O'Harte F, Bockman C S, Abel P W, Conlon J M
Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178.
Peptides. 1991 Jan-Feb;12(1):11-5. doi: 10.1016/0196-9781(91)90159-m.
The neuromedin U-like immunoreactivity in an extract of dog small intestine was resolved by reversed-phase HPLC into two molecular forms. The primary structure of the larger form (NMU-25) was established as: Phe-Arg-Leu-Asp-Glu-Glu-Phe-Gln-Gly-Pro10-Ile-Ala-Ser-Gln-Val-Arg- Arg-Gln-Phe- Leu20-Phe-Arg-Pro-Arg-Asn-NH2. This sequence shows five substitutions relative to pig neuromedin U-25. The primary structure of the second peptide (NMU-8) was established as: pGlu-Phe-Leu-Phe-Arg-Pro-Arg-Asn-NH2. The sequence contains the substitution pGlu for Tyr1 compared with pig neuromedin U-8. The potency of synthetic dog NMU-8 in contracting smooth muscle from the rat uterus (EC50 10 +/- 2 nM; mean +/- S.E., n = 6) was not significantly different from the corresponding potency of pig NMU-8 (EC50 16 +/- 5 nM) but the maximum response produced by the dog peptide was greater (58%; p less than 0.05) than that produced by pig NMU-8.
犬小肠提取物中的神经介素U样免疫反应性通过反相高效液相色谱法被分离为两种分子形式。较大形式（NMU-25）的一级结构确定为：苯丙氨酸-精氨酸-亮氨酸-天冬氨酸-谷氨酸-谷氨酸-苯丙氨酸-谷氨酰胺-甘氨酸-脯氨酸10-异亮氨酸-丙氨酸-丝氨酸-谷氨酰胺-缬氨酸-精氨酸-精氨酸-谷氨酰胺-苯丙氨酸-亮氨酸20-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-25相比有五个取代。第二种肽（NMU-8）的一级结构确定为：焦谷氨酸-苯丙氨酸-亮氨酸-苯丙氨酸-精氨酸-脯氨酸-精氨酸-天冬酰胺-NH2。与猪神经介素U-8相比，该序列在第1位含有用焦谷氨酸取代酪氨酸的情况。合成的犬NMU-8对大鼠子宫平滑肌收缩的效力（EC50为10±2 nM；平均值±标准误，n = 6）与猪NMU-8的相应效力（EC50为16±5 nM）无显著差异，但犬肽产生的最大反应比猪NMU-8产生的最大反应大（58%；p＜0.05）。
