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1.
J Biol Chem ; 289(32): 22342-57, 2014 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-24939847

RESUMO

A pathogenic V67M mutation occurs at the E11 helical position within the heme pockets of variant human fetal and adult hemoglobins (Hb). Subsequent post-translational modification of Met to Asp was reported in γ subunits of human fetal Hb Toms River (γ67(E11)Val → Met) and ß subunits of adult Hb (HbA) Bristol-Alesha (ß67(E11)Val → Met) that were associated with hemolytic anemia. Using kinetic, proteomic, and crystal structural analysis, we were able to show that the Met → Asp transformation involves heme cycling through its oxoferryl state in the recombinant versions of both proteins. The conversion to Met and Asp enhanced the spontaneous autoxidation of the mutants relative to wild-type HbA and human fetal Hb, and the levels of Asp were elevated with increasing levels of hydrogen peroxide (H2O2). Using H2(18)O2, we verified incorporation of (18)O into the Asp carboxyl side chain confirming the role of H2O2 in the oxidation of the Met side chain. Under similar experimental conditions, there was no conversion to Asp at the αMet(E11) position in the corresponding HbA Evans (α62(E11)Val → Met). The crystal structures of the three recombinant Met(E11) mutants revealed similar thioether side chain orientations. However, as in the solution experiments, autoxidation of the Hb mutant crystals leads to electron density maps indicative of Asp(E11) formation in ß subunits but not in α subunits. This novel post-translational modification highlights the nonequivalence of human Hb α, ß, and γ subunits with respect to redox reactivity and may have direct implications to α/ß hemoglobinopathies and design of oxidatively stable Hb-based oxygen therapeutics.


Assuntos
Heme/metabolismo , Hemoglobinas/química , Hemoglobinas/metabolismo , Ferro/metabolismo , Adulto , Sequência de Aminoácidos , Substituição de Aminoácidos , Ácido Aspártico/química , Cristalografia por Raios X , Hemoglobina Fetal/química , Hemoglobina Fetal/genética , Hemoglobina Fetal/metabolismo , Heme/química , Hemoglobina A/química , Hemoglobina A/genética , Hemoglobina A/metabolismo , Hemoglobinas/genética , Hemoglobinas Anormais/química , Hemoglobinas Anormais/genética , Hemoglobinas Anormais/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Ferro/química , Metionina/química , Modelos Moleculares , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Oxirredução , Processamento de Proteína Pós-Traducional , Subunidades Proteicas , Proteômica , Eletricidade Estática
2.
Res Sq ; 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38766242

RESUMO

Blood storage lesion induces cytosolic and membrane changes driven in part by hemoglobin (Hb) oxidation reactions within red blood cells (RBCs). A novel gel formulation containing the antioxidant curcuminoids in a biocompatible solvent system was used to deliver curcumin into RBCs. Incubation of peroxide treated RBCs stored in PBS with curcumin gel led to a reduction in prooxidant ferrylHb and recovery in ATP. Curcumin treatment prevented band 3 tyrosine (Y359 and Y21) phosphorylation. RBCs stored in AS-3 solutions for 28, 35, 42 and 49 days, following a single-dose of 100µM curcuminoids at each time points, caused reduction in protein carbonylation and considerable recovery in ATP levels. Proteomic analysis revealed minimal changes in the proteomic landscape in 35 days. However, a downregulation in fibrinogen was observed in the treated samples which may reduce RBC aggregation. Additionally, we used a guinea pig model where the circulation of infused aged RBCs can be extended (approximately 10%) when treated with curcumin gel at the start of storage. Our data therefore provide mechanistic insights and supportive animal data into benefits of treating stored RBCs with a novel curcuminoid formulation based on the biopreservation of RBC membrane integrity, redox balance, and increased longevity in circulation.

