Related Experiment Videos
Conformational polymorphism, stability and aggregation in spider dragline silks proteins.
Cedric Dicko1, David Knight, John M Kenney
1Department of Zoology, Oxford University, Oxford OX1 3PS, UK. cedric.dicko@zoo.ox.ac.uk
International Journal of Biological Macromolecules
|August 17, 2005
Summary
Spider silk proteins undergo structural changes during spinning. Detergents and solvents influence this transition, promoting either beta-sheet or helical structures in spidroin.
Area of Science:
- Biochemistry
- Materials Science
- Protein Chemistry
Background:
- Spider silk formation involves a complex structural transition from disordered to beta-sheet rich protein structures.
- This hydrophobic conversion is crucial for spider silk's unique properties.
Purpose of the Study:
- To investigate the effects of detergents and solvent polarity on the secondary structure of native spidroin.
- To test the hypothesis that hydrophobic conversion drives the structural transition in spider silk proteins.
Main Methods:
- Monitoring secondary structure transitions in dilute spidroin solutions.
- Utilizing cationic (DOTAC) and anionic detergents.
- Employing a series of alcohols (HFIP, TFE, MeOH, EtOH, IsoP) to alter solvent polarity.
Main Results:
- Detergents induced transitions to beta-sheet or helical states, influenced by head charge and tail length.
- High polarity solvents (HFIP, TFE) promoted stable helical forms.
- Lower polarity solvents (MeOH, EtOH, IsoP) led to kinetically driven beta-sheet formation.
Conclusions:
- Both detergent properties and solvent polarity significantly control spidroin secondary structure.
- The findings provide insights into the mechanisms of spider silk formation and protein structural dynamics.