Characterization of the insulin and somatomedin-C receptors in human placental cell membranes.
Characterization of the insulin and somatomedin-C receptors in human placental cell membranes.
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人胎盘细胞膜中胰岛素和生长调节素-C 受体的表征。
DOI：
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发表时间：
1974
影响因子：
5.8
通讯作者：
J. J. Wyk
中科院分区：
文献类型：
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作者：
R. Marshall;L. Underwood;S. Voina;DORETHA B. Foushee;J. J. Wyk
人胎盘被用来进一步研究胰岛素和生长激素与细胞膜受体的结合。确定了125i -胰岛素在参与膜制剂和Triton X-100溶解膜中的最佳结合条件。人胎盘膜是高亲和胰岛素受体的丰富来源。与先前对大鼠肝脏和脂肪细胞制剂的研究一样，只有生长抑素和胰岛素原是与胰岛素受体结合的有效竞争者。这些发现用于确定胰岛素和胰岛素样肽竞争性结合测定的最佳条件。该方法对胰岛素的阈值灵敏度为10 μU/ml，对生长激素的阈值灵敏度小于0.1 μU/ml。在4℃下孵育15-18小时，基本上消除了标记激素的蛋白水解降解，并导致比在更高温度下观察到的更好的结合。一种用放射性碘标记的高纯度生长抑素c制剂被发现…
ABSTRACT Human placentas have been used to further investigate the binding of insulin and somatomedin to cell membrane receptors. Conditions for optimal binding of 125I-insulin were defined for both participate membrane preparations and membranes solubilized in Triton X-100. Human placental membranes are a rich source of high affinity insulin receptors. As in previous studies with rat liver and fat cell preparations, only somatomedin and proinsulin were effective competitors for binding to the insulin receptor. These findings were used to define the optimal conditions for a competitive binding assay for insulin and insulin-like peptides. This assay had threshold sensitivities of 10 μU/ml for insulin and less than 0.1 U/ml for somatomedin. Incubation at 4 C for 15–18 hr essentially eliminated proteolytic degradation of the labeled hormone and led to strikingly better binding than was observed at higher temperatures. A highly purified preparation of somatomedin-C labeled with radioactive iodine was found to...