O'Harte F, Bockman C S, Zeng W, Abel P W, Harvey S, Conlon J M
Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178.
Peptides. 1991 Jul-Aug;12(4):809-12. doi: 10.1016/0196-9781(91)90138-f.
An extract of chicken intestine contained neuromedin U-like immunoreactivity (36 pmol/g wet tissue weight). The primary structure of the predominant molecular form (NMU-9), comprising 94% of the total immunoreactivity, was established as: Gly-Tyr-Phe-Phe-Phe-Arg-Pro-Arg- Asn-NH2. This sequence differs from that of pig neuromedin U-8 (NMU-8) by the substitution of Leu3 by Phe and, like the corresponding peptide from the guinea pig, is extended from the NH2-terminus by a Gly residue. A minor component of neuromedin U comprised 25 amino acid residues. An extract of chicken whole brain contained much less NMU-like immunoreactivity (1.5 pmol/g) and the nonpeptide was the only molecular form detected. Synthetic chicken NMU-9 produced a concentration-dependent contraction of smooth muscle from the rat uterus and its effect was unchanged in the presence of tetrodotoxin, atropine and indomethacin. The potency of chicken NMU-9 (EC50 360 +/- 60 nM; mean +/- S.E., n = 6) was approximately 8-fold less than that of pig NMU-8 (EC50 46 +/- 8 nM) but the maximum contraction produced by both agonists was not significantly different.
鸡肠提取物中含有神经介素U样免疫反应性物质（36皮摩尔/克湿组织重量）。占总免疫反应性94%的主要分子形式（NMU - 9）的一级结构确定为：甘氨酸 - 酪氨酸 - 苯丙氨酸 - 苯丙氨酸 - 苯丙氨酸 - 精氨酸 - 脯氨酸 - 精氨酸 - 天冬酰胺 - NH2。该序列与猪神经介素U - 8（NMU - 8）的序列不同，在于亮氨酸3被苯丙氨酸取代，并且与豚鼠相应肽一样，在NH2末端由一个甘氨酸残基延伸。神经介素U的次要成分包含25个氨基酸残基。鸡全脑提取物中神经介素U样免疫反应性物质含量少得多（1.5皮摩尔/克），且检测到的唯一分子形式为非肽形式。合成的鸡NMU - 9可引起大鼠子宫平滑肌浓度依赖性收缩，在存在河豚毒素、阿托品和吲哚美辛的情况下其作用不变。鸡NMU - 9的效力（EC50为360±60纳摩尔；平均值±标准误，n = 6）比猪NMU - 8（EC50为46±8纳摩尔）约低8倍，但两种激动剂产生的最大收缩无显著差异。
