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Peroxynitrite-Mediated Structural Changes in Histone H2A: Biochemical and Biophysical Analysis
Md Asad Khan1, Md Faiz Akram1, Khursheed Alam2
1Faculty of Dentistry, Jamia Millia Islamia, New Delhi-110025, India.
Protein and Peptide Letters
|April 29, 2020
Summary
Peroxynitrite exposure increases dityrosine in H2A histone, causing structural changes. This oxidative damage to histone H2A indicates potential roles in aging and neurodegenerative diseases.
Area of Science:
- Biochemistry
- Molecular Biology
- Protein Chemistry
Background:
- Peroxynitrite, a potent nitrating and oxidizing agent, arises from nitric oxide and superoxide radicals.
- Histone H2A, a core component of nucleosomes, packages DNA and is susceptible to oxidative and nitrating damage.
Purpose of the Study:
- To investigate the effects of peroxynitrite-induced nitration and dinitration on histone H2A.
- To identify peroxynitrite-mediated structural modifications in H2A as potential biomarkers.
Main Methods:
- Assessment of peroxynitrite-mediated nitration and dinitration in H2A histone.
- Utilized various biophysical techniques to analyze structural changes.
Main Results:
- Elevated dityrosine content was observed in H2A histone treated with peroxynitrite.
- Peroxynitrite modification led to decreased fluorescence, altered FT-IR spectra, increased hydrodynamic size, and loss of secondary/tertiary structure in H2A, resulting in partial unfolding.
Conclusions:
- Histone H2A undergoes significant conformational and structural alterations due to peroxynitrite-induced nitrosative and oxidative stress.
- These findings suggest H2A modification as a marker for oxidative stress, aging, and neurodegenerative conditions.
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