Formation of high-order oligomers by a hyperthemostable Fe-superoxide dismutase (tcSOD)
| Autor: | Yong-Bin Yan, Zhiyang Dong, Sha Wang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Protein Folding
Protein Denaturation Agarose Gel Chromatography lcsh:Medicine Enzyme Purification Protein aggregation Biochemistry Polyacrylamide Gel Electrophoresis Protein structure Enzyme Stability Native state Recombinant Protein Purification lcsh:Science Dynamic equilibrium Gel Electrophoresis Multidisciplinary Chemistry Chromatographic Techniques Enzyme structure Recombinant Proteins Enzymes Protein Misfolding Denaturation Dismutases Thermodynamics Research Article Protein Structure Protein Purification Size-Exclusion Chromatography Research and Analysis Methods Protein–protein interaction Accessible surface area Electrophoretic Techniques Multienzyme Complexes Column Chromatography Affinity Purification Protein Interaction Domains and Motifs Molecular Biology Techniques Molecular Biology Superoxide Dismutase Affinity Chromatography lcsh:R Biology and Life Sciences Proteins Metal Chelate Affinity Chromatography Protein Aggregation Amino Acid Substitution Helix Enzyme Structure Biophysics Enzymology lcsh:Q Protein Multimerization Purification Techniques |
| Zdroj: | PLoS ONE, Vol 9, Iss 10, p e109657 (2014) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | Hyperthermostable proteins are highly resistant to various extreme conditions. Many factors have been proposed to contribute to their ultrahigh structural stability. Some thermostable proteins have larger oligomeric size when compared to their mesophilic homologues. The formation of compact oligomers can minimize the solvent accessible surface area and increase the changes of Gibbs free energy for unfolding. Similar to mesophilic proteins, hyperthermostable proteins also face the problem of unproductive aggregation. In this research, we investigated the role of high-order oligomerization in the fight against aggregation by a hyperthermostable superoxide dismutase identified from Tengchong, China (tcSOD). Besides the predominant tetramers, tcSOD could also form active high-order oligomers containing at least eight subunits. The dynamic equilibrium between tetramers and high-order oligomers was not significantly affected by pH, salt concentration or moderate temperature. The secondary and tertiary structures of tcSOD remained unchanged during heating, while cross-linking experiments showed that there were conformational changes or structural fluctuations at high temperatures. Mutational analysis indicated that the last helix at the C-terminus was involved in the formation of high-order oligomers, probably via domain swapping. Based on these results, we proposed that the reversible conversion between the active tetramers and high-order oligomers might provide a buffering system for tcSOD to fight against the irreversible protein aggregation pathway. The formation of active high-order oligomers not only increases the energy barrier between the native state and unfolded/aggregated state, but also provides the enzyme the ability to reproduce the predominant oligomers from the active high-order oligomers. |
| Databáze: | OpenAIRE |
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