Engineered mutations change the structure and stability of a virus-like particle
Jason D Fiedler1, Cody Higginson, Marisa L Hovlid
1Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States.
Biomacromolecules
|July 27, 2012
Summary
Disulfide linkages are key to the stability of bacteriophage Qβ virus-like particles (VLPs). Acidic conditions enhance VLP thermal stability, while mutations can create smaller VLPs.
Area of Science:
- Biochemistry
- Structural Biology
- Materials Science
Background:
- Bacteriophage Qβ coat protein (CP) self-assembles into highly stable T=3 icosahedral virus-like particles (VLPs).
- Understanding the molecular determinants of VLP stability is crucial for optimizing their applications.
- Current knowledge lacks specific identification of key stabilizing interactions within the Qβ VLP structure.
Purpose of the Study:
- To identify the molecular determinants of Qβ VLP stability.
- To explore manipulations for enhancing VLP material capabilities.
- To investigate the role of covalent dimers and primary structure in VLP stability.
Main Methods:
- Manipulating the CP primary structure to assess stabilizing interactions.
- Optimizing a procedure for incorporating fused CP subunits to control dimer formation.
- Introducing single point mutations in the CP.
Main Results:
- Disulfide linkages were confirmed as the most critical stabilizing elements for the capsid.
- Acidic conditions significantly improved VLP resistance to thermal degradation.
- Intradimer interactions were more vital for VLP assembly than interdimer interactions.
- A single point mutation led to the formation of smaller VLPs in three distinct structural forms.
Conclusions:
- Disulfide bonds are essential for Qβ VLP structural integrity.
- Acidic environments enhance the thermal stability of these virus-like particles.
- CP primary structure and dimer formation play significant roles in VLP assembly and stability.
- VLP structural plasticity can be modulated through targeted mutations.
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