Myoglobin oxygen dissociation by multiwavelength spectroscopy

1997 ◽  
Vol 82 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Kenneth A. Schenkman ◽  
David R. Marble ◽  
David H. Burns ◽  
Eric O. Feigl
Keyword(s):  
Least Squares ◽  
Hill Equation ◽  
Oxygen Binding ◽  
Dissociation Curve ◽  
Nitrogen Gas ◽  
Binding Characteristics ◽  
Oxygen Fraction ◽  
Oxygen Dissociation ◽  
Dissociation Curves ◽  
The Hill

Schenkman, Kenneth A., David R. Marble, David H. Burns, and Eric O. Feigl. Myoglobin oxygen dissociation by multiwavelength spectroscopy. J. Appl. Physiol. 82(1): 86–92, 1997.—Multiwavelength optical spectroscopy was used to determine the oxygen-binding characteristics for equine myoglobin. Oxygen-binding relationships as a function of oxygen tension were determined for temperatures of 10, 25, 35, 37, and 40°C, at pH 7.0. In addition, dissociation curves were determined at 37°C for pH 6.5, 7.0, and 7.5. Equilibration was achieved with a myoglobin solution, at the desired temperature and pH, and 16 oxygen-nitrogen gas mixtures of known oxygen fraction. Correction for the inevitable presence of metmyoglobin was made by using a three-component least squares analysis and by correcting the end point oxymyoglobin spectra for the presence of metmyoglobin. The[Formula: see text] at which myoglobin is half-saturated with O2(P50) was determined to be 2.39 Torr at pH 7.0 and 37°C. The myoglobin dissociation curve was well fit by the Hill equation [saturation =[Formula: see text]/([Formula: see text]+ P50)].

The oxygen dissociation curve of haemoglobin in dilute solution

1936 ◽  
Vol 120 (819) ◽  
pp. 484-495 ◽  
Keyword(s):  
Spectroscopic Method ◽  
Marked Change ◽  
Maternal Blood ◽  
Gas Analysis ◽  
Dilute Solution ◽  
Dissociation Curve ◽  
Foetal Haemoglobin ◽  
Oxygen Dissociation ◽  
Dissociation Curves ◽  
The Relationship

The spectroscopic determination of the oxygen dissociation curves of haemoglobin has an advantage over the tonometer and gas analysis method, in that much smaller quantities of haemoglobin can be made use of. The spectroscopic method was used to determine the relationship between the foetal and maternal haemoglobins in the sheep during a study of foetal respiration made by Barcroft (1935). The conditions for the comparison of the haemoglobins were a dilute solution of the haemoglobin at p H 9·2 (borate buffer) and at 20° C. These conditions were chosen because of the very accurate determinations of the dissociation curves of dilute haemoglobin of the sheep by Forbes and Roughton (1931) and because these authors recommend p H 9·2 at room temperature as most suitable for a study of the oxygen equilibrium of haemoglobin, all the haemoglobin being in the form of the alkali salt. McCarthy (1933) and Hall (1934) had found previously that the haemoglobins of the foetal and maternal goat were different, the foetal haemoglobin (in the blood and as purified haemoglobin) having a higher affinity for oxygen. The same relationship was found to exist in the sheep haemoglobins in dilute solution at 20° C and p H 9·2. When samples of human foetal and maternal blood (sent by Professor Fleming from the Obstetrical Department of the Royal Free Hospital) were compared in dilute solution it was found that the foetal haemoglobin had a lower affinity for oxygen than the maternal. This was also found by Haurowitz (1935) for dilute solutions of the haemoglobins of mother and new born infant. Haurowitz, however, pointed out that in the corpuscles the affinity for oxygen is less in the infant’s haemoglobin than in that of the mother, but the method used by him did not allow of measurements on suspensions of corpuscles. In the present work the dissociation curves of dilute suspensions of corpuscles have been compared with similar solutions of the haemoglobin. It was found that the relationship of the dissociation curves for human foetal and maternal corpuscles is the same as that found by Barcroft in the goat and in the sheep. It has now been found that by a dilution of human adult haemoglobin the dissociation curve is altered by 200% to a position of higher affinity for oxygen, without any marked change in shape. The haemoglobin of the human foetus, on the other hand, is much less affected by dilution, thus explaining the anomaly of the reversed relationship when solutions of the haemoglobins are used instead of suspensions of corpuscles. It was shown by the work of Bock, Field, and Adair (1924), and by Adair (1925), that a solution of haemoglobin free from stromata and of a similar concentration to blood gives a dissociation curve like whole blood. This makes it clear that in the comparison of dilute haemoglobin solutions with suspensions of corpuscles we are concerned, not simply with a change in the haemoglobin due to haemolysis, but a change due to a dilution of the contents of the corpuscle.

