Hemoglobin spacing in erythrocytes

Bateman, J; Hsu, Shi-Ling; Knudsen, J.P.; Yudowitch, K. L.

doi:10.1016/s0003-9861(53)80017-2

Cited by 18 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Hb molecules in the red cell are packed very tightly. Under isosmolal conditions in human red cells, the Hb molecules are separated by only about 27 A according to Bateman et al (2) and Riley and Herbert (3) as compared to the 15 A separation observed by Perutz (4) in crystalline horse hemoglobin. Tanford (5) computes that the Debye-HUickel electrostatic free energy of an impenetrable spherical protein of 25 A radius would decrease from 6.7 kcal/mole to 2.5 kcal/mole when the ionic strength increases from 0.01 to 0.15 for a net charge of 10 units.…”

Section: Resultsmentioning

confidence: 85%

Hemoglobin Charge Dependence on Hemoglobin Concentration in Vitro

Gary-Bobo

Solomon

1971

The Journal of General Physiology

View full text Add to dashboard Cite

Studies have been made of the dependence of the charge of the hemoglobin molecule on hemoglobin concentration in the concentration range between 3 and 11 mmolal. The charge has been determined by measuring the distribution of 42K between'a hemoglobin solution in a cellophane bag and an external solution. The pHwas 6.6, the K concentration was 10 mM, and the temperature was 4°C. The charge decreased along a sigmoid curve from a value of +3 in the most dilute solutions to a value of +0.5 in the most concentrated solutions. The results were in excellent agreement with earlier studies of Gary-Bobo and Solomon in which Cl distribution was measured between human red cells and external solutions and thus give added support to the conclusion that the apparent anomalous osmotic behavior of human red cells may be attributed to concentration-dependent changes in the hemoglobin net charge. The present findings also support the view that the water in the red cell is solvent water for K and C1 and differs in no quantitatively important respect from bulk water in free solution.The apparent anomalous osmotic behavior of red blood cells has its origin in concentration-dependent effects on hemoglobin (Hb) net charge according to a hypothesis developed by Gary-Bobo and Solomon (1). These authors presented experimental evidence from studies of the human red cell showing that the net charge on the Hb molecule at constant pH decreases with increases in Hb concentration. As a result changes in red cell volume at constant pH affect the Hb charge so that red cell counterion concentration, primarily C1 and HCO 3 , should depend on red cell volume. The quantitative agreement Gary-Bobo and Solomon obtained between experimental and predicted C1 shifts with cell volume changes, in HCO 3 -free human red cells, offered powerful support to the hypothesis of a concentration-dependent cooperative interaction among Hb molecules. These previous observations were all made in whole human red cells in which the interior milieu could 283

show abstract

Section: Resultsmentioning

confidence: 85%

Hemoglobin Charge Dependence on Hemoglobin Concentration in Vitro

Gary-Bobo

Solomon

1971

The Journal of General Physiology

View full text Add to dashboard Cite

show abstract

“…This possibility might be supported by the ease with which hemoglobin-S crystallizes in sickle cells (16). However, Bateman et al (17) indicate from x-ray diffraction studies that the hemoglobin in isotonic human red cells is randomly oriented, and that this orientation persists even when the cells are shrunken in a medium of 0.620 osmolal. Furthermore their diffraction data are in agreement with the results of Riley and Herbert (18) who studied the x-ray diffraction of human hemoglobin in solution over the same concentration range.…”

Section: Discussionmentioning

confidence: 99%

Osmotic Properties of Human Red Cells

Savitz

Sidel

Solomon

1964

The Journal of General Physiology

189

View full text Add to dashboard Cite

A BST R A CT The hematocrit method as a technique for determining red cell volume under anisotonic conditions has been reexamined and has been shown, with appropriate corrections for trapped plasma, to provide a true measure of cell volume. Cell volume changes in response to equilibration in anisotonic media were found to be much less than those predicted for an ideal osmometer; this anomalous behavior cannot be explained by solute leakage or by the changing osmotic coefficient of hemoglobin, but is quantitatively accounted for by the hypothesis that 20 per cent of intracellular water is bound to hemoglobin and is unavailable for participation in osmotic shifts.When the chemical potential of the water surrounding a red cell is altered, the cell responds by a shift in volume. The magnitude of this shift provides important clues concerning the state of solvent and solute within the ceil. Dick and Lowenstein (1) and Hendry (2) have challenged the long standing observation (3) that a portion of the water of red cells does not appear to take part in these osmotic responses. We have therefore reexamined the hematocrit method, on which most of the earlier work had been based, as a method for measuring cell volume. Our results show that this method provides an accurate estimate of cell volume, even under anisotonic conditions, so long as suitable corrections are made for the medium trapped in the cell column. We have also made new measurements of the osmotic behavior of red cells. The change in red cell water content is less than expected on an ideal basis, an observation we have attributed to the layer of water of hydration surrounding the protein, called "bound water" by Perutz (4), rather than to changes in the osmotic coefficient of hemoglobin with protein concentration as suggested by Maizels and McConaghey (5) and others. I. EVALUATION OF THE HEMATOCRIT METHODIn order to evaluate the hematocrit method, it is necessary to compare the results obtained by this technique with volumes determined by an independent procedure. Isotope dilution has been chosen for this purpose, a method which depends only on volume measurements of the total suspension and the medium and therefore is not influenced by the means of separating 79

show abstract

“…These decreases presumably represent changes in the volume of serum lodged between the cells, although it is not known that the hematocrit value, i.e., the packed cell volume, is the same during centrifugation as it is afterward when the measurements are made. It is also known (20) that Hb exists inside the cell in random orientation that persists for small perturbations of cell volume, such as those that took place (Ϯ10%) in the conditions underlying the results presented in Figs. 2 and 3.…”

Section: Resultsmentioning

confidence: 78%