1
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Gopalsamy A, Aulabaugh AE, Barakat A, Beaumont KC, Cabral S, Canterbury DP, Casimiro-Garcia A, Chang JS, Chen MZ, Choi C, Dow RL, Fadeyi OO, Feng X, France SP, Howard RM, Janz JM, Jasti J, Jasuja R, Jones LH, King-Ahmad A, Knee KM, Kohrt JT, Limberakis C, Liras S, Martinez CA, McClure KF, Narayanan A, Narula J, Novak JJ, O'Connell TN, Parikh MD, Piotrowski DW, Plotnikova O, Robinson RP, Sahasrabudhe PV, Sharma R, Thuma BA, Vasa D, Wei L, Wenzel AZ, Withka JM, Xiao J, Yayla HG. PF-07059013: A Noncovalent Modulator of Hemoglobin for Treatment of Sickle Cell Disease. J Med Chem 2020; 64:326-342. [PMID: 33356244 DOI: 10.1021/acs.jmedchem.0c01518] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sickle cell disease (SCD) is a genetic disorder caused by a single point mutation (β6 Glu → Val) on the β-chain of adult hemoglobin (HbA) that results in sickled hemoglobin (HbS). In the deoxygenated state, polymerization of HbS leads to sickling of red blood cells (RBC). Several downstream consequences of polymerization and RBC sickling include vaso-occlusion, hemolytic anemia, and stroke. We report the design of a noncovalent modulator of HbS, clinical candidate PF-07059013 (23). The seminal hit molecule was discovered by virtual screening and confirmed through a series of biochemical and biophysical studies. After a significant optimization effort, we arrived at 23, a compound that specifically binds to Hb with nanomolar affinity and displays strong partitioning into RBCs. In a 2-week multiple dose study using Townes SCD mice, 23 showed a 37.8% (±9.0%) reduction in sickling compared to vehicle treated mice. 23 (PF-07059013) has advanced to phase 1 clinical trials.
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Affiliation(s)
- Ariamala Gopalsamy
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Ann E Aulabaugh
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Amey Barakat
- Rare Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Kevin C Beaumont
- Primary Pharmacology Group, Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Shawn Cabral
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Daniel P Canterbury
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Agustin Casimiro-Garcia
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Jeanne S Chang
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Ming Z Chen
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Chulho Choi
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Robert L Dow
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Olugbeminiyi O Fadeyi
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Xidong Feng
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Scott P France
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Roger M Howard
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Jay M Janz
- Rare Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Jayasankar Jasti
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Reema Jasuja
- Rare Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Lyn H Jones
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Amanda King-Ahmad
- Primary Pharmacology Group, Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Kelly M Knee
- Rare Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Jeffrey T Kohrt
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Chris Limberakis
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Spiros Liras
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Carlos A Martinez
- Medicinal Sciences, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Kim F McClure
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Arjun Narayanan
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Jatin Narula
- Primary Pharmacology Group, Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Jonathan J Novak
- Primary Pharmacology Group, Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Thomas N O'Connell
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Mihir D Parikh
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - David W Piotrowski
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Olga Plotnikova
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Ralph P Robinson
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Parag V Sahasrabudhe
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Raman Sharma
- Primary Pharmacology Group, Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Benjamin A Thuma
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Dipy Vasa
- Drug Product Design, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, United States
| | - Liuqing Wei
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - A Zane Wenzel
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Jane M Withka
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Jun Xiao
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Hatice G Yayla
- Pfizer Medicine Design, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
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Abstract
Human hemoglobin is the textbook example of the stereochemistry of an allosteric protein and of the exquisite control that a protein can exert over ligand binding. However, the fundamental basis by which the protein facilitates the ligand movement remains unknown. In this study, we used cryogenic X-ray crystallography and a high-repetition pulsed laser irradiation technique to elucidate the atomic details of ligand migration processes in hemoglobin after photolysis of the bound CO. Our data clarify the distinct CO migration pathways in the individual subunits of hemoglobin and unravel the functional roles of the internal cavities and neighboring amino acid residues in ligand exit and entry. Our results also demonstrate the high gas permeability and porosity of hemoglobin, facilitating O2 delivery. Hemoglobin is one of the best-characterized proteins with respect to structure and function, but the internal ligand diffusion pathways remain obscure and controversial. Here we captured the CO migration processes in the tense (T), relaxed (R), and second relaxed (R2) quaternary structures of human hemoglobin by crystallography using a high-repetition pulsed laser technique at cryogenic temperatures. We found that in each quaternary structure, the photodissociated CO molecules migrate along distinct pathways in the α and β subunits by hopping between the internal cavities with correlated side chain motions of large nonpolar residues, such as α14Trp(A12), α105Leu(G12), β15Trp(A12), and β71Phe(E15). We also observe electron density evidence for the distal histidine [α58/β63His(E7)] swing-out motion regardless of the quaternary structure, although less evident in α subunits than in β subunits, suggesting that some CO molecules have escaped directly through the E7 gate. Remarkably, in T-state Fe(II)-Ni(II) hybrid hemoglobins in which either the α or β subunits contain Ni(II) heme that cannot bind CO, the photodissociated CO molecules not only dock at the cavities in the original Fe(II) subunit, but also escape from the protein matrix and enter the cavities in the adjacent Ni(II) subunit even at 95 K, demonstrating the high gas permeability and porosity of the hemoglobin molecule. Our results provide a comprehensive picture of ligand movements in hemoglobin and highlight the relevance of cavities, nonpolar residues, and distal histidines in facilitating the ligand migration.
