Micellar refolding of coiled-coil honeybee silk proteins

Walker, Andrew A., Warden, Andrew C., Trueman, Holly E., Weisman, Sarah and Sutherland, Tara D. (2013) Micellar refolding of coiled-coil honeybee silk proteins. Journal of Materials Chemistry B, 1 30: 3644-3651. doi:10.1039/c3tb20611d


Author Walker, Andrew A.
Warden, Andrew C.
Trueman, Holly E.
Weisman, Sarah
Sutherland, Tara D.
Title Micellar refolding of coiled-coil honeybee silk proteins
Journal name Journal of Materials Chemistry B   Check publisher's open access policy
ISSN 2050-7518
2050-7518
Publication date 2013-08-14
Year available 2013
Sub-type Article (original research)
DOI 10.1039/c3tb20611d
Open Access Status Not Open Access
Volume 1
Issue 30
Start page 3644
End page 3651
Total pages 8
Place of publication Cambridge, United Kingdom
Publisher R S C Publications
Collection year 2014
Language eng
Subject 1600 Chemistry
2204 Religion and Religious Studies
2700 Medicine
2500 Materials Science
Abstract There is growing interest in materials generated from coiled coil proteins for medical applications. In this study we describe controlled micellar refolding of coiled coil honeybee silk proteins using the detergent SDS. Circular dichroism and dynamic light scattering experiments demonstrate that micellar SDS promotes folding of randomly coiled honeybee silk proteins into isolated α-helices, and that removal of detergent micelles, or addition of salt, leads to coiled coil formation. Comparative molecular dynamics simulations of protein helices, with and without SDS, have allowed us to characterize detergent-protein interactions and propose a mechanism of protein folding. In the presence of micellar detergent, hydrophobic residues are associated with the detergent tail groups within the micelles whereas hydrophilic residues are paired with the detergent head-groups on the micelle's surface. These detergent-protein interactions prevent residue-residue interactions and allow the protein to fold according to the natural tendency of individual residues. From this condition, when hydrophobic residue-micellar interactions are reduced by lowering detergent levels to below the critical micelle concentration (CMC) or by using salt to increase detergent packing in micelles and thereby excluding the protein from the interior, the proteins fold into coiled coils. We propose that under low SDS conditions, hydrophobic-monomeric SDS tail-group and hydrophilic-monomeric head-group interactions (low SDS conditions) or hydrophilic-micellar SDS head-group interactions (high salt conditions) stabilize a transient α-helix intermediate in coiled coil folding. The folding pathway constitutes a new kind of micellar refolding, which may be profitably employed to refold other proteins rich in coiled coils.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Non HERDC
Institute for Molecular Bioscience - Publications
 
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