The elongation factors (EF-Tu/EF-1 alpha) are universal proteins, involved in protein biosynthesis. A detailed characterization of the stability against temperature of SsEF-1 alpha, a three-domain protein isolated from the hyperthermophilic archaeon Sulfolobus solfataricus is presented. Thermal denaturation of both the GDP-bound (SsEF-1 alpha*.GDP) and the ligand-free (nfSsEF-1 alpha) forms was investigated by means of circular dichroism and fluorescence measurements, over the 4.0-7.5 pH interval. Data indicate that the unfolding process is cooperative with no intermediate species and that the few inter-domain contacts identified in the crystal structure of SsEF-1 alpha play a role also at high temperatures. Finally, it is shown that the enzyme exhibits two different interchangeable thermally denatured states, depending on pH.
Titolo: | Stability against temperature of Sulfolobus solfataricus elongation factor 1alpha, a multi-domain protein | |
Autori: | ||
Data di pubblicazione: | 2008 | |
Rivista: | ||
Abstract: | The elongation factors (EF-Tu/EF-1 alpha) are universal proteins, involved in protein biosynthesis. A detailed characterization of the stability against temperature of SsEF-1 alpha, a three-domain protein isolated from the hyperthermophilic archaeon Sulfolobus solfataricus is presented. Thermal denaturation of both the GDP-bound (SsEF-1 alpha*.GDP) and the ligand-free (nfSsEF-1 alpha) forms was investigated by means of circular dichroism and fluorescence measurements, over the 4.0-7.5 pH interval. Data indicate that the unfolding process is cooperative with no intermediate species and that the few inter-domain contacts identified in the crystal structure of SsEF-1 alpha play a role also at high temperatures. Finally, it is shown that the enzyme exhibits two different interchangeable thermally denatured states, depending on pH. | |
Handle: | http://hdl.handle.net/11367/20832 | |
Appare nelle tipologie: | 1.1 Articolo in rivista |