Genetically Engineered, Multichromophore Virus-Like Nanoparticles with Ultranarrow Distribution of Emission...

Area of Science:

• Biophysics
• Materials Science
• Nanotechnology

Background:

• Variance in optical mesoscopic probes limits applications, with smaller probes exhibiting larger relative variance.
• Viral protein cages can self-assemble with high fidelity, bypassing equilibrium statistical limitations.
• Existing fluorescent nanosphere probes have limitations in brightness and intensity distribution.

Purpose of the Study:

• To leverage the stoichiometric and structural accuracy of viral capsid assembly for creating superior fluorescent probes.
• To demonstrate the potential of engineered viral protein cages as multichromophore particles with enhanced fluorescence properties.

Main Methods:

• Engineered murine polyoma virus coat proteins fused with superfolding green fluorescent protein (sfGFP).
• In vitro self-assembly of virus-like particles (VLPs).
• Charge-detection mass spectrometry for stoichiometric analysis.
• Single-particle total internal reflection fluorescence microscopy for fluorescence intensity characterization.

Main Results:

• Self-assembled VLPs from sfGFP-murine polyoma virus coat proteins exhibited stoichiometry comparable to wild-type VLPs.
• Demonstrated bright fluorescence intensity from multichromophore particles.
• Observed a narrow distribution of fluorescence intensity, indicative of stoichiometric accuracy.

Conclusions:

• Engineered viral protein cages can produce highly uniform and bright fluorescent nanoparticles.
• This approach surpasses the performance of current state-of-the-art fluorescent nanosphere probes.
• The precise self-assembly mechanism of viral capsids offers a powerful strategy for developing advanced optical probes.