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Nagatomo S, Nagai M, Kitagawa T. Structural origin of cooperativity in human hemoglobin: a view from different roles of α and β subunits in the α2β2 tetramer. Biophys Rev 2022; 14:483-498. [PMID: 35528033 PMCID: PMC9043147 DOI: 10.1007/s12551-022-00945-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/14/2022] [Indexed: 11/26/2022] Open
Abstract
This mini-review, mainly based on our resonance Raman studies on the structural origin of cooperative O2 binding in human adult hemoglobin (HbA), aims to answering why HbA is a tetramer consisting of two α and two β subunits. Here, we focus on the Fe-His bond, the sole coordination bond connecting heme to a globin. The Fe-His stretching frequencies reflect the O2 affinity and also the magnitude of strain imposed through globin by inter-subunit interactions, which is the origin of cooperativity. Cooperativity was first explained by Monod, Wyman, and Changeux, referred to as the MWC theory, but later explained by the two tertiary states (TTS) theory. Here, we related the higher-order structures of globin observed mainly by vibrational spectroscopy to the MWC theory. It became clear from the recent spectroscopic studies, X-ray crystallographic analysis, and mutagenesis experiments that the Fe-His bonds exhibit different roles between the α and β subunits. The absence of the Fe-His bond in the α subunit in some mutant and artificial Hbs inhibits T to R quaternary structural change upon O2 binding. However, its absence from the β subunit in mutant and artificial Hbs simply enhances the O2 affinity of the α subunit. Accordingly, the inter-subunit interactions between α and β subunits are nonsymmetric but substantial for HbA to perform cooperative O2 binding.
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Affiliation(s)
- Shigenori Nagatomo
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 Japan
| | - Masako Nagai
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, 184-0003 Japan
- School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa 920-0942 Japan
| | - Teizo Kitagawa
- Graduate School of Life Science, Picobiology Institute, University of Hyogo, Kouto, Kamigori, Ako-gun Hyogo, 678-1297 Japan
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Chen WR, Yu Y, Zulfajri M, Lin PC, Wang CC. Phthalide Derivatives from Angelica Sinensis Decrease Hemoglobin Oxygen Affinity: A New Allosteric-Modulating Mechanism and Potential Use as 2,3-BPG Functional Substitutes. Sci Rep 2017; 7:5504. [PMID: 28710372 PMCID: PMC5511246 DOI: 10.1038/s41598-017-04554-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/16/2017] [Indexed: 11/09/2022] Open
Abstract
Angelica sinensis (AS), one of the most versatile herbal medicines remains widely used due to its multi-faceted pharmacologic activities. Besides its traditional use as the blood-nourishing tonic, its anti-hypertensive, anti-cardiovascular, neuroprotective and anti-cancer effects have been reported. Albeit the significant therapeutic effects, how AS exerts such diverse efficacies from the molecular level remains elusive. Here we investigate the influences of AS and four representative phthalide derivatives from AS on the structure and function of hemoglobin (Hb). From the spectroscopy and oxygen equilibrium experiments, we show that AS and the chosen phthalides inhibited the oxygenated Hb from transforming into the high-affinity “relaxed” (R) state, decreasing Hb’s oxygen affinity. It reveals that phthalides cooperate with the endogenous Hb modulator, 2,3-bisphosphoglycerate (2,3-BPG) to synergetically regulate Hb allostery. From the docking modeling, phthalides appear to interact with Hb mainly through its α1/α2 interface, likely strengthening four (out of six) Hb “tense” (T) state stabilizing salt-bridges. A new allosteric-modulating mechanism is proposed to rationalize the capacity of phthalides to facilitate Hb oxygen transport, which may be inherently correlated with the therapeutic activities of AS. The potential of phthalides to serve as 2,3-BPG substitutes/supplements and their implications in the systemic biology and preventive medicine are discussed.
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Affiliation(s)
- Wei-Ren Chen
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424, Republic of China
| | - Youqing Yu
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424, Republic of China
| | - Muhammad Zulfajri
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424, Republic of China
| | - Ping-Cheng Lin
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424, Republic of China
| | - Chia C Wang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424, Republic of China. .,Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424, Republic of China.
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Nagatomo S, Nagai Y, Aki Y, Sakurai H, Imai K, Mizusawa N, Ogura T, Kitagawa T, Nagai M. An Origin of Cooperative Oxygen Binding of Human Adult Hemoglobin: Different Roles of the α and β Subunits in the α2β2 Tetramer. PLoS One 2015; 10:e0135080. [PMID: 26244770 PMCID: PMC4526547 DOI: 10.1371/journal.pone.0135080] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 07/17/2015] [Indexed: 02/02/2023] Open
Abstract
Human hemoglobin (Hb), which is an α2β2 tetramer and binds four O2 molecules, changes its O2-affinity from low to high as an increase of bound O2, that is characterized by 'cooperativity'. This property is indispensable for its function of O2 transfer from a lung to tissues and is accounted for in terms of T/R quaternary structure change, assuming the presence of a strain on the Fe-histidine (His) bond in the T state caused by the formation of hydrogen bonds at the subunit interfaces. However, the difference between the α and β subunits has been neglected. To investigate the different roles of the Fe-His(F8) bonds in the α and β subunits, we investigated cavity mutant Hbs in which the Fe-His(F8) in either α or β subunits was replaced by Fe-imidazole and F8-glycine. Thus, in cavity mutant Hbs, the movement of Fe upon O2-binding is detached from the movement of the F-helix, which is supposed to play a role of communication. Recombinant Hb (rHb)(αH87G), in which only the Fe-His in the α subunits is replaced by Fe-imidazole, showed a biphasic O2-binding with no cooperativity, indicating the coexistence of two independent hemes with different O2-affinities. In contrast, rHb(βH92G), in which only the Fe-His in the β subunits is replaced by Fe-imidazole, gave a simple high-affinity O2-binding curve with no cooperativity. Resonance Raman, 1H NMR, and near-UV circular dichroism measurements revealed that the quaternary structure change did not occur upon O2-binding to rHb(αH87G), but it did partially occur with O2-binding to rHb(βH92G). The quaternary structure of rHb(αH87G) appears to be frozen in T while its tertiary structure is changeable. Thus, the absence of the Fe-His bond in the α subunit inhibits the T to R quaternary structure change upon O2-binding, but its absence in the β subunit simply enhances the O2-affinity of α subunit.
