Α-Endorphin
α-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.
Relation to beta- and gamma-endorphin
Endorphins are generally known as neurotransmitters that are released when the body goes into pain. The three endorphins that play a role in this response are α-endorphin, β-endorphin, and γ-endorphin which are all derived from the same polypeptide known as pro-opiomelanocortin. Although all play roles as neurotransmitters, the specific effects of all three differ. The most studied endorphin of the three is β-endorphin. α-Endorphins are known to contain one less amino acid than γ-endorphins, differing by a single leucine amino acid at the terminal end. Although this may seem minor, It allows them to have vastly different effects. Studies found that γ-endorphins and α-endorphins have opposite effects which allow them to help maintain a level of homeostasis within the brain and behavior of animals. All of the specific effects on the body of α-endorphins are not yet fully studied nor fully understood by the science community. However, some studies suggest that these endorphins behave similarly to amphetamines. Similarly, other studies agree that Alpha-endorphins effects are similar to psychostimulant drugs.Ranking based length, α-endorphins are the shortest with 16 amino acid residues. Meanwhile, the β-endorphin has the longest chain which begins with the same 16 amino acids as α-Endorphins: Tyr-Gly-Gly-Phe-Met-Thr-Ser-Glu-Lys-Ser-Gln-Thr-Pro-Leu-Val-Thr. The same sequence is also present in γ-endorphin. The beginning Tyr-Gly-Gly-Phe-Met chain is also known as the N-terminal pentapeptide opioid sequence. With such configuration, endorphins act as agonists to opioid receptors in the brain.