Analysis of the adrenal angiotensin II receptor with the photoaffinity labeling method.-猫眼课题宝

用光亲和标记法分析肾上腺血管紧张素 II 受体。

DOI：

发表时间：

1983

期刊：

Biochemistry

影响因子：

2.9

通讯作者：

中科院分区：

生物学3区

文献类型：

作者：

G. Guillemette;E. Escher

牛肾上腺皮质的血管紧张素II （Asp-Arg-Val-Tyr-Ile-His-Pro-Phe， AT）受体已经用AT光敏类似物进行了研究。在第一个系列的实验中，我们已经证明，如果分离的皮质细胞在光标记物[Sar1，（4′-N3）Phe8]AT的存在下被光解，它们会以永久和特异性的方式分泌醛固酮。这种永久性刺激与平滑肌试验相反，在类似条件下，总是观察到永久性和特异性阻滞。据推测，AT受体的不可逆占据产生了这种效应。在第二种类型的实验中，我们已经证明，在类似的条件下，肾上腺皮质膜上的AT结合位点可以被特异性和不可逆地占据，并且这种占据可以通过非光敏激素的存在以竞争性的方式阻止。使用放射性标记物[Sar1，（3'-125I）Tyr4,(4'-N3)Phe8]AT，我们在非还原和非变性条件下通过凝胶过滤鉴定出AT受体为300 kda蛋白。在还原和变性条件下，通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和凝胶过滤，发现了一个60 kDs的亚基。AT受体被认为是一个300 kDa的蛋白，具有一个60 kDa的结合亚基。

The angiotensin II (Asp-Arg-Val-Tyr-Ile-His-Pro-Phe, AT) receptor of bovine adrenocortex has been investigated with photosensitive analogues of AT. In a first series of experiments, we have shown that isolated cortical cells secrete aldosterone in a permanent and specific manner if they have been photolyzed in the presence of the photolabel [Sar1,(4'-N3)Phe8]AT. This permanent stimulation is in contrast to the smooth muscle assays where under similar conditions a permanent and specific block was always observed. It is assumed that the irreversible occupation of the AT receptor produces this effect. In a second type of experiment, we have shown that the AT binding site on adrenocortical membranes can be specifically and irreversibly occupied under similar conditions and that this occupation can be prevented in a competitive manner by the presence of nonphotosensitive hormone. Using a radioactive label, [Sar1,(3'-125I)Tyr4,(4'-N3)Phe8]AT, we have identified the AT receptor as a 300-kDa protein by means of gel filtration under nonreducing and nondenaturating conditions. Under reducing and denaturing conditions, a subunit of 60 kDs was found by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration. The AT receptor is proposed to be a 300-kDa protein with one binding subunit of 60 kDa.

Covalent crosslinking of angiotensin II to its binding sites in rat adrenal membranes.