Leu-Enkephalin

**Semantic type:** Amino Acid, Peptide, or Protein

**Definition:** Leu-enkephalin (5 aa, ~1 kDa) is encoded by the human PENK gene. This protein is involved in the activation of mu and delta opioid receptors.

**Synonyms:** - Tyr-Gly-Gly-Phe-Leu - YGGPL