SDS-resistant Active and Thermostable Dimers Are Obtained from the Dissociation of Homotetrameric β-Glycosidase from Hyperthermophilic Sulfolobus solfataricus in SDS
| Autor: | Ferdinando Febbraio, Pietro Amodeo, Fabrizio Gentile, Andrea Motta, Roberto Nucci, Francesco Picaro, Silvestro Formisano |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Chemistry
ved/biology Dimer Sulfolobus solfataricus ved/biology.organism_classification_rank.species Cell Biology Biochemistry Hyperthermophile Crystallography chemistry.chemical_compound Protein structure Tetramer Protein quaternary structure Molecular Biology Polyacrylamide gel electrophoresis Protein secondary structure |
| Zdroj: | Journal of Biological Chemistry. 277:44050-44060 |
| ISSN: | 0021-9258 |
| Popis: | β-Glycosidases are fundamental, widely conserved enzymes. Those from hyperthermophiles exhibit unusual stabilities toward various perturbants. Previous work with homotetrameric β-glycosidase from hyperthermophilic Sulfolobus solfataricus (M r 226,760) has shown that addition of 0.05–0.1% SDS was associated with minimal secondary structure perturbations and increased activity. This work addresses the effects of SDS on β-glycosidase quaternary structure. In 0.1–1% SDS, the enzyme was dimeric, as determined by Ferguson analysis of transverse-gradient polyacrylamide gels. The catalytic activity of the β-glycosidase dimer in SDS was determined by in-gel assay. A minor decrease of thermal stability in SDS was observed after exposure to temperatures up to 80 °C for 1 h. An analysis of β-glycosidase crystal structure showed different changes in solvent-accessible surface area on going from the tetramer to the two possible dimers (A-C and A-D). Energy minimization and molecular dynamics calculations showed that the A-C dimer, exhibiting the lowest exposed surface area, was more stabilized by a network of polar interactions. The charge distribution around the A-C interface was characterized by a local short range anisotropy, resulting in an unfavorable interaction with SDS. This paper provides a detailed description of an SDS-resistant inter-monomeric interface, which may help understand similar interfaces involved in important biological processes. |
| Databáze: | OpenAIRE |
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