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3
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Shibayama N. Allosteric transitions in hemoglobin revisited. Biochim Biophys Acta Gen Subj 2020; 1864:129335. [DOI: 10.1016/j.bbagen.2019.03.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 03/27/2019] [Accepted: 03/30/2019] [Indexed: 12/19/2022]
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Abstract
The methods of synthesis of biologically active nanostructured systems based on functional and natural polymers are reviewed. The formation of nanosystems in the process of interaction between synthetic water-soluble polyelectrolytes and amphiphilic ionic surfactants is discussed. The influence of structure and stability of these systems on their biological activity is considered. The complexation between DNA and polycations with the formation of compacted DNA molecules, and the transport of resulting complexes into the cells are discussed. The data on nanostructuring of hemoglobin using polyfunctional crosslinkers and the data on the use of the obtained nanoparticles as oxygen-transporting blood substitutes are summarized. Using nanodisperse silver stabilized with poly(vinylpyrrolidone) as an example it was demonstrated, that transferring silver into nanodisperse state results in widening its bioactivity.
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Affiliation(s)
- E. F. Panarin
- Institute of High-Molecular Compounds, Russian Academy of Science, 31 Bol’shoi prosp., 199004 St. Petersburg, Russian Federation
- St. Petersburg State Polytechnic University, 29 ul. Politekhnicheskaya, 195251 St. Petersburg, Russian Federation
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5
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Shibayama N, Ohki M, Tame JRH, Park SY. Direct observation of conformational population shifts in crystalline human hemoglobin. J Biol Chem 2017; 292:18258-18269. [PMID: 28931607 DOI: 10.1074/jbc.m117.781146] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 08/15/2017] [Indexed: 11/06/2022] Open
Abstract
Although X-ray crystallography is the most commonly used technique for studying the molecular structure of proteins, it is not generally able to monitor the dynamic changes or global domain motions that often underlie allostery. These motions often prevent crystal growth or reduce crystal order. We have recently discovered a crystal form of human hemoglobin that contains three protein molecules allowed to express a full range of quaternary structures, whereas maintaining strong X-ray diffraction. Here we use this crystal form to investigate the effects of two allosteric effectors, phosphate and bezafibrate, by tracking the structures and functions of the three hemoglobin molecules following the addition of each effector. The X-ray analysis shows that the addition of either phosphate or bezafibrate not only induces conformational changes in a direction from a relaxed-state to a tense-state, but also within relaxed-state populations. The microspectrophotometric O2 equilibrium measurements on the crystals demonstrate that the binding of each effector energetically stabilizes the lowest affinity conformer more strongly than the intermediate affinity one, thereby reducing the O2 affinity of tense-state populations, and that the addition of bezafibrate causes an ∼5-fold decrease in the O2 affinity of relaxed-state populations. These results show that the allosteric pathway of hemoglobin involves shifts of populations rather than a unidirectional conversion of one quaternary structure to another, and that minor conformers of hemoglobin may have a disproportionate effect on the overall O2 affinity.
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Affiliation(s)
- Naoya Shibayama
- From the Department of Physiology, Division of Biophysics, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 and
| | - Mio Ohki
- the Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama 230-0045, Japan
| | - Jeremy R H Tame
- the Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama 230-0045, Japan
| | - Sam-Yong Park
- the Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama 230-0045, Japan
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6
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Size and Shape Controlled Crystallization of Hemoglobin for Advanced Crystallography. CRYSTALS 2017. [DOI: 10.3390/cryst7090282] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
While high-throughput screening for protein crystallization conditions have rapidly evolved in the last few decades, it is also becoming increasingly necessary for the control of crystal size and shape as increasing diversity of protein crystallographic experiments. For example, X-ray crystallography (XRC) combined with photoexcitation and/or spectrophotometry requires optically thin but well diffracting crystals. By contrast, large-volume crystals are needed for weak signal experiments, such as neutron crystallography (NC) or recently developed X-ray fluorescent holography (XFH). In this article, we present, using hemoglobin as an example protein, some techniques for obtaining the crystals of controlled size, shape, and adequate quality. Furthermore, we describe a few case studies of applications of the optimized hemoglobin crystals for implementing the above mentioned crystallographic experiments, providing some hints and tips for the further progress of advanced protein crystallography.
