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Somani YB, Soares RN, Gosalia J, Delgado JM, Flanagan M, Basu S, Kim-Shapiro DB, Murias JM, Proctor DN. A single dose of dietary nitrate supplementation protects against endothelial ischemia-reperfusion injury in early postmenopausal women. Appl Physiol Nutr Metab 2022; 47:749-761. [PMID: 35358395 PMCID: PMC10941101 DOI: 10.1139/apnm-2021-0693] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The onset of menopause and accompanying changes to ovarian hormones often precedes endothelial dysfunction in women. In particular, accelerated impairments in macrovascular and microvascular function coincide with the loss of estrogen, as does impaired endothelial responses to ischemia-reperfusion (IR) injury. In healthy, early postmenopausal women (n = 12; 3.9 ± 1.5 years since menopause) we tested the hypothesis that acute dietary nitrate (NO3-) supplementation would improve endothelial function and attenuate the magnitude of endothelial dysfunction following whole-arm IR in comparison with placebo. In this randomized, double-blind, placebo-controlled, crossover study we tested participants before and after NO3--rich (BRnitrate) and NO3--depleted (BRplacebo) beetroot juice (BR) consumption, as well as following IR injury, and 15 min after IR to assess recovery. Analyses with repeated-measures general linear models revealed a condition × time interaction for brachial artery flow-mediated dilation (FMD; P = 0.04), and no interaction effect was found for the near-infrared spectroscopy-derived reperfusion slope (P = 0.86). Follow-up analysis showed a significant decline in FMD following IR injury with BRplacebo in comparison with all other timepoints (all, P < 0.05), while this decline was not present with BRnitrate (all, P > 0.05). Our findings demonstrate that a single dose of dietary NO3- minimizes IR-induced macrovascular endothelial dysfunction in healthy, early postmenopausal women, but does not improve resting macrovascular and microvascular function. Trial registration number: NCT03644472. Novelty: In healthy, early postmenopausal women, a single dose of NO3--rich BR can protect against IR-induced endothelial dysfunction. This protection may be due to nitric oxide bioactivity during IR rather than improved endothelial function prior to the IR protocol per se.
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Affiliation(s)
- Y B Somani
- Department of Kinesiology, Integrative Vascular Physiology Lab, Penn State University, University Park, PA, USA
| | - R N Soares
- Dalton Cardiovascular Research Center, Department of Medicine, University of Missouri, Columbia, MO, USA
| | - J Gosalia
- Department of Kinesiology, Integrative Vascular Physiology Lab, Penn State University, University Park, PA, USA
| | - J M Delgado
- Department of Kinesiology, Integrative Vascular Physiology Lab, Penn State University, University Park, PA, USA
| | - M Flanagan
- Penn State Hershey Family and Community Medicine, University Park, PA, USA
| | - S Basu
- Translational Science Center and Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - D B Kim-Shapiro
- Translational Science Center and Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - J M Murias
- Department of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - D N Proctor
- Department of Kinesiology, Integrative Vascular Physiology Lab, Penn State University, University Park, PA, USA
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Helms CC, Marvel M, Zhao W, Stahle M, Vest R, Kato GJ, Lee JS, Christ G, Gladwin MT, Hantgan RR, Kim-Shapiro DB. Mechanisms of hemolysis-associated platelet activation. J Thromb Haemost 2013; 11:2148-54. [PMID: 24119131 PMCID: PMC3947421 DOI: 10.1111/jth.12422] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND Intravascular hemolysis occurs after blood transfusion, in hemolytic anemias, and in other conditions, and is associated with hypercoagulable states. Hemolysis has been shown to potently activate platelets in vitro and in vivo, and several mechanisms have been suggested to account for this, including: (i) direct activation by hemoglobin (Hb); (ii) increase in reactive oxygen species (ROS); (iii) scavenging of nitric oxide (NO) by released Hb; and (iv) release of intraerythrocytic ADP. OBJECTIVE To elucidate the mechanism of hemolysis-mediated platelet activation. METHODS We used flow cytometry to detect PAC-1 binding to activated platelets for in vitro experiments, and a Siemens' Advia 120 hematology system to assess platelet aggregation by using platelet counts from in vivo experiments in a rodent model. RESULTS We found that Hb did not directly activate platelets. However, ADP bound to Hb could cause platelet activation. Furthermore, platelet activation caused by shearing of red blood cells (RBCs) was reduced in the presence of apyrase, which metabolizes ADP to AMP. The use of ROS scavengers did not affect platelet activation. We also found that cell-free Hb enhanced platelet activation by abrogating the inhibitory effect of NO on platelet activation. In vivo infusions of ADP and purified (ADP-free) Hb, as well as hemolysate, resulted in platelet aggregation, as shown by decreased platelet counts. CONCLUSION Two primary mechanisms account for RBC hemolysis-associated platelet activation: ADP release, which activates platelets; and cell-free Hb release, which enhances platelet activation by lowering NO bioavailability.
