Relationships of thyrotropin to exophthalmic-producing substance. Purification of homogeneous glycoproteins containing both activities from [3H]-labeled pituitary extracts.
Relationships of thyrotropin to exophthalmic-producing substance. Purification of homogeneous glycoproteins containing both activities from [3H]-labeled pituitary extracts.
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促甲状腺素与突眼物质的关系。
DOI：
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发表时间：
1970
影响因子：
4.8
通讯作者：
L. Kohn
中科院分区：
文献类型：
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作者：
R. Winand;L. Kohn
摘要 通过柱色谱标准程序纯化的促甲状腺素制剂含有几种电泳上不同的成分，这些成分具有致眼活性并含有半乳糖。尽管制备型圆盘凝胶电泳可以将这些异质制剂解析成单独的糖蛋白，但所得的一些成分仍然具有促甲状腺和突眼活性。两种这样的糖蛋白，每种都具有两种活性，在超速离心机中是均质的，分子量为 27,000 ± 3,000。它们具有相似（即使不相同）的氨基酸组成。这些数据强化了先前的建议，即促甲状腺活性和促眼球活性的决定因素可能位于同一糖蛋白分子上。糖蛋白的末端半乳糖残基可以用氚酶标记。该过程包括将糖蛋白初步暴露于半乳糖氧化酶，随后用(3H)硼氢化钠还原。该技术的应用已经确定了通过制备型凝胶电泳获得的多活性但均质制剂中半乳糖的末端性质。氚化糖蛋白中保留了促甲状腺活性和促眼球活性。该程序适用于粗垂体制剂，一旦去除了几种污染物糖蛋白，氚就可以作为单个促甲状腺和突眼物种的方便标记。来自小鼠可移植肿瘤的促甲状腺激素还含有可以通过氚化标记的末端半乳糖。与牛促甲状腺素的明显差异还体现在其糖成分上。
Abstract Preparations of thyrotropin which are purified by standard procedures of column chromatography contain several electrophoretically distinct components which have exophthalmogenic activity and contain galactose. Although preparative disc gel electrophoresis can resolve these heterogeneous preparations into individual glycoproteins, several of the resultant components still have both thyrotropic and exophthalmogenic activity. Two such glycoproteins, each with both activities, are homogeneous in the ultracentrifuge, with a molecular weight of 27,000 ± 3,000. They have a similar, if not identical, amino acid composition. Previous suggestions that the determinants for both thyrotropic and exophthalmogenic activity can reside on the same glycoprotein molecule are reinforced by these data. Terminal galactose residues of glycoproteins may be enzymatically labeled with tritium. This procedure involves a preliminary exposure of the glycoprotein to galactose oxidase and subsequent reduction with (3H) sodium borohydride. Application of this technique has established the terminal nature of galactose in the multiactive but homogeneous preparations obtained by preparative gel electrophoresis. Both the thyrotropic and the exophthalmogenic activities are preserved in the tritiated glycoproteins. The procedure is applicable to crude pituitary preparations, the tritium serving as a convenient marker of the individual thyrotropic and exophthalmogenic species once the several contaminant glycoproteins have been removed. Thyroid-stimulating hormone derived from mouse transplantable tumors also contains terminal galactose which can be labeled by tritiation. Distinct differences from bovine thyrotropin can otherwise be shown in its sugar composition.