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Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design

Hemoglobin (Hb)-based oxygen carriers (HBOC) have been engineered to replace or augment the oxygen-carrying capacity of erythrocytes. However, clinical results have generally been disappointing due to adverse side effects linked to intrinsic heme-mediated oxidative toxicity and nitric oxide (NO) sca...

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Autores principales: Silkstone, Gary G.A., Silkstone, Rebecca S., Wilson, Michael T., Simons, Michelle, Bülow, Leif, Kallberg, Kristian, Ratanasopa, Khuanpiroon, Ronda, Luca, Mozzarelli, Andrea, Reeder, Brandon J., Cooper, Chris E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Portland Press Ltd. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095908/
https://www.ncbi.nlm.nih.gov/pubmed/27470146
http://dx.doi.org/10.1042/BCJ20160243
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author Silkstone, Gary G.A.
Silkstone, Rebecca S.
Wilson, Michael T.
Simons, Michelle
Bülow, Leif
Kallberg, Kristian
Ratanasopa, Khuanpiroon
Ronda, Luca
Mozzarelli, Andrea
Reeder, Brandon J.
Cooper, Chris E.
author_facet Silkstone, Gary G.A.
Silkstone, Rebecca S.
Wilson, Michael T.
Simons, Michelle
Bülow, Leif
Kallberg, Kristian
Ratanasopa, Khuanpiroon
Ronda, Luca
Mozzarelli, Andrea
Reeder, Brandon J.
Cooper, Chris E.
author_sort Silkstone, Gary G.A.
collection PubMed
description Hemoglobin (Hb)-based oxygen carriers (HBOC) have been engineered to replace or augment the oxygen-carrying capacity of erythrocytes. However, clinical results have generally been disappointing due to adverse side effects linked to intrinsic heme-mediated oxidative toxicity and nitric oxide (NO) scavenging. Redox-active tyrosine residues can facilitate electron transfer between endogenous antioxidants and oxidative ferryl heme species. A suitable residue is present in the α-subunit (Y42) of Hb, but absent from the homologous position in the β-subunit (F41). We therefore replaced this residue with a tyrosine (βF41Y, Hb Mequon). The βF41Y mutation had no effect on the intrinsic rate of lipid peroxidation as measured by conjugated diene and singlet oxygen formation following the addition of ferric(met) Hb to liposomes. However, βF41Y significantly decreased these rates in the presence of physiological levels of ascorbate. Additionally, heme damage in the β-subunit following the addition of the lipid peroxide hydroperoxyoctadecadieoic acid was five-fold slower in βF41Y. NO bioavailability was enhanced in βF41Y by a combination of a 20% decrease in NO dioxygenase activity and a doubling of the rate of nitrite reductase activity. The intrinsic rate of heme loss from methemoglobin was doubled in the β-subunit, but unchanged in the α-subunit. We conclude that the addition of a redox-active tyrosine mutation in Hb able to transfer electrons from plasma antioxidants decreases heme-mediated oxidative reactivity and enhances NO bioavailability. This class of mutations has the potential to decrease adverse side effects as one component of a HBOC product.
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spelling pubmed-50959082016-11-08 Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design Silkstone, Gary G.A. Silkstone, Rebecca S. Wilson, Michael T. Simons, Michelle Bülow, Leif Kallberg, Kristian Ratanasopa, Khuanpiroon Ronda, Luca Mozzarelli, Andrea Reeder, Brandon J. Cooper, Chris E. Biochem J Research Articles Hemoglobin (Hb)-based oxygen carriers (HBOC) have been engineered to replace or augment the oxygen-carrying capacity of erythrocytes. However, clinical results have generally been disappointing due to adverse side effects linked to intrinsic heme-mediated oxidative toxicity and nitric oxide (NO) scavenging. Redox-active tyrosine residues can facilitate electron transfer between endogenous antioxidants and oxidative ferryl heme species. A suitable residue is present in the α-subunit (Y42) of Hb, but absent from the homologous position in the β-subunit (F41). We therefore replaced this residue with a tyrosine (βF41Y, Hb Mequon). The βF41Y mutation had no effect on the intrinsic rate of lipid peroxidation as measured by conjugated diene and singlet oxygen formation following the addition of ferric(met) Hb to liposomes. However, βF41Y significantly decreased these rates in the presence of physiological levels of ascorbate. Additionally, heme damage in the β-subunit following the addition of the lipid peroxide hydroperoxyoctadecadieoic acid was five-fold slower in βF41Y. NO bioavailability was enhanced in βF41Y by a combination of a 20% decrease in NO dioxygenase activity and a doubling of the rate of nitrite reductase activity. The intrinsic rate of heme loss from methemoglobin was doubled in the β-subunit, but unchanged in the α-subunit. We conclude that the addition of a redox-active tyrosine mutation in Hb able to transfer electrons from plasma antioxidants decreases heme-mediated oxidative reactivity and enhances NO bioavailability. This class of mutations has the potential to decrease adverse side effects as one component of a HBOC product. Portland Press Ltd. 2016-10-01 2016-09-27 /pmc/articles/PMC5095908/ /pubmed/27470146 http://dx.doi.org/10.1042/BCJ20160243 Text en © 2016 The Author(s) https://creativecommons.org/licenses/by/4.0/This is an open access article published by Portland Press Limited on behalf of the Biochemical Society and distributed under the Creative Commons Attribution License 4.0 (CC BY) (https://creativecommons.org/licenses/by/4.0) .
spellingShingle Research Articles
Silkstone, Gary G.A.
Silkstone, Rebecca S.
Wilson, Michael T.
Simons, Michelle
Bülow, Leif
Kallberg, Kristian
Ratanasopa, Khuanpiroon
Ronda, Luca
Mozzarelli, Andrea
Reeder, Brandon J.
Cooper, Chris E.
Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design
title Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design
title_full Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design
title_fullStr Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design
title_full_unstemmed Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design
title_short Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design
title_sort engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095908/
https://www.ncbi.nlm.nih.gov/pubmed/27470146
http://dx.doi.org/10.1042/BCJ20160243
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