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Affiliation(s)
- Shigenori Nagatomo
- Department of Chemistry, University of Tsukuba, Tsukuba, Ibaraki, Japan
- * E-mail: (SN); (TK); (MN)
| | - Yukifumi Nagai
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan,3 School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan,4 Department of Frontier Biosciences, Hosei University, Koganei, Tokyo, Japan,5 Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, Sayo, Sayo-gun, Hyogo, Japan
| | - Yayoi Aki
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan,3 School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan,4 Department of Frontier Biosciences, Hosei University, Koganei, Tokyo, Japan,5 Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, Sayo, Sayo-gun, Hyogo, Japan
| | - Hiroshi Sakurai
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan,3 School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan,4 Department of Frontier Biosciences, Hosei University, Koganei, Tokyo, Japan,5 Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, Sayo, Sayo-gun, Hyogo, Japan
| | - Kiyohiro Imai
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan,3 School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan,4 Department of Frontier Biosciences, Hosei University, Koganei, Tokyo, Japan,5 Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, Sayo, Sayo-gun, Hyogo, Japan
| | - Naoki Mizusawa
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan,3 School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan,4 Department of Frontier Biosciences, Hosei University, Koganei, Tokyo, Japan,5 Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, Sayo, Sayo-gun, Hyogo, Japan
| | - Takashi Ogura
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan,3 School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan,4 Department of Frontier Biosciences, Hosei University, Koganei, Tokyo, Japan,5 Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, Sayo, Sayo-gun, Hyogo, Japan
| | - Teizo Kitagawa
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan,3 School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan,4 Department of Frontier Biosciences, Hosei University, Koganei, Tokyo, Japan,5 Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, Sayo, Sayo-gun, Hyogo, Japan
- * E-mail: (SN); (TK); (MN)
| | - Masako Nagai
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan,3 School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan,4 Department of Frontier Biosciences, Hosei University, Koganei, Tokyo, Japan,5 Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, Sayo, Sayo-gun, Hyogo, Japan
- * E-mail: (SN); (TK); (MN)
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Sato A, Tai H, Nagatomo S, Imai K, Yamamoto Y. Determination of Oxygen Binding Properties of the Individual Subunits of Intact Human Adult Hemoglobin. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2011. [DOI: 10.1246/bcsj.20110104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Ceccarelli M, Ruggerone P, Anedda R, Fais A, Era B, Sollaino MC, Corda M, Casu M. Structure-function relationship in a variant hemoglobin: a combined computational-experimental approach. Biophys J 2006; 91:3529-41. [PMID: 16844744 PMCID: PMC1614504 DOI: 10.1529/biophysj.106.083170] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2006] [Accepted: 05/19/2006] [Indexed: 11/18/2022] Open
Abstract
Our study examines the functional and structural effects of amino acid substitution in the distal side of beta-chains of human Hb Duarte (alpha(2)beta(2)(62Ala-->Pro)). We have compared the functional properties of the purified Hb Duarte with those of HbA, and through proton NMR and molecular dynamics simulations we have investigated their tertiary and quaternary structures. The variant exhibits an increased oxygen affinity with a normal Hill coefficient and Bohr effect. The abnormal function of Hb Duarte is attributed to the presence of a proline residue at the beta62 position, since the functional properties of another Hb variant in the same position, Hb J-Europa (beta(62Ala-->Asp)), have been described as normal. Thereafter (1)H-NMR studies have shown that the beta62 Ala-->Pro substitution causes structural modifications of the tertiary structure of the beta globins, leaving the quaternary structure unaltered. These results have been confirmed by extensive all-atom molecular dynamics simulations. All these findings lead to the conclusion that the beta62 Ala-->Pro substitution produces a destabilization of the E-helix extending downward to the CD corner. Particularly, a cavity near the distal histidine of the beta-chains, connecting the heme pocket to the solvent, is affected, altering the functional properties of the protein molecule.
