| Autor: |
Yulia V. Pivovarova, Alexander Yakimov, Adam Groves, Nikolai R. Skrynnikov, Sergei A. Izmailov, Tairan Yuwen, Ivan S. Podkorytov, Sevastyan O. Rabdano |
| Rok vydání: |
2016 |
| Předmět: |
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| Zdroj: |
Biophysical Journal. 110(3) |
| ISSN: |
0006-3495 |
| DOI: |
10.1016/j.bpj.2015.11.1167 |
| Popis: |
In the presence of reactive oxygen species, proteins with solvent-exposed cysteine side chains readily undergo disulfide-mediated dimerization (oligomerization). Disulfide bridges are fairly short linkages that bring into close contact protein surfaces which have not evolved to complement each other. The resulting random pairing of surface residues as occurs at the protein-protein interfaces is likely to have an appreciable destabilizing effect on the protein structure. To test this hypothesis we have studied the effect of oxidative stress (modeled by hydrogen peroxide treatment) on the second RNA-recognition motif from the neuropathological protein TDP-43. 1H-15N HSQC titration and H/D exchange experiments confirm that formation of disulfide-bonded dimers leads to a loss of protein stability. In addition, temperature-dependent 1H spectroscopy indicates that dimeric RRM2 has lower melting temperature. As a negative control we have characterized the sample of RRM2 with C244S mutation, which does not form intermolecular disulfide bonds. The destabilizing effect of adventitious disulfide bridges has also been investigated by MD simulations of the RRM2 dimers. The simulations were conducted in explicit solvent under Amber 14SB force field; the data were used to predict HN solvent exchange protection factors, thus paving the way for comparison with the experimental results. The loss of structural stability caused by disulfide bonding under the conditions of oxidative stress may lead to increased proteolytic degradation of the RRM2 domain, resulting in formation of C-terminal fragments of TDP-43, which have been viewed as one of the causative factors in genesis of the neuronal inclusion bodies.1[1] Zhang, Y. J. et al. Proc. Natl. Acad. Sci. USA 106:7607-7612 (2009). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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