Mazella J, Kwan C Y, Kitabgi P, Vincent J P
Peptides. 1985 Nov-Dec;6(6):1137-41. doi: 10.1016/0196-9781(85)90440-1.
Neurotensin receptors from plasma membranes of rat gastric fundus smooth muscle were specifically and covalently labeled either by using the photoreactive analogue 125I-labeled azidobenzoyl (Trp11)-neurotensin or by cross-linking (monoiodo-Tyr3)neurotensin to the membrane preparation by means of disuccinimidyl suberate. Analysis of plasma membranes by sodium dodecylsulfate-polyacrylamide gel electrophoresis and autoradiography revealed that the same protein band with an apparent molecular weight of 110,000 was specifically labeled by both methods. This band consisted of a single chain protein since its apparent size was found to be the same with or without reduction of membrane samples before electrophoresis. Only neurotensin and its biologically active analogues were able to protect plasma membranes against specific labeling of the protein band of molecular weight 110,000. Comparison of these results with those obtained from rat brain synaptic membranes shows that although rat central and peripheral neurotensin receptors exhibit similar specificities towards a series of neurotensin analogues, their subunit structures are different.
通过使用光反应性类似物125I标记的叠氮苯甲酰（色氨酸11）-神经降压素，或者通过借助辛二酸二琥珀酰亚胺酯将（单碘酪氨酸3）神经降压素与膜制剂交联，对大鼠胃底平滑肌质膜上的神经降压素受体进行特异性共价标记。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和放射自显影对质膜进行分析，结果显示两种方法特异性标记的是同一条表观分子量为110,000的蛋白带。该条带由单链蛋白组成，因为在电泳前对膜样品进行还原或不还原处理时，其表观大小相同。只有神经降压素及其生物活性类似物能够保护质膜不被分子量为110,000的蛋白带特异性标记。将这些结果与从大鼠脑突触膜获得的结果进行比较表明，尽管大鼠中枢和外周神经降压素受体对一系列神经降压素类似物表现出相似的特异性，但其亚基结构不同。