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Affiliation(s)
- Matteo Ceccarelli
- CNR-INFM SLACS, Dipartimento di Fisica, Università di Cagliari, I-09042 Monserrato, Italy
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Lukin JA, Simplaceanu V, Zou M, Ho NT, Ho C. NMR reveals hydrogen bonds between oxygen and distal histidines in oxyhemoglobin. Proc Natl Acad Sci U S A 2000; 97:10354-8. [PMID: 10962034 PMCID: PMC27028 DOI: 10.1073/pnas.190254697] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Compared with free heme, the proteins hemoglobin (Hb) and myoglobin (Mb) exhibit greatly enhanced affinity for oxygen relative to carbon monoxide. This physiologically vital property has been attributed to either steric hindrance of CO or stabilization of O(2) binding by a hydrogen bond with the distal histidine. We report here the first direct evidence of such a hydrogen bond in both alpha- and beta-chains of oxyhemoglobin, as revealed by heteronuclear NMR spectra of chain-selectively labeled samples. Using these spectra, we have assigned the imidazole ring (1)H and (15)N chemical shifts of the proximal and distal histidines in both carbonmonoxy- and oxy-Hb. Because of their proximity to the heme, these chemical shifts are extremely sensitive to the heme pocket conformation. Comparison of the measured chemical shifts with values predicted from x-ray structures suggests differences between the solution and crystal structures of oxy-Hb. The chemical shift discrepancies could be accounted for by very small displacements of the proximal and distal histidines. This suggests that NMR could be used to obtain very high-resolution heme pocket structures of Hb, Mb, and other heme proteins.
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Affiliation(s)
- J A Lukin
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213-2683, USA
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8
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Perrella M. Understanding mechanisms in a cooperative protein: the CO ligation intermediates of hemoglobin. Biophys Chem 1999; 81:157-78. [PMID: 10535099 DOI: 10.1016/s0301-4622(99)00093-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Hemoglobin is a regulatory component of the oxygen transport to the tissues, and for decades has been a prototype to develop new strategies for the study of the structure/function relationships in proteins. One of the most difficult, and so far, unattained objectives of hemoglobin research has been the study of the hemoglobin molecules in a state of partial ligation with oxygen, or intermediates, as a means of testing theories of cooperativity. A cryogenic technique has been developed for the isolation, identification and quantification of the reaction intermediates of hemoglobin and CO, which in many aspects is a close approximation to the physiological ligand. The technical features that are crucial for the evaluation of the significance of the experimental data obtained using this technique and various approaches to the analysis of the data are reported. The discussion points out the importance of accessing direct information on the nature and concentrations of the intermediates in solution to clarify mechanisms of cooperativity as opposed to the less informative studies of the bulk properties of the solution.
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Affiliation(s)
- M Perrella
- Dipartimento di Scienze e Tecnologie Biomediche, Università di Milano, Segrate, Italy
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9
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Faulkner KM, Bonaventura C, Crumbliss AL. A spectroelectrochemical method for differentiation of steric and electronic effects in hemoglobins and myoglobins. J Biol Chem 1995; 270:13604-12. [PMID: 7775411 DOI: 10.1074/jbc.270.23.13604] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Spectroelectrochemical techniques are described which enable us to compare anion effects on redox curves of structurally distinct hemoglobins with oxygenation curves obtained under equivalent conditions. Nernst plots for tetrameric vertebrate Hbs show evidence of cooperativity, with the T state conformation more resistant to oxidation than the R state. Anions shift the conformation toward the T state and decrease the ease of oxidation, with variations in anion sensitivity similar to those observed in oxygen equilibria. Oxygen binding, unlike electron exchange, is known to be subject to steric constraints that vary considerably in natural and engineered hemoglobins that have differences in the distal residues of the heme pocket. Since oxidation curves are not subject to steric hindrance, anion-induced differences between the oxidation and oxygenation curves can be indicative of anion-induced alterations in the stereochemistry of the heme pocket that alters the ease of ligand entry or exit. Addition of inositol hexaphosphate to solutions of Hb A in 0.2 M nitrate generates such differences: the ease of electron abstraction from deoxy (T state) Hb A is unaffected, while, as previously reported, the oxygenation of deoxy (T state) Hb A is greatly hindered. The difference between inositol hexaphosphate effects on initial stages of oxidation and oxygenation indicates that the explanation for "multiple T states" in oxygen binding lies in the ability of the polyanion to greatly increase steric hindrance to ligand entry, without appreciable changes in the electronic features of the heme environment.
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Affiliation(s)
- K M Faulkner
- Department of Chemistry, Duke University, Durham, North Carolina 27708-0346, USA
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Fetler BK, Simplaceanu V, Ho C. 1H-NMR investigation of the oxygenation of hemoglobin in intact human red blood cells. Biophys J 1995; 68:681-93. [PMID: 7696519 PMCID: PMC1281732 DOI: 10.1016/s0006-3495(95)80229-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Using improved selective excitation methods for protein nuclear magnetic resonance (NMR), we have conducted measurements of the oxygenation of hemoglobin inside intact human red blood cells. The selective excitation methods use pulse shape-insensitive suppression of the water signal, while producing uniform phase excitation in the region of interest and, thus, are suitable for a wide variety of applications in vivo. We have measured the areas of 1H-NMR resonances of the hyperfine-shifted, exchangeable N delta H protons of the proximal histidine residues of the alpha- and beta-chains in deoxyhemoglobin (63 and 76 ppm downfield from the proton resonance of 2,2-dimethyl-2-silapentane-5-sulfonate (DSS), respectively), which are sensitive to the paramagnetic state of the iron, and for which the alpha- and beta-chain resonances are resolved, and from the ring current-shifted gamma 2-CH3 protons of the distal valine residues in oxyhemoglobin (2.4 ppm upfield from DSS), which are sensitive to the conformation of the heme pocket in the oxy state. We have found that the proximal histidine resonances are directly correlated with the degree of oxygenation of hemoglobin, whereas the distal valine resonances appear to be correlated with the conformation in the heme pocket that occurs after the binding of oxygen, in both the presence and absence of 2,3-diphosphoglycerate. In addition, from the proximal histidine resonances, we have observed a preference for the binding of oxygen to the alpha-chain (up to about 10%) of hemoglobin over the beta-chain in both the presence and absence of 2,3-diphosphoglycerate. These new results obtained in intact erythrocytes are consistent with our previous 1H-NMR studies on purified human normal adult hemoglobin. A unique feature of our 1H-NMR method is the ability to monitor the binding of oxygen specifically to the alpha- and beta-chains of hemoglobin both in solution and in intact red blood cells. This information is essential to our understanding of the molecular basis for the hemoglobin molecule serving as the oxygen carrier in vertebrates.
