[Met⁵]Enkephalin acetate salt hydrate

Tyr-Gly-Gly-Phe-Met

[Met5] Enkephalin (ME) is an opioid pentapeptide, which acts as a neurotransmitter or neuromodulator in the central nervous system. [Met5] Enkephalin is activated on interaction with three main subtypes of receptors including μand δ opioid receptors mediating classic opioid effects of met-Enk and ζ -receptors mediating non-opioid actions of the peptide, i.e. retardation of cell growth. [Met5] Enkephalin is derived from precursor peptide pro-methionine-enkephalin in vitro consisting of H-Tyr-Gly-Gly-Phe-Met-Arg-OH amino acid sequence. The peptide activity is observed in the central nervous, neuroendocrine and immune systems.

[Met5] Enkephalin acetate salt hydrate has been used to study the effect of mutations in opioid growth factor receptor on growth of human cancer cell line.

Met-enkephalin is endogenous opioid neurotransmitter/neuromodulator with agonist activity at μ and δ opioid receptors. Enhancement of immune system function is mediated through met-enkephalin receptors on leukocytes. Met-enkephalin also functions as a growth factor on many cell types at a receptor that is distinct from the neuronal opioid receptors.

Opioid peptides play a crucial role in various physiological process such as pain mediation, opiate dependence and euphoria and members of this class contain aromatic residues in positions 1 and 4. [Met5] Enkephalin acts as a cytokine and is implicated in improving immune response in patients with cancer or AIDS. [Met5] Enkephalin boosts immune functions at low concentration and suppress at high concentration. ME is associated with glucose homeostasis. Increased concentration of ME is observed in plasma of type I diabetic patients.