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Affiliation(s)
- C. C. Helms
- University of Richmond, Department of Physics, Richmond, VA
| | - M. Marvel
- Wake Forest University, Department of Physics, Winston-Salem, NC
| | - W. Zhao
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC
| | - M. Stahle
- Wake Forest University School of Medicine, Department of Biochemistry, Winston Salem, NC
| | - R. Vest
- Wake Forest University, Department of Physics, Winston-Salem, NC
| | | | - J. S. Lee
- University of Pittsburgh, Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Pittsburgh, PA
- University of Pittsburgh, Vascular Medicine Institute, Pittsburgh, PA
| | - G. Christ
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC
| | - M. T. Gladwin
- University of Pittsburgh, Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Pittsburgh, PA
- University of Pittsburgh, Vascular Medicine Institute, Pittsburgh, PA
| | - R. R. Hantgan
- Wake Forest University School of Medicine, Department of Biochemistry, Winston Salem, NC
| | - D. B. Kim-Shapiro
- Wake Forest University, Department of Physics, Winston-Salem, NC
- Wake Forest University, Translational Science Center, Winston-Salem, NC
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3
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Huang Z, Louderback JG, Goyal M, Azizi F, King SB, Kim-Shapiro DB. Nitric oxide binding to oxygenated hemoglobin under physiological conditions. Biochim Biophys Acta 2001; 1568:252-60. [PMID: 11786232 DOI: 10.1016/s0304-4165(01)00227-6] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We have added nitric oxide (NO) to hemoglobin in 0.1 M and 0.01 M phosphate buffers as well as to whole blood, all as a function of hemoglobin oxygen saturation. We found that in all these conditions, the amount of nitrosyl hemoglobin (HbNO) formed follows a model where the rates of HbNO formation and methemoglobin (metHb) formation (via hemoglobin oxidation) are independent of oxygen saturation. These results contradict those of an earlier report where, at least in 0.01 M phosphate, an elevated amount of HbNO was formed at high oxygen saturations. A radical rethink of the reaction of oxyhemoglobin with NO under physiological conditions was called for based on this previous proposition that the primary product is HbNO rather than metHb and nitrate. Our results indicate that no such radical rethink is called for.
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Affiliation(s)
- Z Huang
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109-7507, USA
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4
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Abstract
The melting of sickle cell hemoglobin (HbS) polymers was induced by rapid dilution using a stopped-flow apparatus. The kinetics of polymer melting were monitored using light scattering. Polymer melting in the absence of any hemoglobin ligand was compared to melting when the diluting buffer was saturated with carbon monoxide (CO). In this way the role of CO in polymer melting could be assessed. The data were analyzed using models that assumed that melting occurs only at the ends of polymers. It was further assumed that CO could only bind to HbS in the solution phase. However, our data could not be fitted to this model, where CO cannot bind directly to the polymer. Thus, CO probably binds directly to the polymers during our melting experiments. This result is discussed in terms of oxygen induced polymer melting and polymerization processes in sickle cell disease
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Affiliation(s)
- S K Aroutiounian
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109-7507, USA
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5
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Abstract
Hydroxyurea is a drug that is used to treat some patients with sickle cell disease. We have measured the deformability of sickle erythrocytes incubated in hydroxyurea in vitro and found that hydroxyurea acts to decrease the deformability of these cells. The deformability of normal erythrocytes was not significantly affected by hydroxyurea except at very high concentrations. Hydroxyurea also did not consistently reduce the deformability of sickle erythrocyte ghosts. We propose that the decreased deformability, observed in vitro, is due to the formation of methemoglobin and other oxidative processes resulting from the reaction of hydroxyurea and oxyhemoglobin. Although the reaction with normal hemoglobin is similar to that of sickle hemoglobin, the sickle erythrocytes are affected more. We propose that the sickle erythrocyte membrane is more susceptible to the reaction products of the reaction of hemoglobin and hydroxyurea. An earlier report has shown that hydroxyurea increases the deformability of erythrocytes in patients on hydroxyurea. Taken together, these data suggest that the improved rheological properties of sickle erythrocytes in vivo are due to the elevated numbers of F cells [cells with fetal hemoglobin]. The presence of the nitrosyl hemoglobin or methemoglobin from the reaction with hydroxyurea may also benefit patients in vivo by reducing sickling.