3.
Front Physiol ; 14: 1278763, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37916221

RESUMO

Red blood cells (RBCs) undergo metabolic, oxidative, and physiological changes during storage, collectively described as the "storage lesion." The impact of storage on oxygen homeostasis, following transfusion, is not fully understood. We show that RBC storage induces changes in oxygen binding that were linked to changes in oxygen sensing (hypoxia-inducible factor, HIF-1α) mechanisms and mitochondrial respiration in human pulmonary arterial endothelial cells (HPAECs). A decrease in oxygen affinity (P50) to approximately 20 from 30 mmHg was seen at the first week but remained unchanged for up to 42 days. This led to the suppression of HIF-1α in the first 3 weeks due to limited oxygen supplies by RBCs. Furthermore, membrane oxidative damage, band 3 alterations, and subsequent microparticle (MP) formation were also noted. Mass spectrometric analysis revealed the upregulation of transitional endoplasmic reticulum ATPase, essential for clearing ROS-damaged membrane proteins and the protein DDI1 homolog, a proteasomal shuttle chaperone. Band 3 complex proteins and superoxide dismutase were among the downregulated proteins. Mitochondrial oxygen consumption rates measured in HPAECs incubated with RBC-derived MPs (14-day and 42-day) showed a rise in maximal respiration. Intervention strategies that target intracellular hemoglobin (Hb)'s redox transitions and membrane changes may lead to the reestablishment of oxygen homeostasis in old RBCs.

4.
Biochemistry ; 50(45): 9752-66, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21977904

RESUMO

We have previously shown that hydrogen peroxide (H(2)O(2)) triggers irreversible oxidation of amino acids exclusive to the ß-chains of purified human hemoglobin (HbAo). However, it is not clear, whether α- or ß-subunit Hb variants exhibit different oxidative resistance to H(2)O(2) when compared to their native HbAo. Hb Providence contains two ß-subunit variants with single amino acid mutations at ßLys82→Asp (ßK82D) and at ßLys82→Asn (ßK82N) positions and binds oxygen at lower affinity than wild type HbA. We have separated Hb Providence into its 3 component fractions, and contrasted oxidative reactions of its ß-mutant fractions with HbAo. Relative to HbAo, both ßK82N and ßK82D fractions showed similar autoxidation kinetics and similar initial oxidation reaction rates with H(2)O(2). However, a more profound pattern of changes was seen in HbAo than in the two Providence fractions. The structural changes in HbAo include a collapse of ß-subunits, and α-α dimer formation in the presence of excess H(2)O(2). Mass spectrometric and amino acid analysis revealed that ßCys93 and ßCys112 were oxidized in the HbAo fraction, consistent with oxidative pathways driven by a ferrylHb and its protein radical. These amino acids were oxidized at a lesser extent in ßK82D fraction. While the 3 isolated components of Hb Providence exhibited similar ligand binding and oxidation reaction kinetics, the variant fractions were more effective in consuming H(2)O(2) and safely internalizing radicals through the ferric/ferryl pseudoperoxidase cycle.


Assuntos
Hemoglobina A/química , Hemoglobina A/metabolismo , Hemoglobina J/química , Hemoglobina J/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Óxidos N-Cíclicos , Ácido Cisteico/química , Dimerização , Globinas/química , Heme/química , Hemoglobina A/genética , Hemoglobina J/genética , Humanos , Técnicas In Vitro , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Estresse Oxidativo , Estabilidade Proteica , Estrutura Quaternária de Proteína , Subunidades Proteicas , Espectrometria de Massas por Ionização por Electrospray , Marcadores de Spin , Espectrometria de Massas em Tandem
5.
Redox Rep ; 25(1): 95-103, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33059548

RESUMO

The ß subunit substitutions, F41Y and K82D, in sickle cell hemoglobin (Hb) (ßE6 V) provides significant resistance to oxidative stress by shielding ßCys93 from the oxidizing ferryl heme. We evaluated the oxidative resistance of ßCys93 to hydrogen peroxide (H2O2) in α subunit mutations in ßE6 V (at both the putative and lateral contact regions) that included (1) αH20Q/ßE6 V; (2) αH50Q/ßE6 V; (3) αH20Q/H50Q/ßE6 V; (4) αH20R/ßE6 V; and (5) αH20R/H50Q/ßE6 V. Estimation by mass spectrometry of irreversible oxidation of ßCys93 to cysteic acid (CA) was unchanged or moderately increased in the single mutants harboring a H20Q or H50Q substitution when compared to control (ßE6 V). The introduction of Arg (R) singularly or in combination with Q enhanced the pseudoperoxidative cycle by slightly decreasing the ferryl in favor of ferrous and ferric species after treatment with H2O2. Higher rates for heme loss from the ferric forms of the Q species to the receptor high affinity recombinant apomyglobin were observed in contrast to the R mutants and control. Because of their improved solubility, a combination of Q and R substitutions together with mutations carrying redox active variants (F41Y/K82D) may provide dual antioxidant and antisickling targets in the design of gene therapy-based candidates.


