Deciphering the Thermal Stability of Bacteriophage MS2-Derived Virus-like Particle and Its Engineered Variant

Area of Science:

• Biophysics
• Structural Biology
• Virology

Background:

• MS2 virus-like particles (VLPs) are essential tools in biomedical research for studying viral assembly, vaccine development, and drug delivery.
• Engineered mini MS2 VLPs offer improved serum stability and tissue penetration for enhanced therapeutic applications.
• The thermal stability and heat-induced disassembly mechanisms of MS2 VLPs remain largely uncharacterized.

Purpose of the Study:

• To investigate the thermal stability of wild-type (WT) MS2 VLPs and engineered mini MS2 VLPs.
• To elucidate the sequential process of heat-induced disassembly in MS2 VLPs.
• To understand the role of intersubunit and protein-nucleic acid interactions in VLP thermal stability.

Main Methods:

• Differential Scanning Calorimetry (DSC) to determine capsid melting temperatures (Tm).
• Circular Dichroism (CD) spectroscopy to monitor structural changes upon heating.
• Analysis of thermal unfolding pathways for both WT and mini MS2 VLPs.

Main Results:

• Mini MS2 VLPs exhibit a significantly higher melting temperature (Tm) compared to WT MS2 VLPs.
• Thermal unfolding of MS2 VLPs proceeds through a defined sequence: destabilization, nucleic acid exposure, and disassembly.
• The enhanced stability of mini MS2 VLPs may be linked to a smaller interdimer angle.

Conclusions:

• MS2 VLP thermal stability is dependent on structural integrity and protein-nucleic acid interactions.
• Heat-induced disassembly involves the disruption of cooperative intersubunit and protein-nucleic acid interactions.
• The findings provide critical insights into the stability of MS2 VLPs, informing their use in biomedical applications.