Dictus W J, Ebberink R H
Department of Biology, Vrije Univesiteit, Amsterdam, The Netherlands.
Mol Cell Endocrinol. 1988 Nov;60(1):23-9. doi: 10.1016/0303-7207(88)90116-5.
The neurosecretory caudo-dorsal of the freshwater pulmonate snail Lymnaea stagnalis, a peptidergic system controlling egg laying and egg-laying behavior, produce several neuropeptides. One of these peptides, calfluxin, causes the influx of Ca2+ into the albumen gland, a female sex gland of the snail. In the present study calfluxin was purified and the amino acid composition was determined. The ratio of the amino acids appeared to be very close to that of one of the predicted peptides present on the egg-laying hormone precursor of Lymnaea. This peptide was synthesized and shows a clear biological activity in the bioassay. Furthermore, it shows a chromatographic behavior similar to that of the natural peptide. Based on these evidences it is concluded that the sequence of calfluxin is: Arg-Val-Asp-Ser-Ala-Asp-Glu-Ser-Asn-Asp-Asp-Gly-Phe-Asp. Calfluxin shows a remarkable homology with the sequence of one of the predicted peptides on the egg-laying hormone precursor of the marine opisthobranch Aplysia californica.
淡水肺螺蛞蝓的神经分泌尾背侧部是一个控制产卵及产卵行为的肽能系统，它能产生多种神经肽。其中一种肽，即钙流蛋白，可使钙离子流入蜗牛的雌性性腺——蛋白腺。在本研究中，钙流蛋白被纯化并测定了氨基酸组成。氨基酸比例似乎与蛞蝓产卵激素前体上预测的一种肽非常接近。该肽被合成出来，并在生物测定中显示出明显的生物活性。此外，它的色谱行为与天然肽相似。基于这些证据，得出结论：钙流蛋白的序列为：精氨酸 - 缬氨酸 - 天冬氨酸 - 丝氨酸 - 丙氨酸 - 天冬氨酸 - 谷氨酸 - 丝氨酸 - 天冬酰胺 - 天冬氨酸 - 天冬氨酸 - 甘氨酸 - 苯丙氨酸 - 天冬氨酸。钙流蛋白与海产后鳃亚纲动物加州海兔产卵激素前体上预测的一种肽的序列具有显著同源性。