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7
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Fujiwara S, Chatake T, Matsuo T, Kono F, Tominaga T, Shibata K, Sato-Tomita A, Shibayama N. Ligation-Dependent Picosecond Dynamics in Human Hemoglobin As Revealed by Quasielastic Neutron Scattering. J Phys Chem B 2017; 121:8069-8077. [DOI: 10.1021/acs.jpcb.7b05182] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Satoru Fujiwara
- Quantum
Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, 2-4 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Toshiyuki Chatake
- Research
Reactor Institute, Kyoto University, 2 Asashiro-Nishi, Kumatori, Osaka 590-0494, Japan
| | - Tatsuhito Matsuo
- Quantum
Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, 2-4 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Fumiaki Kono
- Quantum
Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, 2-4 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Taiki Tominaga
- Neutron
Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Kaoru Shibata
- Neutron
Science Section, J-PARC Center, 2-4 Shirakata, Tokai, Ibaraki 319-1195, Japan
| | - Ayana Sato-Tomita
- Division
of Biophysics, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Naoya Shibayama
- Division
of Biophysics, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
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8
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Sato-Tomita A, Shibayama N, Happo N, Kimura K, Okabe T, Matsushita T, Park SY, Sasaki YC, Hayashi K. Development of an X-ray fluorescence holographic measurement system for protein crystals. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:063707. [PMID: 27370459 DOI: 10.1063/1.4953453] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Experimental procedure and setup for obtaining X-ray fluorescence hologram of crystalline metalloprotein samples are described. Human hemoglobin, an α2β2 tetrameric metalloprotein containing the Fe(II) heme active-site in each chain, was chosen for this study because of its wealth of crystallographic data. A cold gas flow system was introduced to reduce X-ray radiation damage of protein crystals that are usually fragile and susceptible to damage. A χ-stage was installed to rotate the sample while avoiding intersection between the X-ray beam and the sample loop or holder, which is needed for supporting fragile protein crystals. Huge hemoglobin crystals (with a maximum size of 8 × 6 × 3 mm(3)) were prepared and used to keep the footprint of the incident X-ray beam smaller than the sample size during the entire course of the measurement with the incident angle of 0°-70°. Under these experimental and data acquisition conditions, we achieved the first observation of the X-ray fluorescence hologram pattern from the protein crystals with minimal radiation damage, opening up a new and potential method for investigating the stereochemistry of the metal active-sites in biomacromolecules.
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Affiliation(s)
- Ayana Sato-Tomita
- Division of Biophysics, Department of Physiology, Jichi Medical University, Yakushiji, Shimotsuke 329-0498, Japan
| | - Naoya Shibayama
- Division of Biophysics, Department of Physiology, Jichi Medical University, Yakushiji, Shimotsuke 329-0498, Japan
| | - Naohisa Happo
- Department of Computer and Network Engineering, Graduate School of Information Sciences, Hiroshima City University, Asa-Minami-Ku, Hiroshima 731-3194, Japan
| | - Koji Kimura
- Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555, Japan
| | - Takahiro Okabe
- Division of Biophysics, Department of Physiology, Jichi Medical University, Yakushiji, Shimotsuke 329-0498, Japan
| | - Tomohiro Matsushita
- Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, Sayo, Hyogo 679-5198, Japan
| | - Sam-Yong Park
- Drug Design Laboratory, Department of Medical Life Science, Yokohama City University, Suehiro, Tsurumi, Yokohama 230-0045, Japan
| | - Yuji C Sasaki
- Department of Advanced Material Science, Graduate School of Frontier Science, The University of Tokyo, Kashiwanoha, Kashiwa 277-8561, Japan
| | - Kouichi Hayashi
- Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555, Japan
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9
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Shibayama N, Sugiyama K, Tame JRH, Park SY. Capturing the Hemoglobin Allosteric Transition in a Single Crystal Form. J Am Chem Soc 2014; 136:5097-105. [DOI: 10.1021/ja500380e] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Naoya Shibayama
- Division
of Biophysics, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Kanako Sugiyama
- Drug
Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama, 230-0045, Japan
| | - Jeremy R. H. Tame
- Drug
Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama, 230-0045, Japan
| | - Sam-Yong Park
- Drug
Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama, 230-0045, Japan
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10
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Kuznetsova NP, Panarin EF, Gudkin LR, Mishaeva RN. Biologically active polymer systems based on hemoglobin. Russ Chem Bull 2013. [DOI: 10.1007/s11172-013-0002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Low-lying electronic states of the ferrous high-spin (S=2) heme in deoxy-Mb and deoxy-Hb studied by highly-sensitive multi-frequency EPR. J Inorg Biochem 2011; 105:1596-602. [DOI: 10.1016/j.jinorgbio.2011.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 09/02/2011] [Accepted: 09/02/2011] [Indexed: 11/20/2022]
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12
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Shibayama N. Symmetry distortion in the human hemoglobin tetramer induced by asymmetric ligation. FEBS Lett 2011; 586:74-8. [DOI: 10.1016/j.febslet.2011.11.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 11/23/2011] [Accepted: 11/23/2011] [Indexed: 10/14/2022]
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13
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Kovalevsky A, Chatake T, Shibayama N, Park SY, Ishikawa T, Mustyakimov M, Fisher SZ, Langan P, Morimoto Y. Protonation states of histidine and other key residues in deoxy normal human adult hemoglobin by neutron protein crystallography. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:1144-52. [PMID: 21041929 PMCID: PMC2967419 DOI: 10.1107/s0907444910025448] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 06/28/2010] [Indexed: 11/10/2022]
Abstract
The protonation states of the histidine residues key to the function of deoxy (T-state) human hemoglobin have been investigated using neutron protein crystallography. These residues can reversibly bind protons, thereby regulating the oxygen affinity of hemoglobin. By examining the OMIT F(o)-F(c) and 2F(o)-F(c) neutron scattering maps, the protonation states of 35 of the 38 His residues were directly determined. The remaining three residues were found to be disordered. Surprisingly, seven pairs of His residues from equivalent α or β chains, αHis20, αHis50, αHis58, αHis89, βHis63, βHis143 and βHis146, have different protonation states. The protonation of distal His residues in the α(1)β(1) heterodimer and the protonation of αHis103 in both subunits demonstrates that these residues may participate in buffering hydrogen ions and may influence the oxygen binding. The observed protonation states of His residues are compared with their ΔpK(a) between the deoxy and oxy states. Examination of inter-subunit interfaces provided evidence for interactions that are essential for the stability of the deoxy tertiary structure.