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.

An electrolytic method for determining oxygen dissociation curves using small blood samples: the effect of temperature on trout and human blood

1976 ◽  
Vol 65 (1) ◽  
pp. 21-38
Author(s):  
G. M. Hughes ◽  
J. G. O'Neill ◽  
W.J. van Aardt
Keyword(s):  
Human Blood ◽  
Marked Effect ◽  
Effect Of Temperature ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
Fish Blood ◽  
Bohr Factor ◽  
Dissociation Curves ◽  
The Relationship

1. A detailed account is given of an electrolytic method for determining the oxygen dissociation curve of fish blood using a single sample of 50–100 mul for the whole curve. The accuracy and some of the problems arising from its uses are discussed. 2. Oxygen dissociation curves have been determined for trout blood and human blood at temperatures of 15 and 37 degrees C. The relationship between P50 and temperature is similar to that obtained using other methods. Absolute values of P50 are generally lower than those obtained by other methods, especially in the case of fish blood. 3. The effect of PCO2 and pH on the oxygen dissociation curve of trout blood is tested and it is shown that PCO2 has a more marked effect than pH when the other factor is maintained at a constant level. The Bohr factor (delta log P50/delta pH) appears to be approximately the same and independent of the PCO2. 4.The P50 of ray blood determined from fish during and after an operation showed an increased Bohr factor.

Bohr effect and slope of the oxygen dissociation curve after physical training

1982 ◽  
Vol 52 (6) ◽  
pp. 1524-1529 ◽  
Author(s):  
K. M. Braumann ◽  
D. Boning ◽  
F. Trost
Keyword(s):  
Venous Blood ◽  
Training Period ◽  
Dissociation Curve ◽  
Period Increase ◽  
Oxygen Dissociation ◽  
Small Rise ◽  
Dissociation Curves ◽  
O2 Dissociation

Three O2 dissociation curves from venous blood [taken at rest (A), after in vitro acidification with lactic acid (B), and after exhaustive exercise (C)] were determined in eight athletes twice in a year in detrained and fully trained state. The steepness of the standard O2 dissociation curve becomes greater during the training period (increase in Hill's n from 2.68 +/- 0.10 to 2.96 +/- 0.15). There was a concomitant small rise in the intraerythrocytic organic phosphate concentrations. Bohr coefficients (BC) were calculated for blood O2 saturations ranging from 10 to 80% by comparing the dissociation curves A and B (“in vitro” BC) and curves A and C (“in vivo” BC). In detrained and trained state the in vivo BC show their maximal values at low saturation levels, in contrast the in vitro BC exhibit maximal values at middle saturations. During the training period there was an increase in the in vivo BC as well as in the in vitro BC at low saturations. These alterations may lead to augmented O2 extraction from a given volume of blood by up to 15% during heavy work in trained state. The reason for these observations could be an altered erythrocyte population.

Oxygen dissociation curve for chorioallantoic capillary blood of chicken embryo

1976 ◽  
Vol 40 (3) ◽  
pp. 393-398 ◽  
Author(s):  
H. Tazawa ◽  
T. Ono ◽  
M. Mochizuki
Keyword(s):  
Oxygen Affinity ◽  
Capillary Blood ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
Oxygen Capacity ◽  
Bohr Factor ◽  
Hill’S Equations ◽  
Dissociation Curves ◽  
Clear Relation

Oxygen dissociation curves for blood in the chorioallantoic capillary of chicken embryos were determined using a microphotometric apparatus made for measuring the reaction velocity of a red blood cell with oxygen and carbon monoxide. The modified Hill's equations expressing the dissociation curve during development were calculated by two methods. P50's at pH of 7.4 were found to be 60.0, 54.4, 46.2, 33.1, and 28.6 mmHg for 10, 12, 14, 16 and 18 days of incubation, respectively. Although the Bohr factor did not show a clear relation to age, the oxygen affinity and the oxygen capacity tended to increase with the lapse of days, and the power of heme-to-heme interaction, to decrease with age. The findings imply that there is a respiratory adaptation of embryos during development.

scholarly journals Partial oxygen-dissociation of crystalline giant hemoglobin

2014 ◽  
Vol 70 (a1) ◽  
pp. C474-C474 ◽  
Author(s):  
Nobutaka Numoto ◽  
Taro Nakagawa ◽  
Akiko Kita ◽  
Nobutoshi Ito ◽  
Yoshihiro Fukumori ◽  
...  
Keyword(s):  
Structural Changes ◽  
Quaternary Structure ◽  
Oxygen Binding ◽  
Nitrogen Gas ◽  
Soaking Time ◽  
Allosteric Mechanism ◽  
Oxygen Dissociation ◽  
Intermediate States ◽  
Complete Dissociation ◽  
Partial Oxygen

