Zamir N, Palkovits M, Weber E, Mezey E, Brownstein M J
Nature. 1984;307(5952):643-5. doi: 10.1038/307643a0.
The amino acid sequence of the opioid peptide Leu-enkephalin is found within several larger peptides, which are generated from the precursors proenkephalin and prodynorphin. Proenkephalin contains four copies of the sequence of Met-enkephalin, a single copy of the sequence of Leu-enkephalin and one copy each of two extended Met-enkephalin sequences. Proenkephalin contains three peptides--alpha-neo-endorphin, dynorphin A and dynorphin B--the N-terminal sequences of which are identical to that of Leu-enkephalin. There is good evidence that the large amounts of Leu-enkephalin found in the adrenal medulla are generated from the precursor proenkephalin, but as yet prodynorphin has not been shown to be processed to yield Leu-enkephalin. We show here that the relatively high levels of Leu-enkephalin found in the rat substantia nigra are supplied by striatonigral axons and generated from the precursor prodynorphin.
阿片肽亮氨酸脑啡肽的氨基酸序列存在于几种较大的肽中，这些较大的肽由前体脑啡肽原和强啡肽原产生。脑啡肽原包含甲硫氨酸脑啡肽序列的四个拷贝、亮氨酸脑啡肽序列的一个拷贝以及两个延伸的甲硫氨酸脑啡肽序列各一个拷贝。脑啡肽原包含三种肽——α-新内啡肽、强啡肽A和强啡肽B——它们的N端序列与亮氨酸脑啡肽的相同。有充分证据表明，肾上腺髓质中发现的大量亮氨酸脑啡肽是由前体脑啡肽原产生的，但迄今为止，尚未证明强啡肽原可加工产生亮氨酸脑啡肽。我们在此表明，大鼠黑质中发现的相对高水平的亮氨酸脑啡肽由纹状体黑质轴突提供，并由前体强啡肽原产生。