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Affiliation(s)
- Andrey Kovalevsky
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
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14
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Kovalevsky AY, Chatake T, Shibayama N, Park SY, Ishikawa T, Mustyakimov M, Fisher Z, Langan P, Morimoto Y. Direct determination of protonation states of histidine residues in a 2 A neutron structure of deoxy-human normal adult hemoglobin and implications for the Bohr effect. J Mol Biol 2010; 398:276-91. [PMID: 20230836 DOI: 10.1016/j.jmb.2010.03.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 03/06/2010] [Accepted: 03/09/2010] [Indexed: 11/26/2022]
Abstract
We have investigated the protonation states of histidine residues (potential Bohr groups) in the deoxy form (T state) of human hemoglobin by direct determination of hydrogen (deuterium) positions with the neutron protein crystallography technique. The reversible binding of protons is key to the allosteric regulation of human hemoglobin. The protonation states of 35 of the 38 His residues were directly determined from neutron scattering omit maps, with 3 of the remaining residues being disordered. Protonation states of 5 equivalent His residues--alpha His20, alpha His50, alpha His89, beta His143, and beta His146--differ between the symmetry-related globin subunits. The distal His residues, alpha His58 and beta His63, are protonated in the alpha 1 beta 1 heterodimer and are neutral in alpha 2 beta 2. Buried residue alpha His103 is found to be protonated in both subunits. These distal and buried residues have the potential to act as Bohr groups. The observed protonation states of His residues are compared to changes in their pK(a) values during the transition from the T to the R state and the results provide some new insights into our understanding of the molecular mechanism of the Bohr effect.
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Affiliation(s)
- Andrey Y Kovalevsky
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
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15
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Kovalevsky AY, Chatake T, Shibayama N, Park SY, Ishikawa T, Mustyakimov M, Fisher SZ, Langan P, Morimoto Y. Preliminary time-of-flight neutron diffraction study of human deoxyhemoglobin. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:270-3. [PMID: 18391424 PMCID: PMC2374244 DOI: 10.1107/s1744309108005137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Accepted: 02/22/2008] [Indexed: 11/10/2022]
Abstract
Human hemoglobin (HbA) is an intricate system that has evolved to efficiently transport oxygen molecules (O(2)) from lung to tissue. Its quaternary structure can fluctuate between two conformations, T (tense or deoxy) and R (relaxed or oxy), which have low and high affinity for O(2), respectively. The binding of O(2) to the heme sites of HbA is regulated by protons and by inorganic anions. In order to investigate the role of the protonation states of protein residues in O(2) binding, large crystals of deoxy HbA (approximately 20 mm(3)) were grown in D(2)O under anaerobic conditions for neutron diffraction studies. A time-of-flight neutron data set was collected to 1.8 A resolution on the Protein Crystallography Station (PCS) at the spallation source run by Los Alamos Neutron Science Center (LANSCE). The HbA tetramer (64.6 kDa; 574 residues excluding the four heme groups) occupies the largest asymmetric unit (space group P2(1)) from which a high-resolution neutron data set has been collected to date.
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Affiliation(s)
- A. Y. Kovalevsky
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - T. Chatake
- Kyoto University, Research Reactor Institute, Kumatori, Osaka 590-0494, Japan
| | - N. Shibayama
- Jichi Medical University, Department of Physiology, Shimotsuke, Tochigi 329-0498, Japan
| | - S.-Y. Park
- Yokohama City University, Graduate School of Integrated Science, Tsurumi, Yokohama 230-0045, Japan
| | - T. Ishikawa
- Kyoto University, Research Reactor Institute, Kumatori, Osaka 590-0494, Japan
| | - M. Mustyakimov
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - S. Z. Fisher
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - P. Langan
- Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
- Department of Chemistry, University of Toledo, Toledo, OH 53606, USA
| | - Y. Morimoto
- Kyoto University, Research Reactor Institute, Kumatori, Osaka 590-0494, Japan
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17
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Adachi SI, Park SY, Tame JRH, Shiro Y, Shibayama N. Direct observation of photolysis-induced tertiary structural changes in hemoglobin. Proc Natl Acad Sci U S A 2003; 100:7039-44. [PMID: 12773618 PMCID: PMC165826 DOI: 10.1073/pnas.1230629100] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2003] [Indexed: 11/18/2022] Open
Abstract
Human Hb, an alpha2beta2 tetrameric oxygen transport protein that switches from a T (tense) to an R (relaxed) quaternary structure during oxygenation, has long served as a model for studying protein allostery in general. Time-resolved spectroscopic measurements after photodissociation of CO-liganded Hb have played a central role in exploring both protein dynamical responses and molecular cooperativity, but the direct visualization and the structural consequences of photodeligation have not yet been reported. Here we present an x-ray study of structural changes induced by photodissociation of half-liganded T-state and fully liganded R-state human Hb at cryogenic temperatures (25-35 K). On photodissociation of CO, structural changes involving the heme and the F-helix are more marked in the alpha subunit than in the beta subunit, and more subtle in the R state than in the T state. Photodeligation causes a significant sliding motion of the T-state beta heme. Our results establish that the structural basis of the low affinity of the T state is radically different between the subunits, because of differences in the packing and chemical tension at the hemes.
