Abstract
The proteasome is responsible for most intracellular protein degradation and is essential for cell survival. Previous research has shown that the proteasome can be inhibited by a number of oxidants, including 4-hydroxynonenal (HNE). The present study demonstrates that HNE rapidly inhibits the chymotrypsin-like activity of the 20S proteasome purified from liver. Subunits containing HNE-adducts were identified following 2D gel electrophoresis, Western immunoblotting, and analysis by MALDI-TOF MS. At a time when only the chymotrypsin-like activity was inhibited, the alpha 6/C2 subunit was uniquely modified. These results provide important molecular details regarding the catalytic site-specific inhibition of proteasome by HNE.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Aldehydes / metabolism*
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Aldehydes / pharmacology
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Amino Acid Sequence
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Animals
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Antioxidants / metabolism*
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Antioxidants / pharmacology
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Binding Sites
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Blotting, Western
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Catalysis
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Chymotrypsin / metabolism
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Cysteine Endopeptidases / isolation & purification
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Cysteine Endopeptidases / metabolism
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Cysteine Proteinase Inhibitors / metabolism*
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Cysteine Proteinase Inhibitors / pharmacology
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Electrophoresis, Gel, Two-Dimensional
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Kinetics
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Liver / drug effects
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Liver / enzymology
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Mass Spectrometry
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Molecular Sequence Data
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Peptide Mapping
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Proteasome Endopeptidase Complex / isolation & purification
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Proteasome Endopeptidase Complex / metabolism*
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Rats
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Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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Trypsin / metabolism
Substances
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Aldehydes
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Antioxidants
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Cysteine Proteinase Inhibitors
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Chymotrypsin
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Trypsin
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Cysteine Endopeptidases
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Proteasome Endopeptidase Complex
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4-hydroxy-2-nonenal