501
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Wiechelman KJ, Fairbanks VF, Ho C. Proton nuclear magnetic resonance studies of hemoglobin Malmö: implications of mutations at homologous positions of the alpha and beta chains. Biochemistry 1976; 15:1414-20. [PMID: 1259945 DOI: 10.1021/bi00652a010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The abnormal human hemoglobin Malmö (beta97FG4 His leads to Gln) has been studied and its properties are compared with those of normal adult hemoglobin A. The data presented here show that the ring-current shifted proton resonances of both HbCO and HbO2 Malmö are very different from the corresponding forms of Hb A. The hyperfine shifted proton resonances of deoxy-Hb Malmö do not differ drastically from those of deoxy-Hb A. This result, together with the finding that the exchangeable proton resonances of the deoxy form of the two hemoglobins are similar, suggests that unliganded Hb Malmö can assume a deoxy-like quaternary structure both in the absence and presence of organic phosphates We have also compared the properties of Hb Malmö with those of Hb Chesapeake (alpha92FG4 Arg leads to Leu). This allows us to study the properties of two abnormal human hemoglobins with mutations at homologous positions of the alpha and beta chains in the three-dimenstional structure of the hemoglobin molecule. Our present results suggest that the mutaion at betaFG4 has its greatest effect on the teritiary structure of the heme pocket of the liganded forms of the hemoglobin while the mutation at alphaFG4 alters the deoxy structure of the hemoglogin molecule but does not alter the teriary structure of the heme pockets of the liganded form of the hemoglobin molecule. Both hemoglobins undergo a transition from the deoxy (T) to the oxy (R) quaternary structure upon ligation. The abnormally high oxygen affinities and low cooperativities of these two hemoglobins must therefore be due to either the structural differences which we have observed and/or to an altered transition between the T and R structures.
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502
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Abstract
High-resoluiton proton nuclear magnetic resonance spectroscopy at 250 MHz has been used to investigate sickle cell hemoglobin. The hyperfine shifted, the ring-current shifted, and the exchangeable proton resonances suggest that the heme environment and the subunit interfaces of the sickle cell hemoglobin molecule are normal. These results suggest that the low oxygen affinity in sickle cell blood is not due to conformational alterations in the heme environment or the subunit interfaces. The C-2 proton resonances of certain histidyl residues can serve as structural probes for the surface conformation of the hemoglobin molecule. Several sharp resonances in sickle cell hemoglobin are shifted upfield from their positions in normal adult hemoglobin. These upfield shifts, which are observed in both oxy and deoxy forms of the molecule under various experimental conditions, suggest that some of the surface residues of sickle cell hemoglobin are altered and they may be in a more hydrophobic environment as compared with that of normal human adult hemoglobin. These differences in surface conformation are pH and ionic strength specific. In particular, upon the addition of organic phosphates to normal and sickle cell hemoglobin samples, the differences in their aromatic proton resonances diminish. These changes in the surface conformation may, in part, be responsible for the abnormal properties of sickle cell hemoglobin.
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503
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Abstract
A tryptophan-requiring strain of Escherichia coli can go through two doublings of optical density after L-tryptophan is replaced in the medium by 4-fluorotryptophan, during which the fluoro analog displaces approximately 75% of the L-tryptophan in cell protein. One doubling occurs in the presence of 5- or 6-fluorotryptophan, with 50-60% replacement of L-tryptophan by analog. When beta-galactosidase is induced at the time of addition of analog, it reaches 60% of the control specific activity in the presence of 4-fluorotryptophan, 10% of normal in the presence of 5- or 6-fluorotryptophan. Lactose permease activity is 35% of the control in the presence of 4- and 6-fluorotryptophan, less than 10% in the presence of 5-fluorotryptophan. D-Lactate dehydrogenase shows a specific activity twice that of the control in the presence of 4-fluorotryptophan, one-half with 5- or 6-fluorotryptophan. Thus fluorotryptophan can be incorporated into proteins and affect their activities, although the nature and magnitude of the effect cannot be predicted for any given enzyme. Such substituted proteins should be useful for the study of protein structure and function by 19F nuclear magnetic resonance and other techniques.
