Hexadecapeptides

α-Endorphin (alpha-endorphin) is an endogenous opioid peptide with a length of 16 amino acids, and the amino acid sequence: Tyr-Gly-Gly-Phe-Met-Thr-Ser-Glu-Lys-Ser-Gln-Thr-Pro-Leu-Val-Thr. Researchers at the Salk Institute were pioneers in isolating, sequencing, and synthesizing the peptides they named α- and γ-endorphin, and they determined that they had morphinomimetic activity. With the use of mass spectrometry and dansyl-Edman methods, Nicholas Ling, one of the researchers from the Salk Institute, was able to determine the primary sequence of α-endorphin.