The relation between lipid mobility and the specific hormone binding of thyroid membranes.
The relation between lipid mobility and the specific hormone binding of thyroid membranes.
复制标题
脂质流动性与甲状腺膜特异性激素结合之间的关系。
作者：
C. Bashford;S. Harrison;G. Radda
1.在各种条件下，研究了促甲状腺激素与离体人甲状腺膜的特异性结合。2.在磷酸盐-盐水缓冲液中（在0.14 M-NaCl存在下），随着温度的升高，激素的结合增加，结合/游离激素对温度的曲线显示出在30 ℃左右的明显中断。3.详细的分析表明，结合的增加与结合位点数量的增加有关。4. 3个膜结合荧光探针，2-（9-蒽基）棕榈酸，12-（9-蒽基）硬脂酸和N-1-萘基-N-苯胺的运动特性，也被检查作为温度的函数，通过测量荧光偏振和寿命。5.结果表明，膜脂的“流动性”也随着温度的升高而增加。该性质的温度依赖性也显示出在约30摄氏度处的变化。6.二价阳离子降低膜流动性和激素结合。7.在促肾上腺皮质激素的结合和从肾上腺皮质细胞获得的质膜的流动性之间也发现了类似的相关性，在这种情况下，在23摄氏度下出现了不连续性。8.脂质流动性的可能性是重要的控制受体功能进行了讨论。
1. The specific binding of thyroid-stimulating hormone to isolated human thyroid membranes was examined under a variety of conditions. 2. In phosphate-saline buffer (in the presence of 0.14 M-NaCl) on increasing the temperature the binding of the hormone is increased, the plots of bound/free hormone against temperature showing a distinct break around 30 degrees C. 3. Detailed analysis showed that the increased binding is associated with an increase in the number of binding sites. 4. The motional characteristics of three membrane-bound fluorescent probes, 2-(9-anthroyl)palmitic acid, 12-(9-anthryl)stearic acid and N-1-naphthyl-N-phenylamine, were also examined as a function of temperature by measuring both fluorescence polarizations and lifetimes. 5. The results indicated that the 'fluidity' of membrane lipids also increased with temperature. The temperature-dependence of this property also shows a change at about 30 degrees C. 6. Bivalent cations decreased both membrane fluidity and hormone binding. 7. Similar correlations were found between the binding of adrenocorticotrophic hormone and the fluidity of the plasma membranes obtained from adrenal-cortical cells, with the discontinuity occurring in this case at 23 degrees C. 8. The possibility of lipid mobility being important in controlling hormone-receptor function is discussed.