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504
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Fung LW, Ho C, Roth EF, Nagel RL. The alkylation of hemoglobin S by nitrogen mustard. High resolution proton nuclear magnetic resonance studies. J Biol Chem 1975; 250:4786-9. [PMID: 1141230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Sickle cell hemoglobin (Hb S) treated with nitrogen mustard (bis(beta-chloroethyl)methylamine hydrochloride) gives two reaction products, one labile and one stable. After dialysis against buffer solution, the remaining stable product is found to inhibit the polymerization of deoxyhemoglobin S. High resolution proton nuclear magnetic resonance has been used to study the structure and function of this stable product and to investigate the nature of the binding sites of nitrogen mustard to the hemoglobin molecule. The NMR results suggest that the nitrogen mustard treatment of Hb S does not alter the heme environment or the subunit interfaces of the hemoglobin molecule. Moreover, the NMR spectra have also shown that the nitrogen mustard reacts with the beta2 histidines of the hemoglobin molecule and have suggested that several other surface amino acid residues of the hemoglobin molecule are also affected by the nitrogen mustard alkylation. These NMR findings are in good agreement with the data obtained from biochemical studies of nitrogen mustard-treated Hb S. The NMR spectra also indicate that nornitrogen mustard (which is also effective in inhibiting sickling) binds with the hemoglobin molecule in a manner identical with nitrogen mustard. Sulfur mustard, on the other hand, produces no observable changes in the aromatic proton resonances, which is consistent with the fact that it does not inhibit the polymerization of deoxy-Hb S.
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505
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Abstract
Proton nuclear magnetic resonance spectra of human hemoglobins in water reveal several exchangeable protons which are indicators of the quaternary structures of both the liganded and unliganded molecules. A comparison of the spectra of normal human adult hemoglobin with those of mutant hemoglobins Chesapeake (FG4alpha92 Arg yields Leu), Titusville (G1alpha94 Asp yields Asn), M Milwaukee (E11beta67 Val yields Glu), Malmo (FG4beta97 His yields Gln), Kempsey (G1beta99 Asp yields Asn), Yakima (G1beta99 Asp yields His), and New York (G15beta113 Val yields Glu), as well as with those of chemically modified hemoglobins Des-Arg(alpha141), Des-His(beta146), NES (on Cys-beta93)-Des-Arg(alpha141), and spin-labeled hemoglobin [Cys-beta93 reacted with N-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)iodoacetamide], suggests that the proton in the important hydrogen bond between the tyrosine at C7alpha42 and the aspartic acid at G1beta99, which anchors the alpha1beta2 subunits of deoxyhemoglobin (a characteristic feature of the deoxy quaternary structure), is responsible for the resonance at -9.4 ppm from water at 27 degrees. Another exchangeable proton resonance which occurs at -6.4 ppm from H2O is a spectroscopic indicator of the deoxy structure. A resonance at -5.8 ppm from H2O, which is an indicator of the oxy conformation, is believed to originate from the hydrogen bond between the aspartic acid at G1alpha94 and the asparagine at G4beta102 in the alpha1beta2 subunit interface (a characteristic feature of the oxy quaternary structure). In the spectrum of methemoglobin at pH 6.2 both the -6.4- and the -5.8ppm resonances are present but not the -9.4-ppm resonance. Upon the addition of inositol hexaphosphate to methemoglobin at pH 6.2, the usual resonance at -9.4 ppm is shifted to -10 ppm and the resonance at 6.4 ppm is not observed. In the spectrum of methemoglobin at pH greater than or equal to 7.6 with or without inositol hexaphosphate, the resonance at -5.8 ppm is present, but not those at -10 and -6.4 ppm, suggesting that methemoglobin at high pH has an oxy-like structure. Two resonances (at -8.2 and -7.3 ppm) which remain invariant in the two quaternary structures could come from exchangeable protons in the alpha1beta1 subunit interface and/or other exchangeable protons in the hemoglobin molecule which undergo no conformational changes during the oxygenation process. These exchangeable proton resonances serve as excellent spectroscopic probes of the quaternary structures of the subunit interfaces in studies of the molecular mechanism of cooperative ligand binding to hemoglobin.