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Affiliation(s)
- B K Fetler
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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Affiliation(s)
- C Ho
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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12
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Tsuneshige A, Zhou Y, Yonetani T. Oxygen equilibrium studies of cross-linked iron-cobalt hybrid hemoglobins. Models for partially ligated intermediates of cobalt hemoglobin. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)49421-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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13
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Perrella M, Davids N, Rossi-Bernardi L. The association reaction between hemoglobin and carbon monoxide as studied by the isolation of the intermediates. Implications on the mechanism of cooperativity. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50341-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Ho C. Proton nuclear magnetic resonance studies on hemoglobin: cooperative interactions and partially ligated intermediates. ADVANCES IN PROTEIN CHEMISTRY 1992; 43:153-312. [PMID: 1442322 DOI: 10.1016/s0065-3233(08)60555-0] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- C Ho
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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15
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Bonaventura C, Cashon R, Bonaventura J, Perutz M, Fermi G, Shih D. Involvement of the distal histidine in the low affinity exhibited by Hb Chico (Lys beta 66—-Thr) and its isolated beta chains. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54459-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Mathews A, Olson J, Renaud J, Tame J, Nagai K. The assignment of carbon monoxide association rate constants to the alpha and beta subunits in native and mutant human deoxyhemoglobin tetramers. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54684-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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17
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The effects of E7 and E11 mutations on the kinetics of ligand binding to R state human hemoglobin. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)84745-2] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Arata Y, Seno Y, Otsuka J. A study on the quaternary structure change of hemoglobin in the ligation process. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 956:243-55. [PMID: 3167072 DOI: 10.1016/0167-4838(88)90141-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In order to inquire into the molecular mechanism underlying the cooperative ligand binding to hemoglobin (Hb), conformational interaction at the interfaces between subunits are investigated on the basis of the atomic coordinates of human deoxy and human carbonmonoxy Hbs. Hypothetical intermediate structures are used, each of which is obtained from the procedure where one or more subunits in deoxy Hb are replaced by the corresponding CO-liganded subunits in carbonmonoxy Hb using the method of superimposition of two sets of atomic coordinates. When either alpha or beta subunit is substituted with the corresponding subunit in carbonmonoxy Hb, serious steric hindrances are produced between alpha 1FG4(92)Arg and beta 2C3(37)Trp or between alpha 1C6(41)Thr and beta 2FG4(97)His, all of which belong to the allosteric core affected directly by ligand binding. These steric hindrances become more serious when both alpha 1(alpha 2) and beta 2(beta 1) subunits are substituted. Therefore the change in the relative distance between iron atom and porphyrin by ligation results in strain in the C-terminal residues as an effect of the steric hindrance between the FG and C segments. However, no steric hindrance can be seen between subunits when the subunits in carbonmonoxy Hb are substituted with the corresponding subunits in deoxy Hb. The nature of the quaternary structural change from liganded to deoxy Hb seems to be different from that from deoxy to liganded Hb.
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Affiliation(s)
- Y Arata
- Department of Technical Education, Faculty of Education, University of the Ryukyus, Okinawa, Japan
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Yao C, Simplaceanu V, Lin AKL, Ho C. Bloch analysis and solvent suppression by soft pulses. Application to Proton NMR investigations of human hemoglobin in H2O and in intact red blood cells. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0022-2364(86)90102-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Miura S, Ho C. Proton nuclear magnetic resonance investigation of cross-linked asymmetrically modified hemoglobins: influence of the salt bridges on tertiary and quaternary structures of hemoglobin. Biochemistry 1984; 23:2492-9. [PMID: 6477880 DOI: 10.1021/bi00306a027] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Asymmetrically modified hemoglobins, [alpha(des-Arg)beta]A[alpha beta]cXL, [alpha(des-Arg-Tyr)beta]A[alpha beta]cXL, [alpha(des-Arg)beta(NES)]A[alpha beta]cXL, and [alpha(des-Arg)beta]A[alpha beta(NES)]cXL, have been prepared from chemically modified human normal adult hemoglobin (Hb A) and mutant hemoglobin C (beta 6Glu----Lys), where the subscript A or C denotes that the alpha beta dimer is from either Hb A or Hb C, respectively, and XL symbolizes a cross-linked hemoglobin prepared by reaction with a bifunctional cross-linking reagent, bis(3,5-dibromosalicyl) fumarate. It has been shown by X-ray crystallography that this bifunctional reagent cross-links the epsilon-amino group of the lysyl residue at position 82 of the two beta chains [Walder, J. A., Walder, R. Y., & Arnone, A. (1980) J. Mol. Biol. 141, 195]. Proton nuclear magnetic resonance spectra of these asymmetrically modified hemoglobins together with their parent hemoglobins, des-Arg(alpha 141) Hb A, des-Arg(alpha 141)-Tyr(alpha 140) Hb A, NES-Hb A and NES-des-Arg(alpha 141) Hb A, have been obtained over the spectral region 5-10 ppm downfield from H2O for the exchangeable proton resonances and 50-80 ppm downfield from H2O for the hyperfine-shifted proximal histidyl N delta H exchangeable proton resonances. The experimental results indicate that the effects on the hyperfine-shifted proximal histidyl N delta H exchangeable proton resonances at pH 6.0 of removing Arg(alpha 141) or Arg(alpha 141)-Tyr(alpha 140) from one of the two alpha subunits are limited to within the alpha subunit from which the carboxyl-terminal amino acids are specifically removed.(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
It is shown that the mean allosteric free energy G0(34,12) measures cooperative dioxygen binding in tetrameric hemoglobins. For human hemoglobin G0(34,12) is slightly temperature enhanced between 10 and 35 degrees C. This remarkable thermal behaviour depends on the presence in Hb of two functionally non-equivalent chains. It is proposed that this made the existence of alpha 2 beta 2 hemoglobins biologically advantageous.
