The reactions of hydropersulfides (RSSH) with myoglobin

https://doi.org/10.1016/j.abb.2020.108391Get rights and content
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Highlights

  • Hydropersulfides are capable of readily reducing ferric heme proteins to the ferrous forms.

  • Hydropersulfides are good reducing agents similar to ascorbate and/or hydroxylamine.

  • Dioxygen-binding heme proteins are capable of catalytically degrading hydropersulfides.

  • Hydropersulfides are capable of reacting with myoglobin to give a sulfurated sulfheme species.

Abstract

Hydropersulfides are reported to be good biological reductants, superior to thiols and akin to selenols. As such, they have been previously shown to reduce metalloproteins such as ferric myoglobin and ferric cytochrome c to their ferrous forms under conditions where little or no reduction from corresponding thiols is observed. Not surprisingly, the reduction of ferric myoglobin to ferrous myoglobin under aerobic conditions results in the generation of oxymyoglobin (dioxygen bound ferrous myoglobin). Previous studies have demonstrated that oxymyoglobin can also act as an oxidant with highly reducing species such as hydroxylamine and ascorbate. Considering the reducing properties of hydropersulfides, it is possible that they can also react with oxymyoglobin similarly to hydroxylamine or ascorbate. Herein, this reaction is examined and indeed hydropersulfides are found to react with oxymyoglobin similarly to other reducing species leading to a fleeting ferric myoglobin which is rapidly reduced to the ferrous form also by hydropersulfide.

Keywords

Hydropersulfides
Myoglobin
Hydrogen sulfide
Polysulfides
Sulfheme

Abbreviations

RSSH
hydropersulfide
RSSR
disulfide
RSOH
sulfenic acid
RSNO
S-nitrosothiol
MCPD
methoxycarbonyl penicillamne disulfide
DIP
diazenedicarboxyic acid bis-N′-methylpiperazinide
FeIIIMb
ferric myoglobin
O2FeIIMb
oxymyoglobin
DTPA
diethylenetriamine pentaacetic acid
HPE-IAM
β-(4-hydroxyphenyl)ethyl iodoacetamide
UPLC-MS
ultra-performance liquid chromatography mass spectrometry
RSSSR
trisulfide
RSSSSR
tetrasulfide
AH
ascorbate
A·-
ascorbyl radical anion
FeIIICyt c
ferric cytochrome c
FeIICyt c
ferrous cytochrome c

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