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506
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Fung LW, Ho C, Roth EF, Nagel RL. The alkylation of hemoglobin S by nitrogen mustard. High resolution proton nuclear magnetic resonance studies. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41372-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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507
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Baldassare JJ, Robertson DE, McAfee AG, Ho C. A spin-label study of energy-coupled active transport in Escherichia coli membrane vesicles. Biochemistry 1974; 13:5210-4. [PMID: 4373033 DOI: 10.1021/bi00722a025] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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508
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Ho C. Modulation of hemoglobin function by small molecules. Ann N Y Acad Sci 1974; 241:545-8. [PMID: 4530678 DOI: 10.1111/j.1749-6632.1974.tb21910.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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509
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510
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511
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512
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513
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Perutz MF, Heidner EJ, Ladner JE, Beetlestone JG, Ho C, Slade EF. Influence of globin structure on the state of the heme. 3. Changes in heme spectra accompanying allosteric transitions in methemoglobin and their implications for heme-heme interaction. Biochemistry 1974; 13:2187-200. [PMID: 4363756 DOI: 10.1021/bi00707a028] [Citation(s) in RCA: 164] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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514
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515
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516
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Ho C, Lindstrom TR, Baldassare JJ, Breen JJ. Magnetic resonance studies of human hemoglobins and their implications to the structure-function relationships in human normal and abnormal hemoglobins. Ann N Y Acad Sci 1973; 222:21-39. [PMID: 4361855 DOI: 10.1111/j.1749-6632.1973.tb15250.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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517
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Abstract
By using the lattice statistical argument, we have shown that for a protein whose subunits have the same number of neighbors, the three parameters (K(AB), K(BB), and K(S)K(t)) in the sequential theory formulated by Koshland, Nemethy, and Filmer [Biochemistry (1966) 5, 365] can be reduced to two parameters. One of the parameters, Z, measures the strength of the subunit interactions and is related to the apparent free energy of interaction (DeltaF degrees I) by Z = exp (-DeltaF degrees I/2mkT), where m is the number of neighbors in a subunit and kT has the usual meaning. In addition, we relate Wyman's allosteric binding potential [Advan. Protein Chem. (1964) 19, 223] to the canonical partition function of the McMillan-Mayer theory [J. Chem. Phys. (1945) 13, 276]. An explicit form relating the apparent free energy of interaction and the Hill coefficient is given for an allosteric protein that has nonequivalent and independent ligand-binding sites. The present formulation can be used to account for a number of recent experimental results on hemoglobins.
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518
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519
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Haller JA, Shaker IJ, Gingell R, Ho C. Intrauterine production of coarctation of the aorta. Studies of hemodynamics and collateral aortic circulation in newborn animals. J Thorac Cardiovasc Surg 1973; 66:343-9. [PMID: 4733512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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520
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521
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Kreishman GP, Robertson DE, Ho C. PMR studies of the substrate induced conformational change of glutamine binding protein from E. coli. Biochem Biophys Res Commun 1973; 53:18-23. [PMID: 4582370 DOI: 10.1016/0006-291x(73)91394-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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522
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Abstract
Proton nuclear magnetic resonance spectra of normal and des-(his 146beta) human hemoglobin in the aromatic resonance region have been compared at different pH values. From these measurements, a pK value for histidine 146beta of 7.1 in carbonmonoxyhemoglobin and 8.0 in deoxyhemoglobin has been found. These pK values confirm the proposed role of histidine 146beta in the alkaline Bohr effect.
