Influence of Amino Acid Substitutions in Capsid Proteins of Coxsackievirus B5 on Free Chlorine and Thermal...

Area of Science:

• Virology
• Molecular Biology
• Biochemistry

Background:

• Enterovirus disinfectant sensitivity varies among strains.
• Amino acid changes in capsid proteins are linked to altered resistance.
• The specific impact of individual substitutions remains unclear.

Purpose of the Study:

• To investigate the effect of amino acid substitutions in coxsackievirus B5 (CVB5) capsid proteins on sensitivity to free chlorine and heat.
• To elucidate the role of specific capsid protein alterations in viral stability and disinfection resistance.

Main Methods:

• Reverse genetics was used to introduce specific amino acid substitutions in CVB5 capsid proteins.
• Sensitivity to free chlorine and heat treatment was assessed.
• Cryo-electron microscopy was employed to analyze viral particle assembly and structure.

Main Results:

• Ten amino acid changes in CVB5 variants with free chlorine resistance did not significantly alter chlorine sensitivity.
• A subset of amino acid changes in the C-terminal region of viral protein 1 reduced heat sensitivity.
• These substitutions affected the assembly of intermediate viral states (altered and empty particles).

Conclusions:

• Capsid composition plays a minor role in CVB5 chlorine sensitivity.
• Reduced heat sensitivity is linked to specific amino acid substitutions in viral protein 1.
• Improved molecular packing and altered uncoating dynamics may explain enhanced heat stability in CVB5.