Bohr effect and oxygen affinity of carp, eel and human hemoglobin: Quantitative analyses provide rationale for the Root effect

2018 ◽  
Vol 242 ◽  
pp. 45-59 ◽  
Author(s):  
Kehinde Onwochei Okonjo
Keyword(s):  
Oxygen Affinity ◽  
Bohr Effect ◽  
Human Hemoglobin ◽  
Root Effect ◽  
Quantitative Analyses

scholarly journals Chloride ion independence of the Bohr effect in a mutant human hemoglobin beta (V1M+H2deleted).

1994 ◽  
Vol 269 (39) ◽  
pp. 23965-23969
Author(s):  
C. Fronticelli ◽  
I. Pechik ◽  
W.S. Brinigar ◽  
J. Kowalczyk ◽  
G.L. Gilliland
Keyword(s):  
Chloride Ion ◽  
Bohr Effect ◽  
Human Hemoglobin

Bohr effect of human hemoglobin A: Magnitude of negative contributions determined by the equilibrium between two tertiary structures

2014 ◽  
Vol 190-191 ◽  
pp. 41-49 ◽  
Author(s):  
Kehinde O. Okonjo ◽  
Abimbola M. Olatunde ◽  
Adedayo A. Fodeke ◽  
J. Oyebamiji Babalola
Keyword(s):  
Bohr Effect ◽  
Human Hemoglobin ◽  
Tertiary Structures ◽  
Hemoglobin A

Influence of carbon monoxide on hemoglobin-oxygen binding

1976 ◽  
Vol 41 (6) ◽  
pp. 893-899 ◽  
Author(s):  
M. P. Hlastala ◽  
H. P. McKenna ◽  
R. L. Franada ◽  
J. C. Detter
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Affinity ◽  
Co2 Concentration ◽  
Bohr Effect ◽  
Oxygen Binding ◽  
Dissociation Curve ◽  
Low Oxygen ◽  
Oxygen Dissociation ◽  
Initial Binding ◽  
Fixed Acid

The oxygen dissociation curve and Bohr effect were measured in normal whole blood as a function of carboxyhemoglobin concentration [HbCO]. pH was changed by varying CO2 concentration (CO2 Bohr effect) or by addition of isotonic NaOH or HCl at constant PCO2 (fixed acid Bohr effect). As [HbCO] varied through the range of 2, 25, 50, and 75%, P50 was 26.3, 18.0, 11.6, and 6.5 mmHg, respectively. CO2 Bohr effect was highest at low oxygen saturations. This effect did not change as [HbCO] was increased. However, as [HbCO] was increased from 2 to 75%, the fixed acid Bohr factor increased in magnitude from -0.20 to -0.80 at very low oxygen saturations. The effect of molecular CO2 binding (carbamino) on oxygen affinity was eliminated at high [HbCO]. These results are consistent with the initial binding of O2 or CO to thealpha-chain of hemoglobin. The results also suggest that heme-heme interaction is different for oxygen than for carbon monoxide.

Oxygen-linked CO2 transport in sheep blood

1975 ◽  
Vol 229 (2) ◽  
pp. 334-339 ◽  
Author(s):  
R Bauman ◽  
C Bauer ◽  
EA Haller
Keyword(s):  
Whole Blood ◽  
Oxygen Affinity ◽  
Hemoglobin Concentration ◽  
Cell Suspensions ◽  
Bohr Effect ◽  
Carbon Dioxide Exchange ◽  
Red Cell ◽  
Sheep Blood ◽  
Sheep Hemoglobin ◽  
Binding Curves

We have analyzed oxygen-linked carbamate formation in sheep hemoglobin B by measuring a) the effect of CO2 on oxygen affinity and Bohr effect in red cell suspensions and dilute (1.3 mM Hb4) and concentrated (5 mM Hb4) hemoglobin solutions at 37 degrees C and b) CO2 binding curves of deoxygenated and oxygenated whole blood and hemoglobin solutions, respectively, at the same temperature. In the presence of CO2 both the Bohr effect and oxygen affinity were significantly lower in 1.3-mM Hb4 solutions than in either red cell suspensions or 5-mM Hb4 solutions, while in the absence of CO2 Bohr effect and oxygen affinity did not differ significantly in those preparations. Likewise, the fraction of oxygen-linked carbamate obtained from CO2 binding curves was found to be higher in 1.3-mM Hb4 (0.156 M HbCO2/M HbO2) solutions than in 5-mM Hb4 solutions (0.12 M HbCO2/M HbO2) at pH 7.2. We conclude that hemoglobin concentration affects formation of oxygen-linked carbamate. Total oxygen-linked CO2 in sheep whole blood amounted to 0.18 M CO2/M O2 of which 70% is oxygen-linked carbamate. Assuming a respiratory quotient of 0.85, the contribution of oxygen-linked CO2 to carbon dioxide exchange in sheep blood was computed to be 21%.

scholarly journals THE EFFECT OF FORMALDEHYDE ON THE OXYGEN EQUILIBRIUM OF HEMOGLOBIN

1954 ◽  
Vol 37 (6) ◽  
pp. 775-780 ◽  
Author(s):  
Karl F. Guthe
Keyword(s):  
Oxygen Pressure ◽  
Oxygen Affinity ◽  
Sulfhydryl Groups ◽  
Human Hemoglobin ◽  
Hill’S Equation ◽  
Oxygen Equilibrium ◽  
Hill's Equation ◽  
Hemoglobin Molecule

1. When formaldehyde (0.10 M) is added to solutions of human hemoglobin, the oxygen affinity of the hemoglobin increases considerably (more than tenfold near pH 7). The interaction between hemes of the same hemoglobin molecule decreases, as shown by a drop in the value of n in Hill's equation from 2.9 to 1.5 or less. 2. In the presence of formaldehyde, both n and the oxygen pressure for half-saturation fall gradually as the pH rises in the range from pH 6.2 to 7.2. 3. Some of the effect of formaldehyde on the oxygen equilibrium may be due to combination with sulfhydryl groups of the protein, but nitrogenous groups are probably also involved.

Symmetric interspecies hybrids of mouse and human hemoglobin: Molecular basis of their abnormal oxygen affinity

1995 ◽  
Vol 14 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Rajendra Prasad Roy ◽  
Parimala Nacharaju ◽  
Ronald L. Nagel ◽  
A. Seetharama Acharya
Keyword(s):  
Molecular Basis ◽  
Oxygen Affinity ◽  
Human Hemoglobin ◽  
Interspecies Hybrids
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