Nordmann J J, Schmid D W, Chauveau J, Legros J J
J Biol Chem. 1984 Nov 10;259(21):13111-6.
Neurosecretory granules from bovine neurohypophyses were isolated on iso-osmotic gradients. The content of the granules was analyzed by analytical and two-dimensional gel electrophoreses. The distributions in the gels of vasopressin precursor and neurophysins were detected by radioimmunoassays. Analytical gel electrophoresis of the content of a crude granule preparation showed the presence of different populations of neurophysin molecules. Further analysis demonstrated that vasopressin-neurophysin and oxytocin-neurophysin can be subdivided into molecules with different pI values. Whereas newly formed granules showed two main spots of neurophysin with pI of 5.0 and 5.6, aged granules contain in addition to these different populations of neurophysin-like material, some of which had a basic pI. Vasopressin precursor activity was detected in spots containing proteins with acidic pI and Mr approximately 18,000 and also in proteins of Mr = 8,000-10,000 migrating in the basic region of the gel. The results suggest that in the neural lobe there is an aging process which gives rise to several subpopulations of neurophysins. The different forms of vasopressin-associated bovine neurophysin and oxytocin-associated bovine neurophysin are only found in the granules which are not required for release.
从牛神经垂体中分离出神经分泌颗粒，并在等渗梯度上进行分离。通过分析性凝胶电泳和二维凝胶电泳对颗粒内容物进行分析。通过放射免疫测定法检测血管加压素前体和神经垂体素在凝胶中的分布。粗颗粒制剂内容物的分析性凝胶电泳显示存在不同群体的神经垂体素分子。进一步分析表明，血管加压素 - 神经垂体素和催产素 - 神经垂体素可细分为具有不同pI值的分子。新形成的颗粒显示出两个主要的神经垂体素斑点，pI分别为5.0和5.6，而老化的颗粒除了这些不同群体的神经垂体素样物质外，还含有一些具有碱性pI的物质。在含有酸性pI和Mr约为18,000的蛋白质的斑点中以及在凝胶碱性区域迁移的Mr = 8,000 - 10,000的蛋白质中检测到血管加压素前体活性。结果表明，在神经叶中存在一个老化过程，该过程产生了几个神经垂体素亚群。不同形式的与血管加压素相关的牛神经垂体素和与催产素相关的牛神经垂体素仅在不需要释放的颗粒中发现。
