Understanding Capsid Proteins and Virus Entry

Capsid Proteins and Receptor Binding Mechanisms

Capsid proteins form the outer shell of a virus.
They protect the viral genome.
They also control host cell entry.

Most viral capsids are made of repeating protein units.
These units assemble with high precision.
Structure determines function.

Receptor binding is the first step of infection.
Capsid proteins recognize specific host receptors.
This interaction defines host range.

Binding occurs through surface loops and pockets.
Small structural changes can alter affinity.
Mutations may increase infectivity.

In enteroviruses, VP1 plays a key role.
It contains the main receptor-binding site.
VP2 and VP3 provide structural support.

Some receptors are proteins.
Others are carbohydrates or lipids.
Each virus has a preferred target.

After binding, conformational changes occur.
The capsid becomes unstable.
This allows genome release.

Receptor engagement can trigger endocytosis.
The virus enters through cellular vesicles.
Uncoating follows soon after.

Understanding these mechanisms aids drug design.
Capsid inhibitors block receptor interaction.
Vaccines target exposed capsid regions.

Capsid–receptor studies guide antiviral strategies.
They reveal viral evolution patterns.
They support disease prevention efforts.