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Affiliation(s)
- Z Huang
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109-7507, USA
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6
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Vitale DJ, Goldbeck RA, Kim-Shapiro DB, Esquerra RM, Parkhurst LJ, Kliger DS. Near-ultraviolet magnetic circular dichroism spectroscopy of protein conformational states: correlation of tryptophan band position and intensity with hemoglobin allostery. Biochemistry 2000; 39:7145-52. [PMID: 10852712 DOI: 10.1021/bi992823a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The near-UV magnetic circular dichroism spectroscopy of the aromatic amino acid bands of hemoglobin was investigated as a potential probe of structural changes at the alpha(1)beta(2) interface during the allosteric transition. Allosteric effectors were used to direct carp and chemically modified human hemoglobins into the R (relaxed) or T (tense) state in order to determine the heme-ligation-independent spectral characteristics of the quaternary states. The tryptophan magnetic circular dichroism (MCD) peak observed at 293 nm in the R state of N-ethylsuccinimide- (NES-) des-Arg-modified human hemoglobin (Hb) was shifted to a slightly longer wavelength in the T state, consistent with the shift expected for tryptophan acting as a proton donor in a T-state hydrogen bond. Moreover, the increase observed in the T-state MCD intensity of this band relative to the R-state intensity was consistent with the effect expected for proton donation by tryptophan on the basis of the Michl perimeter model of aromatic MCD. The peak-to-trough magnitude of the R - T MCD difference spectrum is equal to 30% of the total R-state peak intensity contributed by all six tryptophans present in the human tetramer; the relative magnitude specific to the two beta37 tryptophans undergoing conformational change is estimated accordingly to be 3 times larger. The Trp-beta37 spectral shift, about 200 cm(-)(1), is in good agreement with the shifts observed in other H-bonded proton donors and provides corroborating spectral evidence for the formation in solution of a T-state Trp beta37-Asp alpha94 hydrogen bond observed in X-ray diffraction studies of deoxyHb crystals.
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Affiliation(s)
- D J Vitale
- Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064, USA
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7
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Rupon JW, Domingo SR, Smith SV, Gummadi BK, Shields H, Ballas SK, King SB, Kim-Shapiro DB. The reactions of myoglobin, normal adult hemoglobin, sickle cell hemoglobin and hemin with hydroxyurea. Biophys Chem 2000; 84:1-11. [PMID: 10723540 DOI: 10.1016/s0301-4622(99)00132-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The kinetics of the reaction of hydroxyurea (HU) with myoglobin (Mb), hemin, sickle cell hemoglobin (HbS), and normal adult hemoglobin (HbA) were determined using optical absorption spectroscopy as a function of time, wavelength, and temperature. Each reaction appeared to follow pseudo-first order kinetics. Electron paramagnetic resonance spectroscopy (EPR) experiments indicated that each reaction produced an FeNO product. Reactions of hemin and the ferric forms of HbA, HbS, and myoglobin with HU also formed the NO adduct. The formation of methemoglobin and nitric oxide-hemoglobin from these reactions may provide further insight into the mechanism of how HU benefits sickle cell patients.
