Paterson S J, Corbett A D, Gillan M G, Kosterlitz H W, McKnight A T, Robson L E
J Recept Res. 1984;4(1-6):143-54. doi: 10.3109/10799898409042545.
The three endogenous opioid precursors of almost 30000 Da are pro-opiocortin, proenkephalin and prodynorphin. Pro-opiocortin contains beta-endorphin, melanotropins and ACTH. Proenkephalin yields one [Leu5]enkephalin, three [Met5]enkephalins, one [Met5] enkephalyl-Arg-Arg-Val-NH2 (metorphamide or adrenorphin), one [Met5]enkephalyl-Arg-Gly-Leu and one [Met5]enkephalyl-Arg-Phe. [Leu5]enkephalin is common to all fragments of prodynorphin; its carboxyl extension by Arg-Lys leads to alpha- and beta-neo-endorphin and its carboxyl extension by Arg-Arg gives two dynorphins A and B of 17 and 13 amino acids, respectively. Another endogenous peptide is dynorphin A (1-8). The three main opioid binding sites are mu, delta and kappa. Their analysis has been facilitated by the synthesis of analogues of peptides and non-peptide compounds, which have selective agonist or antagonist action at only one site. The various physiological roles of the three types of the opiate receptor have so far not been sufficiently investigated.
分子量近30000道尔顿的三种内源性阿片肽前体分别是阿片皮质素原、脑啡肽原和强啡肽原。阿片皮质素原包含β-内啡肽、促黑素细胞激素和促肾上腺皮质激素。脑啡肽原产生一种亮氨酸脑啡肽、三种甲硫氨酸脑啡肽、一种甲硫氨酸脑啡肽-精氨酸-精氨酸-缬氨酸-氨基（甲硫啡肽或肾上腺啡肽）、一种甲硫氨酸脑啡肽-精氨酸-甘氨酸-亮氨酸和一种甲硫氨酸脑啡肽-精氨酸-苯丙氨酸。亮氨酸脑啡肽存在于强啡肽原的所有片段中；其羧基端通过精氨酸-赖氨酸延伸可形成α-和β-新内啡肽，通过精氨酸-精氨酸延伸则分别产生由17个和13个氨基酸组成的两种强啡肽A和B。另一种内源性肽是强啡肽A（1-8）。三种主要的阿片肽结合位点分别是μ、δ和κ。肽类和非肽类化合物类似物的合成有助于对它们的分析，这些类似物仅在一个位点具有选择性激动剂或拮抗剂作用。迄今为止，三种类型阿片受体的各种生理作用尚未得到充分研究。