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Potter WT, Hazzard JH, Kawanishi S, Caughey WS. Direct measurement of carbon monoxide bound to different subunits of hemoglobin A in solution and in red cells by infrared spectroscopy. Biochem Biophys Res Commun 1983; 116:719-25. [PMID: 6651834 DOI: 10.1016/0006-291x(83)90584-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Infrared spectra for carbon monoxide bound to alpha and beta subunits of human hemoglobin A have subunit differences near 1950 cm-1 and indicate that 92% of the alpha subunits exist in one conformer and 5% in a second conformer under conditions where 99% of the beta subunit is in only one conformation. The sum of the separated subunit spectra is equivalent to the alpha 2 beta 2 tetramer spectrum. CO infrared spectra indicate that CO displaces O2 from HbO2 in red cells or in solution preferentially at the beta subunits. The measurement of C-O stretch bands provides a direct method for characterization of ligand binding sites within intact cells.
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25
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Nasuda-Kouyama A, Tachibana H, Wada A. Preference of oxygenation between alpha and beta subunits of haemoglobin. Results of multidimensional spectroscopic observation. J Mol Biol 1983; 164:451-76. [PMID: 6842598 DOI: 10.1016/0022-2836(83)90061-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The distribution of oxygen between the subunits of haemoglobin was studied spectrophotometrically. The difficulty in discriminating the spectral changes upon oxygen binding to the alpha or beta subunit can be surmounted by means of multidimensional spectroscopic observations and a correlation analysis of the data. M-type abnormal haemoglobins are used as a control against normal haemoglobin because only one type of its subunits can bind oxygen. A multidimensional spectroscopic measuring system, which has been developed in our laboratory, makes it possible to carry out simultaneous and continuous acquisition of a set of spectroscopic data at several wavelengths on one sample solution during the course of increasing or decreasing the partial pressure of oxygen. The data-storing function of a magnetic disk memory provides enough precision for a rigorous investigation of the correlation of oxygen equilibrium curves measured at several wavelengths. No chemical modification to enhance the spectral difference between subunits is necessary. In conclusion, by detecting slight differences between the oxygenation-sensitive bands of alpha and beta subunits, the beta subunits are found to have a higher affinity for oxygen than the alpha subunits.
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26
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Peller L. Cooperative deoxygenation of haemoglobin: asymmetry of binding and subunit differences. Nature 1982; 300:661-2. [PMID: 7144918 DOI: 10.1038/300661a0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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27
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Takahashi S, Lin AK, Ho C. A proton nuclear magnetic resonance investigation of proximal histidyl residues in human normal and abnormal hemoglobins. A probe for the heme pocket. Biophys J 1982; 39:33-40. [PMID: 7104448 PMCID: PMC1328907 DOI: 10.1016/s0006-3495(82)84487-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Proton nuclear magnetic resonance spectroscopy at 250 MHz has been used to investigate the conformations of proximal histidyl residues of human normal adult hemoglobin, hemoglobin Kempsey [beta 99(G1) Asp leads to Asn], hemoglobin Osler [beta 145(HC2) Tyr leads to Asp], and hemoglobin McKees Rocks [beta 145(HC2) Tyr leads to Term] around neutral pH in H2O at 27 degrees C, all in the deoxy form. Two resonances that occur between 58 and 76 ppm downfield from the water proton signal have been assigned to the hyperfine shifted proximal histidyl NH-exchangeable protons of the alpha- and beta-chains of deoxyhemoglobin. These two resonances are sensitive to the quaternary state of hemoglobin, amino acid substitutions in the alpha 1 beta 2-subunit interface and in the carboxy-terminal region of the beta-chain, and the addition of organic phosphates. The experimental results show that there are differences in the heme pockets among these four hemoglobins studied. The structural and dynamic information derived from the hyperfine shifted proximal histidyl NH-exchangeable proton resonances complement that obtained from the ferrous hyperfine shifted and exchangeable proton resonances of deoxyhemoglobin over the spectral region from 5 to 20 ppm downfield from H2O. The relationship between these findings and Perutz's stereochemical mechanism for the cooperative oxygenation of hemoglobin is discussed.