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523
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Lindstrom TR, Ho C. Effects of anions and ligands on the tertiary structure around ligand binding site in human adult hemoglobin. Biochemistry 1973; 12:134-9. [PMID: 4683478 DOI: 10.1021/bi00725a022] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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524
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Abstract
Nuclear magnetic resonance studies of the contact-shifted spectra of heme protons in deoxyhemoglobin A from human adults show conclusively that oxygen binds to the alpha hemes in preference to the beta hemes. The preferential binding is produced in 10% hemoglobin solution at neutral pH by either a 15-fold molar excess of 2,3-diphosphoglycerate or a 5-fold molar excess of inositol hexaphosphate. Preferential binding is not observable in the absence of the organic phosphates. The results indicate that the oxygenation of hemoglobin may be described by a sequential model, or by a concerted model that allows the alpha hemes to bind ligand first.
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525
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526
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Lindstrom TR, Norén IB, Charache S, Lehmann H, Ho C. Nuclear magnetic resonance studies of hemoglobins. VII. Tertiary structure around ligand binding site in carbonmonoxyhemoglobin. Biochemistry 1972; 11:1677-81. [PMID: 5063711 DOI: 10.1021/bi00759a023] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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527
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528
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Linstrom TR, Olson JS, Mock NH, Gibson QH, Ho C. Nuclear magnetic resonance studies of hemoglobins. 8. Evidence for preferential ligand binding to chains within deoxyhemoglobins. Biochem Biophys Res Commun 1971; 45:22-6. [PMID: 5139924 DOI: 10.1016/0006-291x(71)90044-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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529
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Davis DG, Lindstrom TR, Mock NH, Baldassare JJ, Charache S, Jones RT, Ho C. Nuclear magnetic resonance studies of hemoglobins. VI. Heme proton spectra of human deoxyhemoglobins and their relevance to the nature of co-operative oxygenation of hemoglobin. J Mol Biol 1971; 60:101-11. [PMID: 5572098 DOI: 10.1016/0022-2836(71)90450-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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530
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Norén IB, Ho C, Casassa EF. A light-scattering study of the effect of sodium chloride on the molecular weight of human adult hemoglobin. Biochemistry 1971; 10:3222-9. [PMID: 5119247 DOI: 10.1021/bi00793a010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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531
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532
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Breed JE, Ho C, Breed DS. Titanium as an encasement for cobalt 60 with special reference to a pneumatic afterloading therapy unit. Am J Roentgenol Radium Ther Nucl Med 1971; 111:401-4. [PMID: 5541682 DOI: 10.2214/ajr.111.2.401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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533
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Baldassare JJ, Charache S, Jones RT, Ho C. Electron paramagnetic resonance studies of spin-labeled hemoglobins. II. Roles of subunit interactions and of intermediate structures in the cooperative oxygenation of hemoglobin and the results of hemoglobin Yakima, hemoglobin J capetown, and carboxypeptidases A and B treated hemoglobin A. Biochemistry 1970; 9:4707-13. [PMID: 4320540 DOI: 10.1021/bi00826a013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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534
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Davis DG, Mock NH, Lindstrom TR, Charache S, Ho C. Nuclear magnetic resonance studies of hemoglobiss. V. The heme proton spectra of human deoxyhemoglobins A, F, Zurich, and Chesapeake. Biochem Biophys Res Commun 1970; 40:343-9. [PMID: 5482264 DOI: 10.1016/0006-291x(70)91015-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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535
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Ho C, Baldassare JJ, Charache S. Electron paramagnetic resonance studies of spin-labeled hemoglobins and their implications to the nature of cooperative oxygen binding to hemoglobin. Proc Natl Acad Sci U S A 1970; 66:722-9. [PMID: 4316679 PMCID: PMC283110 DOI: 10.1073/pnas.66.3.722] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The spin label technique has been used to study human hemoglobins A, F, Zürich, and Chesapeake as a function of carbon monoxide saturation. The experimental results suggest that the changes in the electron paramagnetic resonance spectra of hemoglobin labeled with N-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)iodoacetamide depend on the state of ligation of more than one heme group. For those hemoglobins with full or large cooperative ligand binding (such as A, F, and Zürich), there is a lack of isosbestic points in the spectra as a function of CO saturation. However, for those hemoglobins with little or no cooperative ligand binding (such as Chesapeake and methemoglobins), there is a sharp set of isosbestic points. These findings confirm and extend the early work of McConnell and co-workers. The absence of a set of isosbestic points in those hemoglobins with full cooperative ligand binding is consistent with the sequential model of Koshland, Némethy, and Filmer for cooperative oxygen binding to hemoglobin. The present results, with hemoglobin variants having known amino acid substitutions, also focus on the importance of the interactions among the amino acid residues located at alpha(1)-beta(2) or alpha(2)-beta(1) subunit contacts for the functioning of hemoglobin as an oxygen carrier. In addition, the resonance spectra of the spin label are very sensitive to small structural variations around the heme groups in the beta- or gamma-chains where the labels are attached. The results of the spin label experiment are discussed in relation to recent findings on the mechanism of oxygenation of hemoglobin from the nuclear magnetic resonance studies of this laboratory and the x-ray crystallographic analysis of Perutz and co-workers.
