Cargando…
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...
Autores principales: | , , , , , , , , , , |
---|---|
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 |
_version_ | 1782465375027331072 |
---|---|
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. |
format | Online Article Text |
id | pubmed-5095908 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Portland Press Ltd. |
record_format | MEDLINE/PubMed |
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 |
work_keys_str_mv | AT silkstonegaryga engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT silkstonerebeccas engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT wilsonmichaelt engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT simonsmichelle engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT bulowleif engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT kallbergkristian engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT ratanasopakhuanpiroon engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT rondaluca engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT mozzarelliandrea engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT reederbrandonj engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign AT cooperchrise engineeringtyrosineelectrontransferpathwaysdecreasesoxidativetoxicityinhemoglobinimplicationsforbloodsubstitutedesign |