Pentameric protein

These five chains assemble together (along with certain receptors like protons or acetylcholine) forming the structure of the channel.

They are acetylcholine-operated ion channels, which means that acetylcholine brings about a conformational change.

The channel allows the free movement of the cations like Na+ and K+ when acetylcholine binds to its receptors.

Many viral capsids are formed by hexameric and pentameric proteins.

[3] Synthetic pentameric proteins include MHC pentamers, a type of MHC multimer, comprising five peptide-MHC complexes associated via a coiled-coil domain, attached to five fluorophore moieties.