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536
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Ho C, Davis DG, Mock NH, Lindstrom TR, Charache S. Nuclear magnetic resonance studies of hemoglobin. IV. The structure-function relationship of human adult hemoglobins A and Chesapeake and its implication to the nature of oxygenation of hemoglobin. Biochem Biophys Res Commun 1970; 38:779-86. [PMID: 5443718 DOI: 10.1016/0006-291x(70)90649-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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537
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538
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Davis DG, Charache S, Ho C. Nuclear magnetic resonance studies of hemoglobins. 3. Evidence for the nonequivalence of alpha- and beta-hains in azide derivativeof methemoglobins. Proc Natl Acad Sci U S A 1969; 63:1403-9. [PMID: 5260944 PMCID: PMC223479 DOI: 10.1073/pnas.63.4.1403] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Nuclear magnetic resonance spectroscopy (100-MHz proton) was used to study the low-spin (S = 1/2) azide derivatives of human adult (alpha(2)beta(2)), human fetal (alpha(2)gamma(2)), Zürich (alpha(2)beta(2) (63 His --> Arg)), and horse (alpha(2)'beta(2)') methemoglobins, as well as whale metmyoglobin in 0.1 M deuterated phosphate at pD 7 and at 31 degrees C. The experimental results indicate that the azide-bound heme groups of the alpha- and beta-chains in human adult methemoglobin and of the alpha- and gamma-chains in fetal methemoglobin are not equivalent. The affinity of the beta- or gamma-chain for azide ion appears larger than that of the alpha-chain. The nuclar magnetic resonance spectrum of hemoglobin Zürich shows that the environment of the azide-heme complex in the abnormal beta-chain is altered by the substitution of arginine for histidine in the beta-63 position, while the alpha-heme environment remains unaffected.
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539
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Ho C, Magnuson JA, Wilson JB, Magnuson NS, Kurland RJ. Phosphorus nuclear magnetic resonance studies of phosphoproteins and phosphorylated molecules. II. Chemical nature of phosphorus atoms in alpha S-casein B and phosvitin. Biochemistry 1969; 8:2074-82. [PMID: 5814938 DOI: 10.1021/bi00833a044] [Citation(s) in RCA: 49] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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540
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541
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Kurland RJ, Davis DG, Ho C. Paramagnetic proton nuclear magnetic resonance shifts of metmyoglobin, methemoglobin, and hemin derivatives. J Am Chem Soc 1968; 90:2700-1. [PMID: 5651073 DOI: 10.1021/ja01012a048] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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542
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Ho C, Chen AH. The polymerization of bovine alpha-s-casein B. J Biol Chem 1967; 242:551-3. [PMID: 6024303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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543
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Ho C, Kurland RJ. Phosphorus nuclear magnetic resonance study of phosphoproteins. I. Chemical nature of phosphorus atoms in bovine alpha-s-casein. J Biol Chem 1966; 241:3002-7. [PMID: 4287904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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544
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Ho C. Studies on malaria in New China. Chin Med J 1965; 84:491-7. [PMID: 5865019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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545
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