Structure and composition of influenza virus. A small-angle neutron scattering study

Area of Science:

• Virology
• Structural Biology
• Biophysics

Background:

• Influenza B virus is a significant human pathogen.
• Understanding the virus's low-resolution structure is crucial for antiviral development.

Purpose of the Study:

• To determine the low-resolution structure of Influenza B virus using small-angle neutron scattering.
• To analyze the contribution of different viral components to the overall structure.

Main Methods:

• Small-angle neutron scattering (SANS) on intact and bromelain-treated Influenza B virus solutions.
• Analysis of scattering curves using spherical shell models and contrast variation.
• Comparison with scanning transmission electron microscopy and cryo-electron microscopy data.

Main Results:

• Influenza B virus particles are spherical, ~1200 A in diameter, with a molecular mass of ~180 x 10^6.
• The lipid bilayer is located at a radius of 425 A and constitutes 25-28% of the virus mass.
• Surface glycoproteins (haemagglutinin) account for 40-46% of the mass, with surprisingly little interior protein.

Conclusions:

• The study provides a detailed low-resolution structural model of Influenza B virus.
• The findings suggest potential variations in internal protein content among virus particles.
• The methods developed are applicable to structural studies of other lipid-bilayer-containing viruses.