Russell J T, Brownstein M J, Gainer H
Endocrinology. 1980 Dec;107(6):1880-91. doi: 10.1210/endo-107-6-1880.
[35S]Cysteine-labeled putative precursors for vasopressin-associated neurophysin (NP-VP) and oxytocin-associated neurophysin (NP-OT) were isolated from the supraoptic nuclei (SONs) of normal rats. Homozygous Brattleboro rats were deficient in one of these precursors, the NP-VP precursor. Direct support for the hypothesis that OT and its NP- and VP and its NP are synthesized from two separate macromolecular common precursors was obtained by limited proteolysis of the precursors with trypsin and identification of the fragments as NPs, VP, or OT by a number of criteria (14). In this paper, these common precursors designated propressophysin (precursor for NP-VP and arginine VP) and prooxyphysin (precursor for NP-OT and OT) were further characterized. Propressophysin was specifically bound by Concanavalin-A-Sepharose and was eluted by 0.2 M alpha-methyl mannoside, showing that it is glycosylated. In contrast, prooxyphysin does not appear to be glycosylated. Using [3H]fucose as label injected near the SONs, two proteins (mol wt, approximately 10,000) were identified, which appear to be derived from propressophysin, that are rapidly transported to the posterior pituitary of normal rats. These two proteins were absent in homozygous Brattleboro animals. Both propressophysin and prooxyphysin were bound by a NP-Sepharose affinity support. The binding was different from that of arginine VP or OT to NP, since it was independent of pH and was hydrophobic in nature. In addition to prooxyphysin, the SONs of homozygous Brattleboro rats also contained other [35S]cysteine-labeled protein (mol wt, 20,000) composed of a NP-like protein and NP-binding peptides. The tryptic peptides derived from these proteins were very different in their chromatographic (high performance liquid chromatography) properties than the tryptic peptides derived from propressophysin and prooxyphysin. This protein ('X') was not bound by a Concanavalin-A-Sepharose affinity column, although it had chromatographic properties similar to propressophysin on Sephadex G-75.
从正常大鼠的视上核（SONs）中分离出了用[35S]半胱氨酸标记的血管加压素相关神经垂体素（NP-VP）和催产素相关神经垂体素（NP-OT）的假定前体。纯合布拉特洛维大鼠缺乏这些前体之一，即NP-VP前体。通过用胰蛋白酶对前体进行有限的蛋白水解，并根据多种标准将片段鉴定为神经垂体素、血管加压素或催产素，从而直接支持了催产素及其神经垂体素以及血管加压素及其神经垂体素是由两种不同的大分子共同前体合成的假说（14）。在本文中，这些共同前体被命名为加压素原（NP-VP和精氨酸血管加压素的前体）和催产素原（NP-OT和催产素的前体），并对其进行了进一步的表征。加压素原能与伴刀豆球蛋白A-琼脂糖特异性结合，并能用0.2Mα-甲基甘露糖苷洗脱，表明它是糖基化的。相比之下，催产素原似乎没有糖基化。在视上核附近注射[3H]岩藻糖作为标记物，鉴定出两种蛋白质（分子量约为10,000），它们似乎源自加压素原，并能迅速转运到正常大鼠的垂体后叶。在纯合布拉特洛维动物中不存在这两种蛋白质。加压素原和催产素原都能与神经垂体素-琼脂糖亲和支持物结合。这种结合与精氨酸血管加压素或催产素与神经垂体素的结合不同，因为它不依赖于pH，并且本质上是疏水的。除了催产素原外，纯合布拉特洛维大鼠的视上核还含有其他用[35S]半胱氨酸标记 的蛋白质（分子量为20,000），它由一种类似神经垂体素的蛋白质和神经垂体素结合肽组成。这些蛋白质衍生的胰蛋白酶肽在色谱（高效液相色谱）性质上与加压素原和催产素原衍生的胰蛋白酶肽有很大不同。这种蛋白质（“X”）不能与伴刀豆球蛋白A-琼脂糖亲和柱结合，尽管它在葡聚糖G-75上的色谱性质与加压素原相似。