Allosteric oxygen-binding of hemoglobin (Hb) has been widely discussed based on the quaternary structural changes elucidated by the crystal structures of the oxygenated and deoxygenated states. However, it remains to be determined the structure of intermediate states between the oxy and deoxy forms without any artificial modification of the Hb molecule. A tubeworm, Lamellibrachia satsuma has extracellular giant hemoglobins with a molecular mass of about 400 and 3,600 kDa. Recently, we have determined the crystal structure of the 400 kDa Hb (V2Hb) in the oxy state, and then we successfully obtained the deoxygenated crystals of V2Hb from oxy crystals by the soaking methods [1]. These findings encourage us to initiate structural studies for the intermediate states between the oxy and deoxy forms of V2Hb, which should provide a more accurate understanding of the allosteric mechanism of Hbs. The deoxy crystals of V2Hb were obtained from oxy crystals through the soaking in a solution containing 50 mM sodium hydrosulfite, and incubated for a few minutes. We tested various soaking times from 3 s to 180 s and then immediately flash-frozen under a nitrogen gas stream. The obtained structures reveal that in the case of the soaking time was longer than 10 s, the electron densities of the oxygen molecules at some heme pockets (oxygen binding sites) were very week or disappeared. These `intermediate' structures show almost the same quaternary structure as that of the oxy structure. This fact suggests that quaternary rearrangement of V2Hb might arise just before a complete dissociation of all the oxygen molecules from all the subunits.

A mathematical model of the hemoglobin-oxygen dissociation curve of human blood and of the oxygen partial pressure as a function of temperature.

1984 ◽  
Vol 30 (10) ◽  
pp. 1646-1651 ◽  
Author(s):  
O Siggaard-Andersen ◽  
P D Wimberley ◽  
I Göthgen ◽  
M Siggaard-Andersen
Keyword(s):  
Mathematical Model ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Temperature Coefficient ◽  
Inverse Function ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
Hill Slope ◽  
Dissociation Curves

Abstract A mathematical model is described giving the oxygen saturation fraction (s) as a function of the oxygen partial pressure (p): y - y0 = x - x0 + h X tanh [k X (x - x0)], where y = kn[s/(1-s)] and x = ln(p/kPa). The parameters are: y0 = 1.875; x0 = 1.946 + a + b; h = 3.5 + a; k = 0.5343; b = 0.055 X [T/(K - 310.15)]; a = 1.04 X (7.4 - pH) + 0.005 X Cbase/(mmol/L) + 0.07 X [[CDPG/(mmol/L)] - 5], where Cbase is the base excess of the blood and CDPG is the concentration of 2,3-diphosphoglycerate in the erythrocytes. The Hill slope, n = dy/dx, is given by n = 1 + h X k X [1 - tanh2[k X (x - x0)]]. n attains a maximum of 2.87 for x = x0, and n----1 for x----+/- infinity. The model gives a very good fit to the Severinghaus standard oxygen dissociation curve and the parameters may easily be fitted to other oxygen dissociation curves as well. Applications of the model are described including the solution of the inverse function (p as a function of s) by a Newton-Raphson iteration method. The po2-temperature coefficient is given by dlnp/dT = [A X alpha X p + CHb X n X S X (1 - s) X B]/[alpha X p + CHB X n X s X (1 - s)], where A = -dln alpha/dT approximately equal to 0.012 K-1; B = (lnp/T)s = 0.073 K-1 for y = y0; alpha = the solubility coefficient of O2 in blood = 0.0105 mmol X L-1 X kPa-1 at 37 degrees C; CHb = concentration of hemoglobin iron in the blood. Approximate equations currently in use do not take the variations of the po2-temperature coefficient with p50 and CHb into account.

scholarly journals No evidence of hemoglobin damage by SARS-CoV-2 infection

Haematologica ◽  
2020 ◽  
Vol 105 (12) ◽  
pp. 2769-2773 ◽  
Author(s):  
Anthony W. DeMartino ◽  
Jason J. Rose ◽  
Matthew B. Amdahl ◽  
Matthew R. Dent ◽  
Faraaz A. Shah ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Venous Blood ◽  
Blood Gases ◽  
Medical Community ◽  
Dissociation Curve ◽  
Prosthetic Group ◽  
Oxygen Dissociation ◽  
Heme Prosthetic Group ◽  
Dissociation Curves ◽  
Underlying Pathophysiology

