Several families of endogenous opioid peptides, the endorphins, enkephalins and dynorphins, have been identified in the mammalian central nervous system. The peptides of these families contain an N-terminal Tyr-Gly-Gly-Phe- sequence but are derived from different precursor proteins: proopiomelanocortin (POMC), proenkephalin (PENK) and prodynorphin (PDYN). Proteolytic processing of POMC results in the generation of ß-endorphin. Processing of PENK yields Met-enkephalin and Leu-enkephalin. Dynorphin A and B are derived from PDYN.

An additional family of endogenous opioid peptides is represented by the endomorphins. This family consists of endomorphin-1 (H-Tyr-Pro-Trp-Phe-NH2) and -2 (H-Tyr-Pro-Phe-Phe-NH2).

Endogenous opioid peptides can be produced by neuronal and non-neuronal tissue. They act via opioid receptors (mu, kappa, delta). ß-endorphin preferentially signals through mu and delta receptor subtypes, endomorphins through mu, Met- and Leu-enkephalin through delta receptors. Dynorphin A and B show selectivity for the kappa receptors.


  • Dynorphin, analogs and sequences
  • Endomorphins
  • Endorphins, analogs and fragments
  • Enkephalins and proenkephalins

Bachem also offers a wide range of immunology products.

Immunology products

  • Dynorphins and fragments
  • Endomorphins
  • Endorphins
  • Enkephalins

Many of our opioid peptides are also offered as tracers.

  • 125I-labelled peptides

For additional information on these and many other biologically active peptides and immunology products please visit our website.