Haptoglobin Binding Stabilizes Hemoglobin Ferryl Iron and the Globin Radical on Tyrosine beta 145

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Haptoglobin Binding Stabilizes Hemoglobin Ferryl Iron and the Globin Radical on Tyrosine beta 145. / Cooper, Chris E.; Schaer, Dominik J.; Buehler, Paul W.; Wilson, Michael T.; Reeder, Brandon J.; Silkstone, Gary; Svistunenko, Dimitri A.; Bülow, Leif; Alayash, Abdu I.

I: Antioxidants & Redox Signaling, Vol. 18, Nr. 17, 2013, s. 2264-2273.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

Cooper, CE, Schaer, DJ, Buehler, PW, Wilson, MT, Reeder, BJ, Silkstone, G, Svistunenko, DA, Bülow, L & Alayash, AI 2013, 'Haptoglobin Binding Stabilizes Hemoglobin Ferryl Iron and the Globin Radical on Tyrosine beta 145', Antioxidants & Redox Signaling, vol. 18, nr. 17, s. 2264-2273. https://doi.org/10.1089/ars.2012.4547

APA

Cooper, C. E., Schaer, D. J., Buehler, P. W., Wilson, M. T., Reeder, B. J., Silkstone, G., Svistunenko, D. A., Bülow, L., & Alayash, A. I. (2013). Haptoglobin Binding Stabilizes Hemoglobin Ferryl Iron and the Globin Radical on Tyrosine beta 145. Antioxidants & Redox Signaling, 18(17), 2264-2273. https://doi.org/10.1089/ars.2012.4547

CBE

Cooper CE, Schaer DJ, Buehler PW, Wilson MT, Reeder BJ, Silkstone G, Svistunenko DA, Bülow L, Alayash AI. 2013. Haptoglobin Binding Stabilizes Hemoglobin Ferryl Iron and the Globin Radical on Tyrosine beta 145. Antioxidants & Redox Signaling. 18(17):2264-2273. https://doi.org/10.1089/ars.2012.4547

MLA

Vancouver

Author

Cooper, Chris E. ; Schaer, Dominik J. ; Buehler, Paul W. ; Wilson, Michael T. ; Reeder, Brandon J. ; Silkstone, Gary ; Svistunenko, Dimitri A. ; Bülow, Leif ; Alayash, Abdu I. / Haptoglobin Binding Stabilizes Hemoglobin Ferryl Iron and the Globin Radical on Tyrosine beta 145. I: Antioxidants & Redox Signaling. 2013 ; Vol. 18, Nr. 17. s. 2264-2273.

RIS

TY - JOUR

T1 - Haptoglobin Binding Stabilizes Hemoglobin Ferryl Iron and the Globin Radical on Tyrosine beta 145

AU - Cooper, Chris E.

AU - Schaer, Dominik J.

AU - Buehler, Paul W.

AU - Wilson, Michael T.

AU - Reeder, Brandon J.

AU - Silkstone, Gary

AU - Svistunenko, Dimitri A.

AU - Bülow, Leif

AU - Alayash, Abdu I.

PY - 2013

Y1 - 2013

N2 - Aim: Hemoglobin (Hb) becomes toxic when released from the erythrocyte. The acute phase protein haptoglobin (Hp) binds avidly to Hb and decreases oxidative damage to Hb itself and to the surrounding proteins and lipids. However, the molecular mechanism underpinning Hp protection is to date unclear. The aim of this study was to use electron paramagnetic resonance (EPR) spectroscopy, stopped flow optical spectrophotometry, and site-directed mutagenesis to explore the mechanism and specifically the role of specific tyrosine residues in this protection. Results: Following peroxide challenge Hb produces reactive oxidative intermediates in the form of ferryl heme and globin free radicals. Hp binding increases the steady state level of ferryl formation during Hb-catalyzed lipid peroxidation, while at the same time dramatically inhibiting the overall reaction rate. This enhanced ferryl stability is also seen in the absence of lipids and in the presence of external reductants. Hp binding is not accompanied by a decrease in the pK of ferryl protonation; the protonated ferryl species still forms, but is intrinsically less reactive. Ferryl stabilization is accompanied by a significant increase in the concentration of the peroxide-induced tyrosine free radical. EPR spectral parameters and mutagenesis studies suggest that this radical is located on tyrosine 145, the penultimate C-terminal amino acid on the beta Hb subunit. Innovation: Hp binding decreases both the ferryl iron and free radical reactivity of Hb. Conclusion: Hp protects against Hb-induced damage in the vasculature, not by preventing the primary reactivity of heme oxidants, but by rendering the resultant protein products less damaging. Antioxid. Redox Signal. 18, 2264-2273.

AB - Aim: Hemoglobin (Hb) becomes toxic when released from the erythrocyte. The acute phase protein haptoglobin (Hp) binds avidly to Hb and decreases oxidative damage to Hb itself and to the surrounding proteins and lipids. However, the molecular mechanism underpinning Hp protection is to date unclear. The aim of this study was to use electron paramagnetic resonance (EPR) spectroscopy, stopped flow optical spectrophotometry, and site-directed mutagenesis to explore the mechanism and specifically the role of specific tyrosine residues in this protection. Results: Following peroxide challenge Hb produces reactive oxidative intermediates in the form of ferryl heme and globin free radicals. Hp binding increases the steady state level of ferryl formation during Hb-catalyzed lipid peroxidation, while at the same time dramatically inhibiting the overall reaction rate. This enhanced ferryl stability is also seen in the absence of lipids and in the presence of external reductants. Hp binding is not accompanied by a decrease in the pK of ferryl protonation; the protonated ferryl species still forms, but is intrinsically less reactive. Ferryl stabilization is accompanied by a significant increase in the concentration of the peroxide-induced tyrosine free radical. EPR spectral parameters and mutagenesis studies suggest that this radical is located on tyrosine 145, the penultimate C-terminal amino acid on the beta Hb subunit. Innovation: Hp binding decreases both the ferryl iron and free radical reactivity of Hb. Conclusion: Hp protects against Hb-induced damage in the vasculature, not by preventing the primary reactivity of heme oxidants, but by rendering the resultant protein products less damaging. Antioxid. Redox Signal. 18, 2264-2273.

U2 - 10.1089/ars.2012.4547

DO - 10.1089/ars.2012.4547

M3 - Article

C2 - 22702311

VL - 18

SP - 2264

EP - 2273

JO - Antioxidants and Redox Signaling

JF - Antioxidants and Redox Signaling

SN - 1557-7716

IS - 17

ER -