O'Harte F, Burcher E, Lovas S, Smith D D, Vaudry H, Conlon J M
Department of Biomedical Sciences, Creighton University Medical School, Omaha, Nebraska 68178.
J Neurochem. 1991 Dec;57(6):2086-91. doi: 10.1111/j.1471-4159.1991.tb06426.x.
An extract of the whole brain of the frog Rana ridibunda contained high concentrations of substance P-like immunoreactivity, measured with an antiserum directed against the COOH-terminal region of mammalian substance P and neurokinin B-like immunoreactivity, measured with an antiserum directed against the NH2-terminus of neurokinin B. The primary structure of the substance P-related peptide (ranakinin) was established as: Lys-Pro-Asn-Pro-Glu-Arg-Phe-Tyr-Gly-Leu-Met-NH2. Mammalian substance P was not present in the extract. The primary structure of the neurokinin B-related peptide was established as: Asp-Met-His-Asp-Phe-Phe-Val-Gly-Leu-Met-NH2. This amino acid sequence is the same as that of mammalian neurokinin B. Ranakinin was equipotent with substance P and [Sar9,Met(O2)11]substance P in inhibiting the binding of 125I-Bolton-Hunter-[Sar9,Met(O2)11]substance P, a selective radioligand for the NK1 receptor, to binding sites in rat submandibular gland membranes (IC50 1.6 +/- 0.3 nM; n = 5). It is concluded that ranakinin is a preferred agonist for the mammalian NK1 tachykinin receptor subtype.
用针对哺乳动物P物质COOH末端区域的抗血清测定，泽蛙全脑提取物中含有高浓度的P物质样免疫反应性；用针对神经激肽B NH2末端的抗血清测定，提取物中含有高浓度的神经激肽B样免疫反应性。P物质相关肽（泽蛙激肽）的一级结构确定为：Lys-Pro-Asn-Pro-Glu-Arg-Phe-Tyr-Gly-Leu-Met-NH2。提取物中不存在哺乳动物P物质。神经激肽B相关肽的一级结构确定为：Asp-Met-His-Asp-Phe-Phe-Val-Gly-Leu-Met-NH2。该氨基酸序列与哺乳动物神经激肽B的序列相同。泽蛙激肽在抑制125I-博尔顿-亨特-[Sar9,Met(O2)11]P物质（一种NK1受体的选择性放射性配体）与大鼠颌下腺膜结合位点的结合方面，与P物质和[Sar9,Met(O2)11]P物质等效（IC50 1.6 +/- 0.3 nM；n = 5）。得出的结论是，泽蛙激肽是哺乳动物NK1速激肽受体亚型的首选激动剂。
