The heme group.
The visible absorption spectra of oxygenated and deoxygenated hemoglobins.
Oxygen dissociation curves of Mb and of Hb in whole blood.
Hill plots for Mb and purified ("stripped") Hb.
A picket-fence Fe(II)porphyrin complex with bound O2 (prevents auto-oxidation via dimerization)
Effect of pH on the O2-dissociation curve of Hb: the Bohr effect.
Comparison of the O2-dissociation curves of "stripped" Hb and whole blood in 0.01M NaCl at pH 7.0.
The effects of 2,3-BPG and CO2, both separately and combined, on hemoglobins O2-dissociation curve compared with that of whole blood (red curve).
The effect of high-altitude exposure on the p50 and the BPG concentration of blood in sea leveladapted individuals.
The O2-dissociation curves of blood adapted to sea level (black curve) and to high altitude (red curve).
Structure of sperm whale myoglobin (Mb)
The Amino Acid Sequences of the a and b Chains of Human Hemoglobin and of Human Myoglobin
Stereo drawings of the heme complex in oxyMb.
The X-ray structure of deoxyHb as viewed down its exact 2-fold axes.
The X-ray structure of oxyHb as viewed down its exact 2-fold axes.
The major structural differences between the quaternary conformations of (a) deoxyHb and (b) oxyHb
The heme group and its environment in the unliganded a chain of human Hb.
Triggering mechanism for the T ® R transition in Hb (T = blue; R = pink)
The a1Cb2FG interface of Hb in (a) the T state and (b) the R state.
The hemoglobin a1b2 interface as viewed perpendicularly to Fig. 10-13.
Networks of salt bridges and hydrogen bonds in deoxyHb. (a) Last two residues of the a chains.
Networks of salt bridges and hydrogen bonds in deoxyHb. (b) Last two residues of the b chains.
Free energy and saturation curves for O2 binding to hemoglobin
Reaction of cyanate with the unprotonated (nucleophilic) forms of primary amino groups.
Binding of BPG to deoxyHb: selective stabilization of the T form
Mutations stabilizing the Fe(III) oxidation state of heme. (a) Alterations in the heme pocket of the a subunit on changing from deoxyHbA to Hb Boston.
Mutations stabilizing the Fe(III) oxidation state of heme. (b) The structure of the heme pocket of the b subunit in Hb Milwaukee.
Electron micrograph of deoxyHbS fibers spilling out of a ruptured erythrocyte.
220-Å in diameter fibers of deoxyHbS: an electron micrograph of a negatively stained fiber
220-Å in diameter fibers of deoxyHbS: a model, viewed in cross section, of the HbS fiber.
Structure of the deoxyHbS fiber: arrangement of the deoxyHbS molecules in the fiber.
Structure of the deoxyHbS fiber: a schematic diagram indicating the intermolecular contacts in the crystal structure of deoxyHbS.
Structure of the deoxyHbS fiber: the mutant Val 6b2 fits neatly into a hydrophobic pocket formed mainly by Phe 85 and Leu 88 of an adjacent b1 subunit.
Time course of deoxyHbS gelation: the extent of gelation as monitored calorimetrically (yellow) and optically (purple).
Time course of deoxyHbS gelation: a loglog plot showing the concentration dependence of 1/td for the gelation of deoxyHbS at 30°C.
Double nucleation mechanism for deoxyHbS gelation
The species and reactions permitted under the symmetry model of allosterism
Models of ligand binding
The sequential model of allosterism
Sequential binding of ligand in the sequential model of allosterism
The sequential and the symmetry models of allosterism can provide equally good fits to the measured O2-dissociation curve of Hb.
Free energy penalties for binding O2 to various ligation states of Hb tetramers relative to O2-binding to noncooperative Hb ab dimers.
Adair Constants for Hemoglobin A at pH 7.40.
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