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Affiliation(s)
- Shin-Ichi Adachi
- RIKEN Harima Institute/SPring-8, 1-1-1 Kouto, Mikazuki, Sayo, Hyogo 679-5148, Japan.
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18
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Yun KM, Morimoto H, Shibayama N. The contribution of the asymmetric alpha 1beta 1 half-oxygenated intermediate to human hemoglobin cooperativity. J Biol Chem 2002; 277:1878-83. [PMID: 11714709 DOI: 10.1074/jbc.m108494200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Considerable controversy remains as to the functional and structural properties of the asymmetric alpha1beta1 half-oxygenated intermediate of human hemoglobin, consisting of a deoxygenated and an oxygenated dimer. A recent dimer-tetramer equilibrium study using [Zn(II)/Fe(II)-O(2)] hybrid hemoglobins, in which Zn-protoporphyrin IX mimics a deoxyheme, showed that the key intermediate, [alpha(Fe-O(2))beta(Fe-O(2))][alpha(Zn)beta(Zn)], exhibited an enhanced tetramer stability relative to the other doubly oxygenated species. This is one of the strongest findings in support of distinctly favorable intra-dimer cooperativity within the tetramer. However, we present here a different conclusion drawn from direct O(2) binding experiments for the same asymmetric hybrid, [alpha(Fe)beta(Fe)][alpha(Zn)beta(Zn)], and those for [alpha(Fe)beta(Zn)](2) and [alpha(Zn)beta(Fe)](2). In this study, the O(2) equilibrium curves for [alpha(Fe)beta(Fe)][alpha(Zn)beta(Zn)] were determined by an O(2)-jump stopped-flow technique to circumvent the problem of dimer rearrangement, and those for [alpha(Fe)beta(Zn)]( 2) and [alpha(Zn)beta(Fe)]( 2) were measured by using an Imai apparatus. It was shown that the first and second O(2) equilibrium constants for [alpha(Fe)beta(Fe)][alpha(Zn)beta(Zn)] are 0.0209 mmHg(-1) and 0.0276 mmHg(-1), respectively, that are almost identical to those for [alpha(Fe)beta(Zn)](2) or [alpha(Zn)beta(Fe)](2). Therefore, we did not observe large difference among the asymmetric and symmetric hybrids. The discrepancy between the present and previous studies is mainly due to previously observed negative cooperativity for [alpha(Fe)beta(Zn)](2) and [alpha(Zn)beta(Fe)](2), which is not the case in our direct O(2) binding study.
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Affiliation(s)
- Kyung-Mook Yun
- Department of Physics, Jichi Medical School, Yakushiji 3311-1, Minamikawachi, Kawachi, Tochigi 329-0498, Japan
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19
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Riess JG. Oxygen carriers ("blood substitutes")--raison d'etre, chemistry, and some physiology. Chem Rev 2001; 101:2797-920. [PMID: 11749396 DOI: 10.1021/cr970143c] [Citation(s) in RCA: 544] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- J G Riess
- MRI Institute, University of California at San Diego, San Diego, CA 92103, USA.
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20
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Shibayama N, Saigo S. Direct observation of two distinct affinity conformations in the T state human deoxyhemoglobin. FEBS Lett 2001; 492:50-3. [PMID: 11248235 DOI: 10.1016/s0014-5793(01)02225-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The main features of cooperative oxygenation of human hemoglobin have been described by assuming the equilibrium between two affinity conformations of the entire molecule, T and R. However, the molecular basis for explaining the wide variation in the O(2) affinities of the deoxy T state has remained obscure. We address this long-standing issue by trapping the conformational states of deoxyhemoglobin molecules within wet porous transparent silicate sol-gels. The equilibrium O(2) binding measurements of the encapsulated deoxyhemoglobin samples showed that deoxyhemoglobin free of anions coexists in two conformations that differ in O(2) affinity by 40 times or more, and addition of inositol hexaphosphate to this anion-free deoxyhemoglobin brings about a very slow redistribution of these affinity conformations. These results are the first, direct demonstration of the existence of equilibrium between two (at least two) functionally distinguishable conformational states in the T state deoxyhemoglobin.
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Affiliation(s)
- N Shibayama
- Department of Physics, Jichi Medical School, Yakushiji 3311-1, Minamikawachi, Kawachi, Tochigi 329-0498, Japan.
