Probing the stability and mechanism for folding of the GrpE1-112 tetrameric deletion mutant of the GrpE protein from E. coli
| Autor: | Shirley M. Dehn, Kelby Okada, Andrew F. Mehl, Sarah Kurian |
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| Rok vydání: | 2012 |
| Předmět: |
Protein Folding
Circular dichroism Stereochemistry Biophysics medicine.disease_cause Biochemistry Protein Structure Secondary chemistry.chemical_compound Tetramer medicine Denaturation (biochemistry) Molecular Biology Escherichia coli Heat-Shock Proteins Sequence Deletion chemistry.chemical_classification Protein Stability Circular Dichroism Escherichia coli Proteins Cell Biology Amino acid Crystallography Monomer Models Chemical chemistry Urea Protein folding Protein Multimerization |
| Zdroj: | Biochemical and Biophysical Research Communications. 420:635-638 |
| ISSN: | 0006-291X |
| Popis: | Insight into the stability and folding of oligomeric proteins is essential to the understanding of protein folding, especially since the majority of proteins found in nature are oligomeric. A deletion mutant of the GrpE protein from Escherichia coli , that contains the first 112 residues (GrpE1-112) of 197 total, is an oligomeric protein forming a tetrameric structure. A four-helix bundle structure is formed via the interaction of an α-helix (22 amino acids in length) from each monomer. Using both thermal and chemical (urea) denaturation studies, the GrpE1-112 protein has rather low stability with a T m of unfolding of 37 °C, a C m (urea) of 1.3 M, and a Δ G unfolding of 8.4 kJ mol −1 . Investigation into the folding pathway using circular dichroism (CD) stopped-flow revealed a two step process with a fast first phase ( k refolding = 8.0 × 10 6 s −1 M −1 ) forming a multimeric intermediate that possesses significant α-helical content followed by a slow, first order, step forming the folded tetramer. |
| Databáze: | OpenAIRE |
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