SARS-CoV-2 disease (COVID-19) has affected over 22 million patients worldwide as of August 2020. As the medical community seeks better understanding of the underlying pathophysiology of COVID-19, several theories have been proposed. One widely shared theory suggests that SARS-CoV-2 proteins directly interact with human hemoglobin (Hb) and facilitate removal of iron from the heme prosthetic group, leading to the loss of functional hemoglobin and accumulation of iron. Herein, we refute this theory. We compared clinical data from 21 critically ill COVID-19 patients to 21 non-COVID-19 ARDS patient controls, generating hemoglobin-oxygen dissociation curves from venous blood gases. This curve generated from the COVID-19 cohort matched the idealized oxygen-hemoglobin dissociation curve well (Pearson correlation, R2 = 0.97, P<0.0001; CV(RMSD) = 7.3%). We further analyzed hemoglobin, total bilirubin, lactate dehydrogenase, iron, ferritin, and haptoglobin levels. For all analyzed parameters, patients with COVID-19 had similar levels compared to patients with ARDS without COVID-19. These results indicate that patients with COVID-19 do not exhibit any hemolytic anemia or a shift in the normal hemoglobin-oxygen dissociation curve. We therefore conclude that COVID-19 does not impact oxygen delivery through a mechanism involving red cell hemolysis and subsequent removal of iron from the heme prosthetic group in hemoglobin.

The Lack of Effects of Phototherapy on Neonatal Oxygen Dissociation Curves and Hemoglobin Concentration in Vivo

PEDIATRICS ◽  
1977 ◽  
Vol 59 (6) ◽  
pp. 1027-1031
Author(s):  
Barry D. Chandler ◽  
William J. Cashore ◽  
Pierre J. P. Monin ◽  
William Oh
Keyword(s):  
Serum Bilirubin ◽  
Hemoglobin Concentration ◽  
Control Group ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
The Right ◽  
Dissociation Curves ◽  
2,3 Dpg

Phototherapy has been shown to cause hemolysis of fetal red cells and a shift to the right in the neonatal oxygen dissociation curve (ΔP50) in vitro. To determine if these parameters act similarly in vivo, we have studied 16 icteric infants before and after phototherapy and compared them with eight control infants studied at birth and at 3 days of age, measuring the change in P50, 2,3-diphosphoglycerate (2,3-DPG), serum bilirubin, the percent of bilirubin/albumin saturation, and the hemoglobin concentration in the two groups. Following phototherapy, in the icteric infants there was a shift to the right in the O2 dissociation curve of + 1.7 mm Hg, a rise in 2,3-DPG of 2.26 µmol/gm Hb, a fall in serum bilirubin of 4.3 mg/100 ml, a decrease in percent bilirubin/albumin saturation of 12.4%, and a drop in hemoglobin of 1.1 gm/100 ml. The control group showed a ΔP50 of + 2.0 mm Hg, a rise in 2,3-DPG of 3.67 µmol/gm Hb, an increase in serum bilirubin of 3.2 mg/100 ml, an increase in percent bilirubin/albumin saturation of 9.3%, and a fall in hemoglobin of 0.3 gm/100 ml. Significant differences between the groups were seen only in the changes in bilirubin concentration and percent bilirubin/albunmin saturation. The magnitude of changes in P50, 2,3-DPG, and hemoglobin concentration was similar in the phototherapy and control groups and was related to the expected changes with reference to postnatal age. These results suggest that phototherapy in vivo neither affects fetal erythrocytic affinity for oxygen nor causes hemolysis.

Effect of carbon monoxide on equilibrium between oxygen and hemoglobin

1976 ◽  
Vol 230 (2) ◽  
pp. 471-475 ◽  
Author(s):  
Y Okada ◽  
I Tyuma ◽  
Y Ueda ◽  
T Sugimoto
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Saturation ◽  
Whole Blood ◽  
Oxygen Affinity ◽  
Hill Coefficient ◽  
Human Whole Blood ◽  
Oxygen Dissociation ◽  
Dissociation Curves ◽  
The Hill ◽  
Good Agreement

Oxygen dissociation curves of partially CO-saturated human whole blood drawn freshly or preserved more than 3 wk were studied. With increasing CO-hemoglobin concentrations, oxygen affinity of the blood increased and the Hill coefficient, n, fell and gradually approached unity. The changes induced by CO-hemoglobin showed practically no difference in the presence or absence of 2,3-diphosphoglycerate. The Bohr coefficient, deltalog P50/deltapH, was determined as a function of oxygen saturation for various concentrations of CO-hemoglobin. The coefficient remained essentially unchanged in the presence of CO-hemoglobin. In the presence of less than 50% CO-hemoglobin, a good agreement was observed between the observed oxygen dissociation curves and the curves calculated according to Roughton and Darling (Am. J. Physiol. 141: 17-31, 1944). Based on these results, physiological implications of carboxyhemoglobinemia are discussed quantitatively in comparison with methemoglobinemia.

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