Zidovetzki R, Johnson D A, Arndt-Jovin D J, Jovin T M
Department of Biology, University of California, Riverside 92521.
Biochemistry. 1991 Jun 25;30(25):6162-6. doi: 10.1021/bi00239a012.
The rotational diffusion of epidermal growth factor (EGF) bound to its specific receptor on the surface of human carcinoma A431 cells was studied by means of time-resolved phosphorescence anisotropy measurements. The rotational mobility was measured on the total population of EGF receptors by using a saturating concentration of EGF conjugated with a phosphorescent label, erythrosin, or on the subpopulation of high-affinity EGF receptors by using a low concentration of labeled EGF. At 4 degrees C, the rotational correlation times for both the high-affinity and total (mostly low affinity) receptor populations were in the range of 60-100 microns. Elevation of the temperature to 37 degrees C resulted in a lengthening of the rotational correlation time of the total receptor population to 200-300 microns, confirming a previous study of receptor microaggregation. The high-affinity EGF receptors were completely immobilized at 37 degrees C (rotational correlation time greater than 500 microns). The data are consistent with a model involving association of the cytoskeleton with the high-affinity receptors at 37 degrees C, but not at 4 degrees C.
通过时间分辨磷光各向异性测量法研究了与人类A431癌细胞表面特异性受体结合的表皮生长因子（EGF）的旋转扩散。通过使用与磷光标记物赤藓红偶联的饱和浓度的EGF，测量了EGF受体总群体的旋转迁移率；或者通过使用低浓度的标记EGF，测量了高亲和力EGF受体亚群体的旋转迁移率。在4℃时，高亲和力受体群体和总（主要是低亲和力）受体群体的旋转相关时间在60 - 100微秒范围内。将温度升高到37℃导致总受体群体的旋转相关时间延长至200 - 300微秒，证实了先前关于受体微聚集的研究。高亲和力EGF受体在37℃时完全固定（旋转相关时间大于500微秒）。这些数据与一个模型一致，该模型认为在37℃时细胞骨架与高亲和力受体相关联，而在4℃时则不然。