Assuntos
Cisteína/genética , Hemoglobina Falciforme/química , Hemoglobina Falciforme/genética , Substituição de Aminoácidos , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Heme/química , Heme/genética , Hemoglobina Falciforme/metabolismo , Humanos , Peróxido de Hidrogênio/química , Focalização Isoelétrica , Espectrometria de Massas , Mutação , Oxirredução , Estresse Oxidativo , Estabilidade Proteica , Subunidades Proteicas
6.
JCI Insight ; 3(21)2018 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-30385713

RESUMO

The contribution of intracellular hemoglobin (Hb) oxidation to RBC-derived microparticle (MP) formation is poorly defined in sickle cell disease (SCD). Here we report that sickle Hb (HbS) oxidation, coupled with changes in cytosolic antioxidative proteins, is associated with membrane alterations and MP formation in homozygous Townes-sickle cell (Townes-SS) mice. Photometric and proteomic analyses confirmed the presence of high levels of Hb oxidation intermediates (ferric/ferryl) and consequent ß-globin posttranslational modifications, including the irreversible oxidation of ßCys93 and the ubiquitination of ßLys96 and ßLys145. This is the first report to our knowledge to link the UPS (via ubiquitinated Hb and other proteins) to oxidative stress. Ferryl Hb also induced complex formation with band 3 and RBC membrane proteins. Incubation of Townes-SS MPs with human endothelial cells caused greater loss of monolayer integrity, apoptotic activation, heme oxygenase-1 induction, and concomitant bioenergetic imbalance compared with control Townes-AA MPs. MPs obtained from Townes-SS mice treated with hydroxyurea produced fewer posttranslational Hb modifications. In vitro, hydroxyurea reduced the levels of ferryl Hb and shielded its target residue, ßCys93, by a process of S-nitrosylation. These mechanistic analyses suggest potential antioxidative therapeutic modalities that may interrupt MP heme-mediated pathophysiology in SCD patients.


Assuntos
Micropartículas Derivadas de Células/efeitos dos fármacos , Hemoglobinas/efeitos dos fármacos , Hidroxiureia/farmacologia , Anemia Falciforme/tratamento farmacológico , Animais , Antidrepanocíticos/farmacologia , Micropartículas Derivadas de Células/metabolismo , Células Endoteliais/efeitos dos fármacos , Metabolismo Energético , Hemoglobina Falciforme/efeitos dos fármacos , Hemoglobina Falciforme/metabolismo , Hemoglobinas/metabolismo , Humanos , Hidroxiureia/administração & dosagem , Camundongos/genética , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Proteômica
7.
J Am Soc Mass Spectrom ; 16(6): 916-25, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15907706

RESUMO

Stable isotope labeling with (18)O is a promising technique for obtaining both qualitative and quantitative information from a single differential protein expression experiment. The small 4 Da mass shift produced by incorporation of two molecules of (18)O, and the lack of available methods for automated quantification of large data sets has limited the use of this approach with electrospray ionization-ion trap (ESI-IT) mass spectrometers. In this paper, we describe a method of acquiring ESI-IT mass spectrometric data that provides accurate calculation of relative ratios of peptides that have been differentially labeled using(18)O. The method utilizes zoom scans to provide high resolution data. This allows for accurate calculation of (18)O/(16)O ratios for peptides even when as much as 50% of a (18)O labeled peptide is present as the singly labeled species. The use of zoom scan data also provides sufficient resolution for calculating accurate ratios for peptides of +3 and lower charge states. Sequence coverage is comparable to that obtained with data acquisition modes that use only MS and MS/MS scans. We have employed a newly developed analysis software tool, ZoomQuant, which allows for the automated analysis of large data sets. We show that the combination of zoom scan data acquisition and analysis using ZoomQuant provides calculation of isotopic ratios accurate to approximately 21%. This compares well with data produced from (18)O labeling experiments using time of flight (TOF) and Fourier transform-ion cyclotron resonance (FT-ICR) MS instruments.