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21
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Miyazaki G, Morimoto H, Yun KM, Park SY, Nakagawa A, Minagawa H, Shibayama N. Magnesium(II) and zinc(II)-protoporphyrin IX's stabilize the lowest oxygen affinity state of human hemoglobin even more strongly than deoxyheme. J Mol Biol 1999; 292:1121-36. [PMID: 10512707 DOI: 10.1006/jmbi.1999.3124] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Studies of oxygen equilibrium properties of Mg(II)-Fe(II) and Zn(II)-Fe(II) hybrid hemoglobins (i.e. alpha2(Fe)beta2(M) and alpha2(M)beta2(Fe); M=Mg(II), Zn(II) (neither of these closed-shell metal ions binds oxygen or carbon monoxide)) are reported along with the X-ray crystal structures of alpha2(Fe)beta2(Mg) with and without CO bound. We found that Mg(II)-Fe(II) hybrids resemble Zn(II)-Fe(II) hybrids very closely in oxygen equilibrium properties. The Fe(II)-subunits in these hybrids bind oxygen with very low affinities, and the effect of allosteric effectors, such as proton and/or inositol hexaphosphate, is relatively small. We also found a striking similarity in spectrophotometric properties between Mg(II)-Fe(II) and Zn(II)-Fe(II) hybrids, particularly, the large spectral changes that occur specifically in the metal-containing beta subunits upon the R-T transition of the hybrids. In crystals, both alpha2(Fe)beta2(Mg) and alpha2(Fe-CO)beta2(Mg) adopt the quaternary structure of deoxyhemoglobin. These results, combined with the re-evaluation of the oxygen equilibrium properties of normal hemoglobin, low-affinity mutants, and metal substituted hybrids, point to a general tendency of human hemoglobin that when the association equilibrium constant of hemoglobin for the first binding oxygen molecule (K1) approaches 0.004 mmHg(-1), the cooperativity as well as the effect of allosteric effectors is virtually abolished. This is indicative of the existence of a distinct thermodynamic state which determines the lowest oxygen affinity of human hemoglobin. Moreover, excellent agreement between the reported oxygen affinity of deoxyhemoglobin in crystals and the lowest affinity in solution leads us to propose that the classical T structure of deoxyhemoglobin in the crystals represents the lowest affinity state in solution. We also survey the oxygen equilibrium properties of various metal-substituted hybrid hemoglobins studied over the past 20 years in our laboratory. The bulk of these data are consistent with the Perutz's trigger mechanism, in that the affinity of a metal hybrid is determined by the ionic radius of the metal, and also by the steric effect of the distal ligand, if present. However, there remains a fundamental contradiction among the oxygen equilibrium properties of the beta substituted hybrid hemoglobins.
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Affiliation(s)
- G Miyazaki
- Division of Biophysical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan.
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22
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Kluger R, Lock-O'Brie J, Teytelboym A. Connecting Proteins by Design. Cross-Linked Bis-Hemoglobin. J Am Chem Soc 1999. [DOI: 10.1021/ja9910107] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ronald Kluger
- Contribution from the Lash Miller Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6
| | - Jodi Lock-O'Brie
- Contribution from the Lash Miller Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6
| | - Anna Teytelboym
- Contribution from the Lash Miller Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6
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23
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Nakatsukasa T, Nomura N, Miyazaki G, Imai K, Wada Y, Ishimori K, Morishima I, Morimoto H. The artificial alpha1beta1-contact mutant hemoglobin, Hb Phe-35beta, shows only small functional abnormalities. FEBS Lett 1998; 441:93-6. [PMID: 9877172 DOI: 10.1016/s0014-5793(98)01535-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It was previously reported that Hb Philly with a mutation of Phe for Tyr at 35(C1)beta showed non-cooperative oxygen binding with a very high affinity and instability leading to hemolysis. Further, it lacked the 1H-NMR signal at 13.1 ppm from 2,2-dimethyl-2-silapentane-5-sulfonate in normal hemoglobin (Hb A), so that this signal was assigned to a hydrogen bond formed by Tyr-35(C1)beta. Surprisingly, our artificial mutant hemoglobin with the same mutation as Hb Philly showed slightly lowered oxygen affinity, almost normal cooperativity, the 1H-NMR signal at 13.1 ppm and no sign of instability. Our results indicate that the mutation reported for Hb Philly and the assignment of the 13.1 ppm signal need reexamination.
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Affiliation(s)
- T Nakatsukasa
- Division of Biophysical Engineering, Graduate School of Engineering Science, Osaka University, Japan.
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24
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Bao Y, Williamson G. alpha-Tocopherol enhances the peroxidase activity of hemoglobin on phospholipid hydroperoxide. Redox Rep 1997; 3:325-30. [PMID: 9754332 DOI: 10.1080/13510002.1997.11747130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
We have used direct separation of phospholipid hydroperoxide and phospholipid hydroxide by high performance liquid chromatography to examine the phospholipid hydroperoxide peroxidase activity of hemoglobin (Hb) in the presence of hydrogen donors. Hb exhibits phospholipid hydroperoxide peroxidase activity and rapidly breaks down phospholipid hydroperoxide to thiobarbituric acid-reactive substances. However, in the presence of alpha-tocopherol, some phospholipid hydroperoxide is converted to phospholipid hydroxide, which is more stable than the hydroperoxide and is much less reactive with thiobarbituric acid. Other electron donors such as glutathione and ascorbate are less effective than alpha-tocopherol. Free cysteine also shows some ability to reduce phospholipid hydroperoxides to corresponding hydroxides, but cys-93 beta of Hb did not participate in the reaction, as shown by N-ethylmaleimide modification. Hemin alone catalysed the reaction, in the absence of protein. The results therefore show that Hb catalyses an apparent phospholipid hydroperoxide alpha-tocopherol peroxidase reaction due to bound hemin, and that the reduction depends on the ability of hydrogen donors to react with the intermediate phospholipid alkoxyl radical and does not involve reduction by deprotonated sulfhydryl groups.