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28
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Johnson ML, Ackers GK. Thermodynamic analysis of human hemoglobins in terms of the Perutz mechanism: extensions of the Szabo--Karplus model to include subunit assembly. Biochemistry 1982; 21:201-11. [PMID: 7074009 DOI: 10.1021/bi00531a001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The stereochemical postulates of Perutz for the mechanism of hemoglobin [Perutz, M. F. (1970) Nature (London) 228, 726--739] have been formulated into a statistical thermodynamic model. The model is based on that of Szabo and Karplus [Szabo, A., & Karplus, M. (1972) J. Mol. Biol 72, 163--197] but has been extended to include the properties of dissociated dimers in equilibrium with tetramers. The dissociation eliminates the alpha 1 beta 2 intersubunit contact which is the major site of ligand-linked structure change. The model quantitatively describes the coupling between binding of oxygen and protons in dimers and tetramers, the change in quaternary structure, and the breaking of salt bridges which are assumed to stabilize the deoxy quaternary structure. The extended model has been tested against an extensive series of recent experimental data from our laboratory and elsewhere on the ligand-linked dimer-tetramer assembly in normal human hemoglobin A and in the variant hemoglobin Kansas (beta 102 Asp leads to Asn). Two versions of the model were used which differ in the properties of the dissociated dimers. For both hemoglobins, the models were found capable of simultaneously describing the data on the ligand-linked dimer-tetramer assembly and predicting the tetramer Bohr effect. However, neither model predicted reasonable values for the tetramer Bohr effect without simultaneously predicting unreasonable values for the affinities of individual chains. Both models incorrectly predict preferential binding of oxygen to the alpha or beta chains within the tetramer. These results argue against the Perutz mechanism for the molecular processes of hemoglobin.
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29
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Nieto JL. 1H NMR study of the binding of 2,3-diphosphoglycerate to human oxyhemoglobin A in intact red cells. FEBS Lett 1981; 136:85-8. [PMID: 7319063 DOI: 10.1016/0014-5793(81)81219-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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30
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Ackers GK, Johnson ML. Linked functions in allosteric proteins. Extension of the concerted (MWC) model for ligand-linked subunit assembly and its application to human hemoglobins. J Mol Biol 1981; 147:559-82. [PMID: 7277501 DOI: 10.1016/0022-2836(81)90400-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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31
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32
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Adachi K, Matarasso SL, Asakura T. Nucleation-controlled aggregation of deoxyhemoglobin S. Effect of organic phosphates on the kinetics of aggregation of deoxyhemoglobin S in concentrated phosphate buffer. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 624:372-7. [PMID: 7417483 DOI: 10.1016/0005-2795(80)90078-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The kinetics of the aggregatin of deoxyhemoglobin S in concentrated phosphate buffer were studied turbidimetrically in the presence of organic phosphates. The addition of inositol hexsphosphate shortened the delay time by 35-80%, the range depending on the hemoglobin concentration. The logarithmic plot of delay time versus hemoglobin concentration in 1.85 M potassium phosphate buffer, pH 7.34, showed a linear relationship with a slope (n value) of 2.5 +/- 0.14 in the absence of inositol hexaphosphate, while the slope was decreased to 2.1 in the presence of inositol hexaphosphate. The turbidity (A700) of aggregates per g deoxy Hb S was found to be lower in the presence of inositol hexaphosphate than in the absence of inositol hexaphosphate. The solubility of deoxy Hb S was decreased by inositol hexaphosphate. 2,3-Diphosphoglyceric acid also showed an effect similar to that of inositol hexaphosphate. However, if the pentacyclohexylammonium salt of diphosphoglyceric acid were used, the delay time was increased significantly. The opposite effect of the pentacyclohexylammonium salt of diphosphoglyceric acid on the delay time was found to be attributed to the anti-gelation effect of the pentacyclohexoxylammonium ion. The difference in the effect of inositol hexaphosphate and diphosphoglyceric acid on the delay time appears to be related to their effect on the solubility of deoxy Hb S.
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33
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Ikeda-Saito M, Yonetani T. Studies on cobalt myoglobins and hemoglobins. XI. The interaction of carbon monoxide and oxygen with alpha and beta subunits in iron-cobalt hybrid hemoglobins. J Mol Biol 1980; 138:845-58. [PMID: 7411625 DOI: 10.1016/0022-2836(80)90068-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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34
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Imai K, Ikeda-Saito M, Yamamoto H, Yonetani T. Studies on cobalt myoglobins and hemoglobins X. Determination of microscopic oxygen-equilibrium constants of iron--cobalt hybrid hemoglobins and their parent hemoglobins. J Mol Biol 1980; 138:635-48. [PMID: 7411619 DOI: 10.1016/s0022-2836(80)80021-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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35
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Morishima I, Ogawa S, Yamada H. High-pressure proton nuclear magnetic resonance studies of hemoproteins. Pressure-induced structural change in heme environments of myoglobin, hemoglobin, and horseradish peroxidase. Biochemistry 1980; 19:1569-75. [PMID: 7378366 DOI: 10.1021/bi00549a006] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Hyperfine shifted proton NMR spectra of metmyoglobin, methemoglobin, and their complexes with azide, imidazole, and cyanide as well as the spectrum of native horseradish peroxidase were obtained at high pressures up to 2000 atm with a specially designed high-pressure cell for 220-MHz superconducting NMR spectrometer. For the azide complexes of metmyoglobin, in all of which the iron atoms are in thermal spin equilibrium between high- and low-spin states, the increased pressure shifted their heme methyl proton signals to the upfield side. For the cyanide complexes of metmyoglobin and methemoglobin and for the fluoride complex of metmyoglobin, which are in purely low- and high-spin states, respectively, the spectra were almost insensitive to changes in pressure up to 2000 atm. The heme methyl proton signals of aquometmyoglobin, its formate complex, and horseradish peroxidase showed appreciable upfield shifts upon pressurization. These results were interpreted to indicate that the primary effect of pressure on the hemoprotein structure is to shift the spin equilibrium in favor of the low-spin form. Hemichrome formation of methemoglobin at high pressures was also observed, and the effect of pressure on the heme environmental structure of deoxyhemoglobin and deoxymyoglobin was also discussed.
