sardegna have been interpreted at the structural level in light of the results obtained by a computational modelling approach performed in comparison with HbA and Hb Aichi, a variant characterized by a different mutation [α50(CE8)His → Arg] at the same position.

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.

Abnormal functional properties of Hb hope αCA2β2(H14) Gly → Asp: A low oxygen affinity hemoglobin with decreased DPG effect

FEBS Letters ◽  
1974 ◽  
Vol 47 (1) ◽  
pp. 47-52 ◽  
Author(s):  
J. Thillet ◽  
J. Caburi ◽  
B. Brun ◽  
M. Cohen-Solal ◽  
M.C. Garel ◽  
...  
Keyword(s):  
Functional Properties ◽  
Oxygen Affinity ◽  
Low Oxygen ◽  
Low Oxygen Affinity

scholarly journals Structural and functional effects of selective chemical modifications of Scapharca inaequivalvis haemoglobins in relation to their unique assembly

1987 ◽  
Vol 241 (2) ◽  
pp. 499-504 ◽  
Author(s):  
A Boffi ◽  
M Gattoni ◽  
R Santucci ◽  
P Vecchini ◽  
F Ascoli ◽  
...  
Keyword(s):  
Functional Properties ◽  
Oxygen Affinity ◽  
Thiol Group ◽  
Cysteine Residue ◽  
Oxygen Binding ◽  
Thiol Groups ◽  
Functional Roles ◽  
Dimeric Unit ◽  
Structural And Functional Properties ◽  
Thiol Reagent

The structural and functional roles of lysyl and thiol groups in the dimeric (HbI) and tetrameric (HbII) haemoglobins from the mollusc Scapharca inaequivalvis have been assessed. In these haemoglobins a unique mode of assembly (the haem-carrying E and F helices form the intersubunit contact of the dimeric unit) is associated with co-operative oxygen binding. Extensive acylation is accompanied by significant haem oxidation. Modification of one or two lysyl residues per chain (corresponding to approximately 20% of the total residues) does not affect the structural and functional properties of both haemoglobins, in line with the proposal that the intersubunit contacts are rich in hydrophobic residues. The modification of the thiol groups does not influence the state of association in both HbI and HbII, despite the location of the cysteine residue common to all polypeptide chains in the vicinity of the major intersubunit contact. The effect on the functional properties depends on the size of the thiol reagent: p-chloromercuribenzoate and phenylmercuric acetate increase the oxygen affinity about 20-fold, but iodoacetamide and mercuric chloride have no effect. Moreover, electrophoresis experiments indicate that p-chloromercuribenzoate is bound in a co-operative fashion, the degree of co-operativity being much higher in the dimeric HbI. Thus, only in HbII are intermediates containing substoichiometric amounts of p-chloromercuribenzoate formed in significant amounts. Their oxygen binding properties show that reaction of only one thiol group/tetramer suffices to alter the oxygen affinity of the molecule.

Single Ionic Volumes in Acetonitrile–Organic Cosolvent Mixtures at 298.15 K

2004 ◽  
Vol 218 (6-2004) ◽  
pp. 679-698 ◽  
Author(s):  
Henryk Piekarski ◽  
Alina Piekarska ◽  
Kinga Kubalczyk
Keyword(s):  
Ionic Volumes ◽  
Organic Cosolvent ◽  
Cosolvent Mixtures

scholarly journals Net charge and oxygen affinity of human hemoglobin are independent of hemoglobin concentration.

1978 ◽  
Vol 72 (6) ◽  
pp. 765-773 ◽  
Author(s):  
G Gros ◽  
H S Rollema ◽  
W Jelkmann ◽  
H Gros ◽  
C Bauer ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Functional Properties ◽  
Ph Value ◽  
Oxygen Affinity ◽  
Hemoglobin Concentration ◽  
Human Hemoglobin ◽  
Hemoglobin Solution ◽  
Net Charge ◽  
Oxygen Concentrations

The dependence of net charge and oxygen affinity of human hemoglobin upon hemoglobin concentration was reinvestigated. In contrast to earlier reports from various laboratories, both functional properties of hemoglobin were found to be independent of hemoglobin concentration. Two findings indicate a concentration-independent net charge of carbonmonoxy hemoglobin at pH 6.6: (A) The pH value of a given carbonmonoty hemoglobin solution remains constant at 6.6 when the hemoglobin concentration is raised from 10 to 40 g/dl, indicating that there is no change in protonation of titratable groups of hemoglobin: (b) the net charge of carbonmonoxy hemoglobin as estimated from the Donnan distribution of 22Na+ shows no dependence on hemoglobin concentration in this concentration range. The oxygen affinity of human hemoglobin was determined from measurements of oxygen concentrations in equilibrated samples using a Lex-O2-Con apparatus (Lexington Instruments, Waltham, Mass.). P50 averaged 11.4 mm Hg at 37 degrees C, pH = 7.2, and ionic strength approximately 0.15. Neither P50 nor Hill's n showed any variation with hemoglobin concentrations increasing from 10 to 40 g/dl.

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