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Affiliation(s)
- Y Bao
- Department of Biochemistry, Institute of Food Research, Colney, Norwich, UK
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25
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Bettati S, Mozzarelli A, Rossi GL, Tsuneshige A, Yonetani T, Eaton WA, Henry ER. Oxygen binding by single crystals of hemoglobin: The problem of cooperativity and inequivalence of alpha and beta subunits. Proteins 1996. [DOI: 10.1002/(sici)1097-0134(199608)25:4<425::aid-prot3>3.0.co;2-c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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26
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Unzai S, Hori H, Miyazaki G, Shibayama N, Morimoto H. Oxygen equilibrium properties of chromium (III)-iron (II) hybrid hemoglobins. J Biol Chem 1996; 271:12451-6. [PMID: 8647851 DOI: 10.1074/jbc.271.21.12451] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Cr(III)-Fe(II) hybrid hemoglobins, alpha 2(Cr) beta 2(Fe) and alpha 2(Fe) beta 2(Cr), in which hemes in either the alpha- or beta-subunits were substituted with chromium(III) protoporphyrin IX (Cr(III)(PPIX), were prepared and characterized by oxygen equilibrium measurements. Because Cr(III)PPIX binds neither oxygen molecules nor carbon monoxide, the oxygen equilibrium properties of Fe(II) subunits within these hybrids can be analyzed by a two-step oxygen equilibrium scheme. The oxygen equilibrium constants for both hybrids at the second oxygenation step agree with those for human adult hemoglobin at the last oxygenation step (at pH 6.5-8.4 with an without inositol hexaphosphate at 25 degrees C). The similarity between the effects of the Cr(III)PPIX and each subunits' oxygeme on the oxygen equilibrium properties of the counterpart Fe(II) subunits within hemoglobin indicate the utility of Cr(III)PPIX as a model for a permanently oxygenated heme within the hemoglobin molecule. We found that Cr(III)-Fe(II) hybrid hemoglobins have several advantages over cyanomet valency hybrid hemoglobins, which have been frequently used as a model system for partially oxygenated hemoglobins. In contrast to cyanomet heme, Cr(III)PPIX within hemoglobin is not subject to reduction with dithionite or enzymatic reduction systems. Therefore, we could obtain more accurate and reasonable oxygen equilibrium curves of Cr(III)-Fe(II) hybrids in the presence of an enzymatic reduction system, and we could obtain single crystals of deoxy-alpha 2(Cr) beta 2(Fe) when grown in low salt solution in the presence of polyethylene glycol 1000 and 50 mM dithionite.
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Affiliation(s)
- S Unzai
- Department of Biophysical Engineering, Faculty of Engineering Science, Osaka University, Japan
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27
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Michel B, Igić R, Leray V, Deddish PA, Erdös EG. Removal of Arg141 from the alpha chain of human hemoglobin by carboxypeptidases N and M. Circ Res 1996; 78:635-42. [PMID: 8635221 DOI: 10.1161/01.res.78.4.635] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Both human plasma carboxypeptidase N (CPN) and membrane-bound carboxypeptidase M (CPM) released the C-terminal arginine (alpha-Arg141) of the alpha chain of human adult hemoglobin. An arginase contamination present in the hemoglobin preparation, which converted the released arginine to ornithine, was removed by gel filtration. CPM was about 20 times more efficient than CPN or its active subunit in hydrolyzing oxyhemoglobin and cleaved oxyhemoglobin twice as fast as deoxyhemoglobin. The hydrolysis of the peptide bond of alpha-Arg141 accelerated the dissociation rate of the tetramer deoxy-des-alpha-Arg141 hemoglobin to dimers 2500-fold over that of deoxyhemoglobin, as measured by haptoglobin binding. Moreover, the dissociation of the deoxy-des-alpha-Arg141 hemoglobin tetramer to dimers was not affected by 2,3-diphosphoglyceric acid. Des-alpha-Arg141 hemoglobin had a higher oxygen affinity (P50, 5.51 mm Hg; control, 19.94 mm Hg [P50 is the partial pressure of oxygen that gives 50% of the saturation of hemoglobin]) and a lower apparent cooperativity (Hill coefficient: n, 1.02; control, 2.24) than unhydrolyzed hemoglobin. After hemoglobin was incubated in human plasma, its oxygen-binding parameters, the P50, and the Hill coefficient decreased drastically due to cleavage by CPN. In the perfused rat heart, des-alpha-Arg141 hemoglobin was a more effective coronary vasoconstrictor than hemoglobin, possibly because it dissociated to dimers in the coronary vascular bed. A covalently cross-linked hemoglobin was less active than native hemoglobin. The coronary vasoconstriction was caused by multiple factors, including interference with vasodilation by nitric oxide and eicosanoids. Thus, the hydrolysis of hemoglobin by CPM and CPN demonstrated the contribution of the alpha-Arg141 residue to sustaining the tetrameric structure of hemoglobin and its normal oxygen affinity and vasoactivity.
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Affiliation(s)
- B Michel
- Department of Pharmacology, University of Illinois College of Medicine, Chicago 60612, USA
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28
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Kwiatkowski LD, De Young A, Noble RW. Isolation and stability of partially oxidized intermediates of carp hemoglobin: kinetics of CO binding to the mono- and triferric species. Biochemistry 1994; 33:5884-93. [PMID: 8180217 DOI: 10.1021/bi00185a028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The monoliganded and triliganded forms of the asymmetric valency hybrids of carp hemoglobin were isolated using high-performance liquid chromatography. These partially oxidized hybrids were shown to be sufficiently stable to permit the measurement of the kinetics of CO binding. The effects of protons and inositol hexaphosphate on the rates of these reactions were examined. The kinetics of CO recombination with these partially oxidized derivatives were compared to the kinetics of CO binding to the fully ferrous molecule. To a first approximation, the kinetic behavior of the monoferric derivative was consistent with a small shift in the T<==>R equilibrium in favor of the R state. The presence of three ferric ligands resulted in a still greater shift in the conformational equilibrium in favor of the R state. The kinetic behavior of the triferric molecule was similar, but not identical, to that of a fully ferrous molecule which is triliganded with CO. The properties of both asymmetric valency hybrids were responsive to the nature of the ligand; i.e., the rate of CO binding was increased more by the presence of cyanide on the ferric hemes than by water. Not all of the data could be accommodated within the two-state model. For example, there was evidence of an altered T state in the case of the tricyanomet derivative at low pH in the presence of inositol hexaphosphate.
