自从1975年发现脑啡肽以来,已分离出许多阿片肽,如β-内啡肽、强啡肽_(1～17)(dynorphinl-17)及E肽(Peptide-E).在这些肽的N端均含有甲硫-脑啡肽或亮-脑啡肽的序列。近来已经知道所有阿片肽源于三种不同的蛋白质前体.垂体内有ACTH及β-内啡肽的共同前体(原-阿片黑色素皮质素——Pro-opiomelanocortin,POMC)。在肾上腺髓质中有甲硫-及亮-脑啡肽的共同前体(脑啡肽原,Pro-enkephalin)。这些前体的详细 Many opioids, such as beta-endorphin, dynorphin 1-17 and Peptide-E, have been isolated since the enkephalin was discovered in 1975. In these peptides Methylthio-enkephalin or leu-enkephalin sequences are contained at the N-terminus. It has recently been known that all opioids derive from three different protein precursors, a common precursor of ACTH and beta-endorphin (Pro-opiomelanocortin, POMC) in the pituitary gland. In the adrenal medulla there is a common precursor of thiol-enkephalin (Pro-enkephalin). The details of these precursors