Enkephalins

An enkephalin is a pentapeptide ending with either leucine ("leu") or methionine ("met"). Both are products of the proenkephalin gene.


 * [Met]-enkephalin is Tyr-Gly-Gly-Phe-Met.
 * [Leu]-enkephalin has Tyr-Gly-Gly-Phe-Leu.

Enkephalins play many roles in regulating pain.