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Affiliation(s)
- J W Rupon
- Department of Chemistry, Wake Forest University, Winston-Salem, NC 27103, USA
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8
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Kim-Shapiro DB, King SB, Shields H, Kolibash CP, Gravatt WL, Ballas SK. The reaction of deoxy-sickle cell hemoglobin with hydroxyurea. Biochim Biophys Acta 1999; 1428:381-7. [PMID: 10434057 DOI: 10.1016/s0304-4165(99)00071-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
In addition to its capacity to increase fetal hemoglobin levels, other mechanisms are implicated in hydroxyurea's ability to provide beneficial effects to patients with sickle cell disease. We hypothesize that the reaction of hemoglobin with hydroxyurea may play a role. It is shown that hydroxyurea reacts with deoxy-sickle cell hemoglobin (Hb) to form methemoglobin (metHb) and nitrosyl hemoglobin (HbNO). The products of the reaction as well as the kinetics are followed by absorption spectroscopy and electron paramagnetic resonance (EPR) spectroscopy. Analysis of the kinetics shows that the reaction can be approximated by a pseudo-first order rate constant of 3.7x10(-4) (1/(s.M)) for the disappearance of deoxy-sickle cell hemoglobin. Further analysis shows that HbNO is formed at an observed average rate of 5.25x10(-5) (1/s), three to four times slower than the rate of formation of metHb. EPR spectroscopy is used to show that the formation of HbNO involves the specific transfer of NO from the NHOH group of hydroxyurea. The potential importance of this reaction is discussed in the context of metHb and HbNO being able to increase the delay time for sickle cell hemoglobin polymerization and HbNO's vasodilating capabilities through conversion to S-nitrosohemoglobin.
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Affiliation(s)
- D B Kim-Shapiro
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA.
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9
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Louderback JG, Aroutiounian SK, Kerr WC, Ballas SK, Kim-Shapiro DB. Temperature and domain size dependence of sickle cell hemoglobin polymer melting in high concentration phosphate buffer. Biophys Chem 1999; 80:21-30. [PMID: 10457594 DOI: 10.1016/s0301-4622(99)00056-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Deoxygenated sickle cell hemoglobin (Hb S) in 1.8 M phosphate buffer, and carbon monoxide (CO) saturated buffer were rapidly mixed using a stopped-flow apparatus. The binding of the CO to the Hb S polymers and the polymer melting was measured by time resolved optical spectroscopy. Polymer melting was associated with decreased turbidity, and CO binding to deoxy-Hb S was monitored by observation of changes in the absorption profile. The reaction temperature was varied from 20 degrees C to 35 degrees C. Polymer domain size at 20 degrees C was also varied. The data for mixtures involving normal adult hemoglobin (Hb A) fit well to a single exponential process whereas it was necessary to include a second process when fitting data involving Hb S. The overall Hb S-CO reaction rate decreased with increasing temperature from 20 degrees C to 35 degrees C, and increased with decreasing domain size. In comparison, Hb A-CO reaction rates increased uniformly with increasing temperature. Two competing reaction channels in the Hb S-CO reaction are proposed, one involving CO binding directly to the polymer and the other involving CO only binding to Hb molecules in the solution phase. The temperature dependence of the contribution of each pathway is discussed.
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Affiliation(s)
- J G Louderback
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109-7507, USA
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10
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Abstract
Sickle cell hemoglobin (HbS) prepared in argon-saturated 1.8 M phosphate buffer was rapidly mixed with carbon monoxide (CO)-saturated buffer. The binding of CO to the sickle hemoglobin and the simultaneous melting of the hemoglobin polymers were monitored by transmission spectroscopy (optical absorption and turbidity). Changes in the absorption profile were interpreted as resulting from CO binding to deoxy-HbS while reduced scattering (turbidity) was attributed to melting (depolymerization) of the HbS polymer phase. Analysis of the data provides insight into the mechanism and kinetics of sickle hemoglobin polymer melting. Conversion of normal deoxygenated, adult hemoglobin (HbA) in high concentration phosphate buffer to the HbA-CO adduct was characterized by an average rate of 83 s-1. Under the same conditions, conversion of deoxy-HbS in the polymer phase to the HbS-CO adduct in the solution phase is characterized by an average rate of 5.8 s-1 via an intermediate species that grows in with a 36 s-1 rate. Spectral analysis of the intermediate species suggests that a significant amount of CO may bind to the polymer phase before the polymer melts.
