The Two-Stage Process of the Heat Shock Protein 90 Thermal Denaturation: Effect of Calcium and Magnesium
| Autor: | Vincent Peyrot, I.I. Protasevich, Philipp O. Tsvetkov, Robert Gilli, Claudette Briand, Cyrille Garnier, Alexander A. Makarov, Vladimir M. Lobachov |
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| Rok vydání: | 1998 |
| Předmět: |
Isothermal microcalorimetry
Protein Denaturation Circular dichroism Swine Chemistry Magnesium Dimer Temperature Biophysics chemistry.chemical_element Cell Biology Calcium Biochemistry chemistry.chemical_compound Crystallography Heat shock protein polycyclic compounds Animals Denaturation (biochemistry) HSP90 Heat-Shock Proteins Molecular Biology Thermostability |
| Zdroj: | Biochemical and Biophysical Research Communications. 249:197-201 |
| ISSN: | 0006-291X |
| DOI: | 10.1006/bbrc.1998.9108 |
| Popis: | Scanning microcalorimetry, native PAG electrophoresis, and circular dichroism were used to characterize thermal denaturation and oligomerization of heat shock protein 90 (hsp90) and the calcium and magnesium effect on these processes. The calorimetric curve of the hsp90 dimer consists of two transitions centered at 53.8 and 63.1 degrees C. Using specific ligand geldanamycin, we have found that N-terminal domains in the hsp90 dimer are melted independently in the lower-temperature peak, while the higher-temperature one comprises unfolding of two non-interacting parts of the middle domains and dimerization region. Unfolding of the N-terminal domain gives start to oligomerization of dimers; oligomers consist of dimers not dissociating upon denaturation. Calcium and magnesium strongly decrease the hsp90 thermostability and thereby cause oligomerization at lower temperature. We suggest that calcium affects the hsp90 oligomerization, known to be important for its chaperone activity, by shifting the unfolding temperature of the hsp90 N-terminal domain close to the heat shock temperature range. |
| Databáze: | OpenAIRE |
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