Shen F S, Lindberg I
Department of Biochemistry and Molecular Biology, LSU Medical Center, New Orleans 70112.
Neuropeptides. 1989 Jan;13(1):17-22. doi: 10.1016/0143-4179(89)90016-4.
A low molecular weight Methionine enkephalin-immunoreactive peptide (MEIP) and two Leucine-enkephalin immunoreactive peptides (LEIP) generated by peptic digestion of rat plasma were purified through gel filtration followed by five sequential reverse phase HPLC gradients in different solvent systems. Binding experiments of these peptides to opioid receptors of rat brains were performed. The two LEIPs were able to inhibit binding of [3H]naloxone to opioid receptors in rat brain membranes. No inhibition was found with the MEIP (which represented the only MEIP present in the low molecular weight fraction of pepsin-digested rat plasma). Sequencing revealed that the MEIP is a six residue peptide with the following sequence: Gly-Glu-Tyr-Gly-Phe-Gln. This sequence corresponds to that of residues 422-427 of rat serum albumin.
一种低分子量的蛋氨酸脑啡肽免疫反应性肽（MEIP）以及通过对大鼠血浆进行胃蛋白酶消化产生的两种亮氨酸脑啡肽免疫反应性肽（LEIP），先经凝胶过滤，然后在不同溶剂系统中进行五次连续的反相高效液相色谱梯度分离后得以纯化。对这些肽与大鼠脑阿片受体的结合实验进行了研究。两种LEIP能够抑制[³H]纳洛酮与大鼠脑膜中阿片受体的结合。而MEIP（它是胃蛋白酶消化的大鼠血浆低分子量部分中唯一存在的MEIP）未发现有抑制作用。测序显示MEIP是一种六肽，其序列如下：甘氨酸 - 谷氨酸 - 酪氨酸 - 甘氨酸 - 苯丙氨酸 - 谷氨酰胺。该序列与大鼠血清白蛋白422 - 427位残基的序列相对应。