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36
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Russu IM, Ho NT, Ho C. Role of the beta 146 histidyl residue in the alkaline Bohr effect of hemoglobin. Biochemistry 1980; 19:1043-52. [PMID: 7356961 DOI: 10.1021/bi00546a033] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
High-resolution proton nuclear magnetic resonance spectroscopy has been used to investigate the effects of inorganic anions, such as phosphate or chloride, on the alkaline Bohr effect of normal human adult hemoglobin. By monitoring the chemical shift of the C2 proton of the beta 146 histidyl residue as a function of pH, we have determined its pK values in both ligated and unligated forms. In the presence of 0.1 M Bis-Tris buffer (with chloride ion concentration ranging from 0.005 to 0.06 M) in D2O at 27 degrees C, the pK value of the beta 146 histidine of deoxyhemoglobin is 7.98 +/- 0.03 and that of (carbon monoxy)hemoglobin is 7.85 +/- 0.03. However, in the presence of 0.2 M phosphate and 0.2 M NaCl in D2O at 27 degrees C, the corresponding pK values are 8.08 and 7.14, as previously reported by this laboratory [Kilmartin, J. V., Breen, J. J., Roberts, G. C. K., & Ho, C. (1973) Proc. Natl. Acad. Sci. U.S.A. 70, 1246-1249]. This large difference in the pK value between the deoxy and carbon monoxy forms in the presence of 0.2 M phosphate and 0.2 M NaCl was interpreted as direct support for (1) the breaking of an intrasubunit salt bridge between beta 146 histidine and beta 94 aspartate when the hemoglobin molecule undergoes the quaternary structural transition as proposed by Perutz [Perutz, M. F. (1970) Nature (London) 228, 726-739] and (2) Perutz's suggestion that the beta 146 histidine is one of the amino acid residues responsible for the alkaline Bohr effect. The absence of a large change in the pK value of the beta 146 histidine in the presence of 0.1 M Bis-Tris buffer implies that (1) the above-mentioned intrasubunit salt bridge is not broken in going from the deoxy to the carbon monoxy form and (2) the beta 146 histidyl residue does not contribute significantly to the alkaline Bohr effect under these conditions. We have also found that in measuring the oxygen affinity of hemoglobin as a function of pH in the presence of 0.1 M Bis-Tris or 0.2 M phosphate plus 0.2 M NaCl (both in D2O), there is no significant difference in the alkaline Bohr effect in these two media. Hence, our results suggest that the detailed molecular mechanism for the Bohr effect depends on the experimental conditions.
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37
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38
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The linkage between oxygenation and subunit association in human hemoglobin Kansas. Concentration dependence of the oxygen binding equilibria. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(19)86327-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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39
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Abstract
The tertiary structures of all liganded hemoglobins in the R state differ in detail. Steric hindrance arising from nonbonded ligand-globin interactions affects the binding of ligands such as CO and cyanide which preferentially form linear axial complexes to heme; these ligands bind in a strained off-axis configuration. Ligands such as O2 and NO, which preferentially form bent complexes, encounter less steric hindrance and can bind in their (preferred) unstrained configuration. Linear complexes distort the ligand pockets in the R state (and by inference, in the T state) more than bent complexes. These structural differences between linear and bent complexes are reflected in the kinetic behavior of hemoglobin. Structural interpretation of this kinetic behavior indicates that the relative contributions of nonbonded ligand-globin interactions and nonbonded heme interactions to transition state free energies differ for linear and bent ligands. The relative contributions of these interactions to the free energy of cooperativity may also differ for linear and bent ligands. Thus the detailed molecular mechanism by which the affinity of heme is regulated differs for different ligands.
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40
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Viggiano G, Ho NT, Ho C. Proton nuclear magnetic resonance and biochemical studies of oxygenation of human adult hemoglobin in deuterium oxide. Biochemistry 1979; 18:5238-47. [PMID: 497180 DOI: 10.1021/bi00590a031] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The proton nuclear magnetic resonance spectrum of human adult deoxyhemoglobin in D2O in the region from 6 to 20 ppm downfield from the proton resonance of residual water shows a number of hyperfine shifted proton resonances that are due to groups on or near the alpha and beta hemes. The sensitivity of these resonances to the ligation of the heme groups and the assignment of these resonances to the alpha and beta chains provide an opportunity to investigate the cooperative oxygenation of an intact hemoglobin molecule in solution. By use of the nuclear magnetic resonance correlation spectroscopy technique, at least two resonances, one at approximately 18 ppm downfield from HDO due to the beta chain and the other at approximately 12 ppm due to the alpha chain, can be used to study the binding of oxygen to the alpha and beta chains of hemoglobin. The present results using approximately 12% hemoglobin concentration in 0.1 M Bistris buffer at pD 7 and 27 degrees C with and without organic phosphate show that there is no significant line broadening on oxygenation (from 0 to 50% saturation) to affect the determination of the intensities or areas of these resonances. It is found that the ratio of the intensity of the alpha-heme resonance at 12 ppm to that of the beta-heme resonance at 18 ppm is constant on oxygenation in the absence of organic phosphate but decreases in the presence of 2,3-diphosphoglycerate or inositol hexaphosphate, with the effect of the latter being the stronger. On oxygenation, the intensities of the alpha-heme resonance at 12 ppm and of the beta-heme resonance at 18 ppm decreases more than the total number of deoxy chains available as measured by the degree of O2 saturation of hemoglobin. This shows the sensitivity of these resonances to structural changes which are believed to occur in the unligated subunits upon the ligation of their neighbors in an intact tetrameric hemoglobin molecule. A comparison of the nuclear magnetic resonance data with the populations of the partially saturated hemoglobin tetramers (i.e., hemoglobin with one, two, or three oxygen molecules bound) leads to the conclusion that in the presence of organic phosphate the hemoglobin molecule with one oxygen bound maintains the beta-heme resonance at 18 ppm but not the alpha-heme resonance at 12 ppm. These resluts suggest that some cooperativity must exist in the deoxy quaternary structure of the hemoglobin molecule during the oxygenation process. Hence, these results are not consistent with the requirements of two-state concerted models for the oxygenation of hemoglobin. In addition, we have investigated the effect of D2O on the oxygenation of hemoglobin by measuring the oxygen dissociation curves of normal adult hemoglobin as a function of pH in D2O andH2O media. We have found that (1) the pH dependence of the oxygen equilibrium of hemoglobin (the Bohr effect) in higher pH in comparison to that in H2O medium and (2) the Hill coefficients are essentially the same in D2O and H2O media over the pH range from 6.0 to 8.2...
