BIOPHYSICAL PROPERTIES OF PREPARATIONS OF PR8 INFLUENZA VIRUS

Area of Science:

• Virology
• Biophysics

Background:

• Understanding the physical characteristics of influenza viruses is crucial for virology and developing antiviral strategies.
• Previous studies have provided limited data on the biophysical properties of PR8 influenza virus preparations.

Purpose of the Study:

• To comprehensively investigate the biophysical properties of PR8 influenza virus.
• To elucidate the reasons behind discrepancies in particle size measurements and sedimentation behavior.

Main Methods:

• Electron microscopy for particle size and morphology.
• Pycnometry for specific volume determination.
• Ultracentrifugation in varying sucrose densities to assess sedimentation rates and density.
• Viscometry to determine intrinsic viscosities.

Main Results:

• Electron microscopy indicated irregular, circular PR8 influenza virus particles with an average diameter of 115 µm.
• Sedimentation rate varied inversely with virus concentration, with extrapolated values of 722 and 658 Svedberg units.
• Hydration of approximately 60% by weight was inferred, leading to an estimated hydrated particle diameter of 100 µm, reconciling electron microscopy and sedimentation data.

Conclusions:

• PR8 influenza virus particles are significantly hydrated, influencing their observed physical properties.
• The hydration model explains variations in particle size, sedimentation rates, and density measurements.
• Accurate characterization of influenza virus biophysics is essential for understanding its behavior and developing effective interventions.