Enkephalins

Pentapeptides are formed from ß-lipotropin (91 a. a.), which is formed from proopiomelanocortin. Pentapeptides are found in the brain, spinal cord cerebrospinal fluid, and intestines. Met (methionine) enkephalins have a Tyr-Gly-Gly-Phe-Met structure. Leu (leucine) enkephalins have a Tyr-Gly-Gly-Phe-Leu sequence. These two sequences are also found in many opioid peptides at the N-terminus. However, the physiological source of enkephalins is preproenkephalin A, a protein with 267 amino acid residues. Its sequence has been identified from cloned DNA. It exhibits opioid activity similar to morphine, which reduces pain.

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė