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Updated: Jun 3, 2026
14:32
Deacetylation Assays to Unravel the Interplay between Sirtuins (SIRT2) and Specific Protein-substrates
Published on: February 27, 2016
4-Hydroxynonenal inhibits SIRT3 via thiol-specific modification.
Kristofer S Fritz1, James J Galligan, Rebecca L Smathers
1Department of Pharmaceutical Sciences, Graduate Program in Toxicology, School of Pharmacy, University of Colorado Denver, Aurora, USA.
Chemical Research in Toxicology
|April 1, 2011
Summary
Lipid peroxidation product 4-hydroxynonenal (4-HNE) inhibits mitochondrial sirtuin 3 (SIRT3) deacetylase activity by binding to a critical cysteine residue. This modification alters SIRT3 conformation, impacting alcoholic liver disease pathogenesis.
Area of Science:
- Biochemistry
- Molecular Biology
- Cellular Signaling
Background:
- 4-Hydroxynonenal (4-HNE) is a key product of lipid peroxidation involved in cellular signaling and protein modification.
- Elevated protein carbonylation, particularly of sirtuin 3 (SIRT3), is observed in alcoholic liver disease (ALD).
- Mechanisms underlying mitochondrial protein hyperacetylation in chronic ethanol consumption remain unclear.
Purpose of the Study:
- To investigate the impact of in vivo 4-HNE modification on SIRT3 deacetylase activity.
- To elucidate the mechanisms of mitochondrial protein hyperacetylation in a mouse model of chronic ethanol consumption.
- To characterize the covalent modification of SIRT3 by 4-HNE and its functional consequences.
Main Methods:
- Analysis of liver mitochondrial extracts from ethanol-consuming mice.
- Tandem mass spectrometry to identify and characterize 4-HNE modification sites on SIRT3.
- Computational molecular modeling and docking studies to assess conformational changes and binding affinities.
Main Results:
- A significant increase in protein carbonylation of SIRT3 was observed in ethanol-fed mice.
- 4-HNE covalently modifies rSIRT3 at Cys(280), a zinc-binding residue, inhibiting its deacetylase activity.
- Molecular modeling revealed 4-HNE induces allosteric inhibition of SIRT3 activity by altering the zinc-binding domain conformation.
Conclusions:
- 4-HNE adduction to SIRT3 at Cys(280) leads to thiol-specific allosteric inhibition of its activity.
- This inhibition contributes to altered mitochondrial protein acetylation observed in alcoholic liver disease.
- The findings provide mechanistic insights into SIRT3 dysfunction in the context of chronic ethanol ingestion.
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