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Affiliation(s)
- L D Kwiatkowski
- Department of Medicine, State University of New York at Buffalo, Veterans Administration Medical Center 14215
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29
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Vandegriff KD, Le Tellier YC. A comparison of rates of heme exchange: site-specifically cross-linked versus polymerized human hemoglobins. ARTIFICIAL CELLS, BLOOD SUBSTITUTES, AND IMMOBILIZATION BIOTECHNOLOGY 1994; 22:443-55. [PMID: 7994367 DOI: 10.3109/10731199409117873] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The stability of the heme-globin interaction of chemically modified human hemoglobin (Hb) was tested by measuring rates of heme loss from methemoglobin. Heme transfer from methemoglobin to human serum albumin was measured by rapid-scanning spectrophotometry, and the resulting absorption matrices were analyzed by singular value decomposition. Unmodified human HbA0, hemoglobin cross-linked between beta subunits with either 2-nor-2-formylpyridoxal 5'-phosphate or 3,5-(dibromosalicyl)fumarate (DBBF), hemoglobin cross-linked between alpha subunits with DBBF, and pyridoxalated hemoglobin polymerized with either glycolaldehyde or glutaraldehyde were tested. Initial rates were evaluated by fitting the time courses to a biexponential equation using a matrix least squares curve-fitting algorithm. Reaction rates fell into two classes: (1) HbA0 and the site-specifically cross-linked hemoglobins, with biphasic rates of heme loss of 0.02 and 0.004 min-1, and (2) polymerized hemoglobins, with 10-20-fold higher rates at 0.5 and 0.03 min-1. The total fitted amplitudes of the reaction depended upon the specific modification: beta beta-cross-linked Hbs < alpha alpha-cross-linked Hb approximately glycolaldehyde polymerized Hb < glutaraldehyde polymerized Hb < HbA0.
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Affiliation(s)
- K D Vandegriff
- Division of Blood Research, Letterman Army Institute of Research, Presidio of San Francisco, CA 94129-6800
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30
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Walder RY, Andracki ME, Walder JA. Preparation of intramolecularly cross-linked hemoglobins. Methods Enzymol 1994; 231:274-80. [PMID: 8041257 DOI: 10.1016/0076-6879(94)31019-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- R Y Walder
- Department of Biochemistry, University of Iowa, Iowa City 52242
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31
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Affiliation(s)
- S L MacDonald
- National Naval Medical Center, Walter Reed Army Institute of Research, Washington, D.C. 20307
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32
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Affiliation(s)
- V W Macdonald
- National Naval Medical Center, Walter Reed Army Institute of Research, Washington, D.C. 20307
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33
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Shibayama N, Imai K, Morimoto H, Saigo S. Oxygen equilibrium properties of asymmetric nickel(II)-iron(II) hybrid hemoglobin. Biochemistry 1993; 32:8792-8. [PMID: 8364027 DOI: 10.1021/bi00085a009] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Asymmetric Ni(II)-Fe(II) hybrid hemoglobin, XL[alpha(Fe)beta(Fe)][alpha(Ni)beta(Ni)], in which the alpha 1 beta 1 dimer containing ferrous protoporphyrin IX and the complementary alpha 2 beta 2 dimer containing Ni(II) protoporphyrin IX were cross-linked between Lys-82 beta 1 and Lys-82 beta 2 by reaction with bis(3,5-dibromosalicyl) fumarate, was synthesized and characterized. We have previously shown that (i) Ni(II) protoporphyrin IX, which binds neither oxygen nor carbon monoxide, mimics a fixed deoxyheme with respect to its effect on the oxygen equilibrium properties of the counterpart iron subunits in both symmetric Ni(II)-Fe(II) hybrid Hbs [Shibayama, N., Morimoto, H., & Miyazaki, G. (1986) J. Mol. Biol. 192, 323-329] and (ii) the cross-linking used in this study little affects the oxygen equilibrium properties of hemoglobin [Shibayama, N., Imai, K., Hirata, H., Hiraiwa, H., Morimoto, H., & Saigo, S. (1991) Biochemistry 30, 8158-8165]. These remarkable features of our model allowed us to measure the oxygen equilibrium curves for the first two steps of oxygen binding to the alpha 1 beta 1 dimer within the hemoglobin tetramer. At all pH values examined, the affinities of this asymmetric hybrid for the first oxygen molecule are as low as those of native hemoglobin. The hybrid did not show cooperative oxygen binding at pH 6.4, while significant cooperativity was observed with rising pH; i.e., the Hill coefficient was increased from 1.41 to 1.53 upon a pH change from 7.4 to 8.4. The electronic absorption spectrum of Ni(II) protoporphyrin IX in the alpha 2 subunit was changed upon carbon monoxide (or oxygen) binding to the alpha 1 beta 1 dimer.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- N Shibayama
- Department of Physics, Jichi Medical School, Tochigi, Japan
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34
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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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