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41
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Neya S, Morishima I. Proton NMR study of methemoglobin and its isolated chains. Effect of the subunit association on the structure of the subunits. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(19)86817-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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43
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Mansouri A. Non-equivalent behavior of alpha and beta subunits in methemoglobin reduction. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 579:191-9. [PMID: 465529 DOI: 10.1016/0005-2795(79)90098-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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44
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Ikeda-Saito M, Inubushi T, McDonald G, Yonetani T. Studies on cobalt myoglobins and hemoglobins. Proton magnetic resonance investigation of the subunit interaction in iron-cobalt hybrid hemoglobins. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34473-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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45
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Johnson ME, Scholler DM, Hoffman BM, Ho C. Tertiary structure variability within the quaternary states of hemoglobin: a spin label study. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 535:193-205. [PMID: 678549 DOI: 10.1016/0005-2795(78)90085-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Using variable temperature techniques, the spin label spectral resolution of hemoglobin labeled at the beta93 cysteines with N-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)iodonacetamide has been greatly enhanced. The effects of different ligands, inositol hexaphosphate, pH and salt concentration upon spin labeled ferrous and ferric hemoglobin indicate that the beta chain tertiary structure exhibits considerable variability within the oxy and deoxy quaternary structures. From these studies ligand and spin state changes both appear to be of significance in producing structural changes; binding of inositol hexaphosphate then produces further structural changes secondary in amplitude.
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46
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Taketa F, Antholine W, Chen J. Chain nonequivalence in binding of nitric oxide to hemoglobin. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)30393-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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47
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Makino N, Sugita Y. Oxygen equilibria of hybrid-heme hemoglobins containing proto- and mesoheme groups. On the nonequivalence of alpha and beta chains. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)38126-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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48
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49
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Fung LW, Minton AP, Lindstrom TR, Pisciotta AV, Ho C. Proton nuclear magnetic resonance studies of hemoglobin M Milwaukee and their implications concerning the mechanism of cooperative oxygenation of hemoglobin. Biochemistry 1977; 16:1452-62. [PMID: 849426 DOI: 10.1021/bi00626a033] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Hemoglobin M Milwaukee (beta67E11 Val leads to Glu) is a naturally occurring valency hybrid containing two permanently oxidized hemes on the beta chains. In this mutant, the two abnormal beta chains cannot combine with ligands whereas the two alpha chains are normal and can combine with oxygen with a Hill coefficient varying from 1.1 to 1.3 [Udem et al. (1970), J Mol. Biol. 48, 489]. High-resolution proton nuclear magnetic resonance spectroscopy at 250 MHz has been used to investigate the exchangeable, ring-current shifted, ferrous and ferric hyperfine shifted resonances of Hb M Milwaukee in the absence and presence of organic phosphates. The alpha-heme environment, as manifested by the ring-current shifted resonances in the liganded form as well as the ferrous hyperfine shifted resonances in unliganded form, and subunit interactions, as manifested by the exchangeable resonances, are similar in Hb M Milwaukee to those in normal adult human hemoglobin. Organic phosphates can partially or completely inhibit the structural transformation which normally accompanies the binding of oxygen or carbon monoxide to Hb M Milwaukee. Upon stepwise addition of oxygen to deoxy Hb M Milwaukee, the hyperfine shifted resonance spectra of ferric beta chains show features which cannot be attributed to either fully deoxy or oxy species. However, the spectra for partially oxygenated Hb M Milwaukee can be described as an appropriately weighted average of the spectra of sero, singly, and doubly oxygenated species. The ferric hyperfine shifted resonance spectrum of the singly oxygenated intermediate has been calculated by a method employing least-squares analysis of the spectra of partially oxygenated Hb M Milwaukee at several values of oxygen saturation. The spectrum of this intermediate exhibits features which cannot be accounted for by a two-structure model. The present results are consistent with a sequential model for the oxygenation of this mutant hemoglobin. In view of the similarities between normal adult hemoglobin and Hb M Milwaukee, it is suggested that a two-state concerted allosteric model does not provide an adequate description of the structure-function relationship in normal adult hemoglobin.
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50
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Matthew JB, Morrow JS, Wittebort RJ, Gurd FR. Quantitative determination of carbamino adducts of alpha and beta chains in human adult hemoglobin in presence and absence of carbon monoxide and 2,3-diphosphoglycerate. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)40546-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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