Human testicular androgen-binding protein shares immunodeterminants with serum testosterone-estradiol-binding globulin.
Human testicular androgen-binding protein shares immunodeterminants with serum testosterone-estradiol-binding globulin.
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人睾丸雄激素结合蛋白与血清睾酮雌二醇结合球蛋白共享免疫决定簇。
DOI：
10.1210/endo-114-4-1395
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发表时间：
1984
期刊：
影响因子：
4.8
通讯作者：
C. W. Bardin
中科院分区：
文献类型：
--
作者：
C. Cheng;Julian Frick;G. Gunsalus;N. Musto;C. W. Bardin
在人类中，有两种糖蛋白，睾酮-雌二醇结合球蛋白（hTeBG）和雄激素结合蛋白（hABP），其结合睾酮。虽然这两种蛋白质具有相似的物理化学性质，但它们可以根据来源和凝集素结合来区分。hTeBG在肝脏中产生，并对伴刀豆球蛋白A（Con A）表现出高亲和力，而来自睾丸的hABP仅部分结合于该凝集素。也就是说，当睾丸提取物应用于Con A-琼脂糖凝胶柱时，一部分睾酮结合材料显示与凝集素没有相互作用并在空隙体积中洗脱（峰I），而其余部分强烈相互作用并可与α-甲基-D-葡萄糖苷洗脱（峰II）。这些观察结果与峰I仅含有hABP，而峰II含有hTeBG和/或具有允许与Con A结合的碳水化合物单元的hABP的提议一致。为了进一步研究这些结合蛋白的性质，使用单特异性抗血清的hTeBG RIA来比较睾丸和血清中的蛋白。结果表明，睾丸提取物峰I和峰II中的睾酮结合活性无法从免疫学上与正常女性血清中的hTeBG区分开来。这些发现表明hTeBG和hABP具有共同的表位。我们接下来通过在Con A-Sepharose柱中分离这些液体来确定hABP是否分泌到血液或羊水中。与睾丸提取物不同，男性血清和羊水含有单一的免疫反应性和类固醇结合物质，其特异性结合Con A。我们从这些观察中得出结论，hABP（峰I），峰II活性和hTeBG具有共同的免疫决定簇，如果hABP分泌到男性血液中，则其碳水化合物链与Con A结合，使其在这些条件下与hTeBG无法区分。
In the human, there are two glycoproteins, testosterone-estradiol-binding globulin (hTeBG) and androgen-binding protein (hABP), which bind testosterone. Although these two proteins have similar physicochemical properties, they can be distinguished on the basis of origin and lectin binding. hTeBG is made in the liver and exhibits high affinity for Concanavalin A (Con A), while hABP from the testes is only partially bound to this lectin. That is, when testicular extracts were applied to Con A-Sepharose columns, a portion of the testosterone-binding material showed no interaction with the lectin and eluted in the void volume (peak I), while the remainder interacted strongly and could be eluted with alpha-methyl-D-glucoside (peak II). These observations are consistent with the proposal that peak I contains only hABP, whereas peak II contains hTeBG and/or hABP with carbohydrate units that permit binding to Con A. To further study the properties of these binding proteins, a hTeBG RIA using a monospecific antiserum was employed to compare the proteins in testes and serum. The results indicated that the testosterone-binding activities in peaks I and II of testicular extracts could not be distinguished immunologically from hTeBG in sera of normal women. These findings suggested that hTeBG and hABP share common epitopes. We next determined whether hABP was secreted into the blood or amniotic fluid by fractionating these fluids in Con A-Sepharose columns. Unlike testicular extracts, male serum and amniotic fluid contained single immunoreactive and steroid-binding species which bound specifically to Con A. We conclude from these observations that hABP (peak I), peak II activity, and hTeBG have common immunodeterminants and that if hABP is secreted into the blood of men, then its carbohydrate chains bind to Con A, making it indistinguishable from hTeBG under these conditions.