Rondeau J J, McNicoll N, Escher E, Meloche S, Ong H, De Léan A
Clinical Research Institute of Montreal, Quebec, Canada.
Biochem J. 1990 Jun 1;268(2):443-8. doi: 10.1042/bj2680443.
The bovine adrenal angiotensin II receptor was solubilized with the non-ionic detergent octyl beta-D-glucoside following its binding with the high-affinity antagonist 125I-labelled [Sar1,Ile8]angiotensin II. The complex was sufficiently stable to allow the determination of its hydrodynamic properties. The solubilized receptor migrated on a Superose 6 column as a single peak with a Stokes radius of 5.29 nm. Comparison of sedimentation behaviour through a sucrose density gradient in H2O and 2H2O lead to a partial specific volume of 0.751 ml/g and a sedimentation coefficient (S20,w) of 5.17 S. Combination of gel filtration and sedimentation data indicated that the labelled protein-detergent complex has an Mr of 124,000 and a frictional ratio of 1.42. The Mr of the angiotensin II receptor was estimated as 104,000 kDa after correction for the bound detergent. Photoaffinity cross-linking of 125I-[Sar1, (4-N3)Phe8]angiotension II with bovine adrenal membrane receptor followed by SDS/PAGE under reducing and non-reducing conditions yielded a broad band of Mr 54,000. This suggests that the angiotensin II receptor is a non-covalent dimer in which the two subunits have a similar Mr.
牛肾上腺血管紧张素II受体与高亲和力拮抗剂125I标记的[Sar1，Ile8]血管紧张素II结合后，用非离子去污剂辛基β-D-葡萄糖苷进行增溶。该复合物足够稳定，可用于测定其流体力学性质。增溶后的受体在Superose 6柱上以单峰形式迁移，斯托克斯半径为5.29 nm。通过在H2O和2H2O中的蔗糖密度梯度比较沉降行为，得出其偏比容为0.751 ml/g，沉降系数（S20,w）为5.17 S。凝胶过滤和沉降数据相结合表明，标记的蛋白质-去污剂复合物的Mr为124,000，摩擦比为1.42。校正结合的去污剂后，血管紧张素II受体的Mr估计为104,000 kDa。125I-[Sar1，(4-N3)Phe8]血管紧张素II与牛肾上腺膜受体进行光亲和交联，然后在还原和非还原条件下进行SDS/PAGE，得到一条Mr为54,000的宽带。这表明血管紧张素II受体是一种非共价二聚体，其中两个亚基的Mr相似。