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Affiliation(s)
- J G Louderback
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109-7507, USA
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11
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Esquerra RM, Goldbeck RA, Kim-Shapiro DB, Kliger DS. Spectroscopic evidence for nanosecond protein relaxation after photodissociation of myoglobin-CO. Biochemistry 1998; 37:17527-36. [PMID: 9860868 DOI: 10.1021/bi9814437] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nanosecond time-resolved absorption and magnetic optical rotatory dispersion (MORD) measurements of photolyzed myoglobin-CO visible bands (500-650 nm) are presented. These measurements reveal a 400 ns process, spectrally distinct from ligand recombination, that accounts for 7% of the observed spectral evolution in the visible absorption bands and 4% in the MORD. The time-resolved MORD, more sensitive to heme coordination geometry than absorption, suggests that this process is most likely associated with protein relaxation on the distal side of the heme pocket, perhaps accompanying rehydration of the deoxymyoglobin photoproduct or accommodation of protein side chains to ligand escape.
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Affiliation(s)
- R M Esquerra
- Department of Chemistry and Biochemistry, University of California at Santa Cruz 95064, USA
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12
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Kim-Shapiro DB, King SB, Bonifant CL, Kolibash CP, Ballas SK. Time resolved absorption study of the reaction of hydroxyurea with sickle cell hemoglobin. Biochim Biophys Acta 1998; 1380:64-74. [PMID: 9545536 DOI: 10.1016/s0304-4165(97)00132-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hydroxyurea has been mixed with hemoglobin S and the reaction was studied using electronic absorption spectroscopy as a function of time and wavelength. The rate of conversion of oxyhemoglobin S to other species was determined and the nature of the reaction products was studied. We also report the formation of methemoglobin (and other reaction products) when deoxyhemoglobin S is combined with hydroxyurea. The probable increase in the formation of methemoglobin, and other potential reaction products such as nitric oxide-hemoglobin, in patients with sickle cell anemia who are taking hydroxyurea as a therapeutic drug is discussed in terms of the pathophysiology of the disease. It is proposed that methemoglobin and possibly nitric oxide-hemoglobin formation may partially explain beneficial effects observed in these patients before their levels of fetal hemoglobin have increased.
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Affiliation(s)
- D B Kim-Shapiro
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109-7507, USA.
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13
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Abstract
The addition of circular or, more generally, elliptical polarization state detection to fast optical absorption spectroscopy can increase the amount of electronic and nuclear conformational information obtained about transient molecular species. To accomplish this, fast circular dichroism methods have emerged over the past decade that overcome the millisecond limit on time resolution associated with conventional modulation techniques and enable structural studies of excited states and kinetic intermediates. This article reviews techniques for time-resolved natural and magnetic circular dichroism spectroscopy covering the picosecond to millisecond time regimes and their applications, with particular emphasis on quasi-null ellipsometric techniques for nanosecond multichannel measurements of circular dichroism. Closely related quasi-null polarimetric techniques for nanosecond optical rotatory dispersion and linear dichroism measurements are also discussed.
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Affiliation(s)
- R A Goldbeck
- Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064-1077, USA.
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14
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Goldbeck RA, Sagle L, Kim-Shapiro DB, Flores V, Kliger DS. Evidence for heme-heme excitonic coupling in the Soret circular dichroism of hemoglobin. Biochem Biophys Res Commun 1997; 235:610-4. [PMID: 9207206 DOI: 10.1006/bbrc.1997.6845] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In order to study interdimer heme-heme electronic interactions in human hemoglobin, the Soret circular dichroism spectrum of the carboxy adduct is measured as a function of protein concentration, the spectrum at the highest concentration representing primarily that of alpha2beta2 tetramers (93%) and the lowest concentration representing primarily alphabeta dimers (68%). The tetramer-dimer difference spectrum, obtained using singular value decomposition and linear least squares fitting from a matrix of CD spectra measured at ten concentrations, is roughly conservative, with a larger negative lobe at shorter wavelengths and a peak-to-trough magnitude that is 18% of the tetramer's maximum Soret CD magnitude. It is tentatively assigned to heme-heme excitonic interactions on the basis of theoretical predictions by R. W. Woody [(1985) in Optical Properties and Structure of Tetrapyrroles (Blauer, G., and Sund, H., Eds.), pp. 239-256, Walter de Gruyter, New York].
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Affiliation(s)
- R A Goldbeck
- Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064, USA.
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