Assuntos
Espectrometria de Massas/métodos , Software , Sequência de Aminoácidos , Animais , Cavalos , Humanos , Marcação por Isótopo , Dados de Sequência Molecular , Mioglobina/análise , Isótopos de Oxigênio , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Proteínas Tirosina Fosfatases/análise , Coelhos , Ratos , Reprodutibilidade dos Testes , Fator A de Crescimento do Endotélio Vascular/análise
8.
J Am Soc Mass Spectrom ; 16(3): 302-6, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15734322

RESUMO

The main goal of comparative proteomics is the quantitation of the differences in abundance of many proteins between two different biological samples in a single experiment. By differentially labeling the peptides from the two samples and combining them in a single analysis, relative ratios of protein abundance can be accurately determined. Protease catalyzed (18)O exchange is a simple method to differentially label peptides, but the lack of robust software tools to analyze the data from mass spectra of (18)O labeled peptides generated by common ion trap mass spectrometers has been a limitation. ZoomQuant is a stand-alone computational tool that analyzes the mass spectra of (18)O labeled peptides from ion trap instruments and determines relative abundance ratios between two samples. Starting with a filtered list of candidate peptides that have been successfully identified by Sequest, ZoomQuant analyzes the isotopic forms of the peptides using high-resolution zoom scan spectrum data. The theoretical isotope distribution is determined from the peptide sequence and is used to deconvolute the peak areas associated with the unlabeled, partially labeled, and fully labeled species. The ratio between the labeled and unlabeled peptides is then calculated using several different methods. ZoomQuant's graphical user interface allows the user to view and adjust the parameters for peak calling and quantitation and select which peptides should contribute to the overall abundance ratio calculation. Finally, ZoomQuant generates a summary report of the relative abundance of the peptides identified in the two samples.


Assuntos
Espectrometria de Massas/métodos , Peptídeos/análise , Software , Animais , Cavalos , Marcação por Isótopo , Mioglobina/análise , Isótopos de Oxigênio , Proteômica , Tripsina
9.
Toxicology ; 333: 89-99, 2015 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-25891524

RESUMO

Methemoglobin-forming drugs, such as sodium nitrite (NaNO2), may exacerbate oxidative toxicity under certain chronic or acute hemolytic settings. In this study, we evaluated markers of renal oxidative stress and injury in guinea pigs exposed to extracellular hemoglobin (Hb) followed by NaNO2 at doses sufficient to simulate clinically relevant acute methemoglobinemia. NaNO2 induced rapid and extensive oxidation of plasma Hb in this model. This was accompanied by increased renal expression of the oxidative response effectors nuclear factor erythroid 2-derived-factor 2 (Nrf-2) and heme oxygenase-1 (HO-1), elevated non-heme iron deposition, lipid peroxidation, interstitial inflammatory cell activation, increased expression of tubular injury markers kidney injury-1 marker (KIM-1) and liver-fatty acid binding protein (L-FABP), podocyte injury, and cell death. Importantly, these indicators of renal oxidative stress and injury were minimal or absent following infusion of Hb or NaNO2 alone. Together, these results suggest that the exposure to NaNO2 in settings associated with increased extracellular Hb may potentiate acute renal toxicity via processes that are independent of NaNO2 induced erythrocyte methemoglobinemia.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Hemoglobinas/toxicidade , Rim/efeitos dos fármacos , Metemoglobinemia/induzido quimicamente , Nitratos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Injúria Renal Aguda/sangue , Injúria Renal Aguda/patologia , Animais , Biomarcadores/metabolismo , Morte Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Proteínas de Ligação a Ácido Graxo/metabolismo , Cobaias , Heme Oxigenase-1/metabolismo , Hemoglobinas/administração & dosagem , Infusões Intravenosas , Rim/metabolismo , Rim/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Metemoglobina/metabolismo , Metemoglobinemia/sangue , Metemoglobinemia/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Nitratos/administração & dosagem , Oxirredução , Fatores de Tempo
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