P0 is a major structural component of the myelin sheath in the peripheral nervous system (PNS).

[8] Myelin protein zero consists of an extracellular N-terminal domain (amino acids 1–124), a single transmembrane region (125–150), and a smaller positively charged intracellular region (151–219).

[6][9][10] Its cytoplasmic domain is highly positively charged but presumably does not fold into a globular structure.

[13]The myelin sheath is a multi-layered membrane, unique to the nervous system, that functions as an insulator to greatly increase the velocity of axonal impulse conduction.

[15] Currently, myelin protein zero expression is postulated to be produced by signals from the axon.

[11] It does so by holding its characteristic coil structure together by the electrostatic interactions[8] of its positively charged intracellular domain with acidic lipids in the cytoplasmic face of the opposite bilayer.

[7] Adding a charged amino acid or changing a cysteine residue in the extracellular membrane can lead to neuropathy onset early on.