Lindner, Robin A. and Carver, John A. and Ehrnsperger, Monika and Buchner, Johannes and Esposito, Gennaro and Behlke, Joachim and Lutsch, Gudrun and Kotlyarov, Alexey and Gaestel, Matthias (2000) Mouse Hsp25, a small heat shock protein - The role of its C-terminal extension in oligomerization and chaperone action. EUROPEAN JOURNAL OF BIOCHEMISTRY, 267 (7). pp. 1923-1932. ISSN 0014-2956
Full text not available from this repository. (Request a copy)Abstract
Under conditions of cellular stress, small heat shock proteins (sHsps), e.g. Hsp25, stabilize unfolding proteins and prevent their precipitation from solution. H-1 NMR spectroscopy has shown that mammalian sHsps possess short, polar and highly flexible C-terminal extensions. A mutant of mouse Hsp25 without this extension has been constructed. CD spectroscopy reveals some differences in secondary and tertiary structure between this mutant and the wild-type protein but analytical ultracentrifugation and electron microscopy show that the proteins have very similar oligomeric masses and quaternary structures. The mutant shows chaperone ability comparable to that of wild-type Hsp25 in a thermal aggregation assay using citrate synthase, but does not stabilize alpha-lactalbumin against precipitation following reduction with dithiothreitol. The accessible hydrophobic surface of the mutant protein is less than that of the wild-type protein and the mutant is also less stable at elevated temperature. H-1 NMR spectroscopy reveals that deletion of the C-terminal extension of Hsp25 leads to induction of extra C-terminal flexibility in the molecule. Monitoring complex formation between Hsp25 and dithiothreitol-reduced alpha-lactalbumin by H-1 NMR spectroscopy indicates that the C-terminal extension of Hsp25 retains its flexibility during this interaction. Overall, these data suggest that a highly flexible C-terminal extension in mammalian sHsps is required for full chaperone activity.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | BOVINE ALPHA-CRYSTALLIN; H-1-NMR SPECTROSCOPY; DISULFIDE BOND; AMINO-ACIDS; DOMAIN; LACTALBUMIN; BINDING; SURFACE; flexibility; Hsp25; molecular chaperone; small heat shock protein; spectroscopy |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 17 May 2022 07:17 |
| Last Modified: | 17 May 2022 07:17 |
| URI: | https://pred.uni-regensburg.de/id/eprint/42615 |
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