A piston model for transmembrane signaling of the aspartate receptor
A piston model for transmembrane signaling of the aspartate receptor
复制标题
DOI：
10.1126/science.285.5434.1751
复制
发表时间：
1999-09-10
期刊：
影响因子：
56.9
通讯作者：
Koshland, DE
中科院分区：
文献类型：
--
作者：
Ottemann, KM;Xiao, WZ;Koshland, DE
为了表征受体跨膜传播构象变化的机制，在细菌天冬氨酸受体的关键位置贴上了氮氧化物自旋标记。通过收集这些标记受体在有无配体天冬氨酸的情况下的电子顺磁共振光谱，配体结合被证明产生了类似于1埃的亚基内活塞式运动，一个跨膜螺旋相对于另一个跨膜螺旋向下移动。受体相关的磷酸化级联蛋白CHEA和CHEW不改变配体诱导的运动。由于活塞运动非常小，受体对刺激的反应产生巨大结果的能力是由受体偶联酶检测受体构象的微小变化造成的。
To characterize the mechanism by which receptors propagate conformational changes across membranes, nitroxide spin labels were attached at strategic positions in the bacterial aspartate receptor. By collecting the electron paramagnetic resonance spectra of these labeled receptors in the presence and absence of the Ligand aspartate, ligand binding was shown to generate an similar to 1 angstrom intrasubunit piston-type movement of one transmembrane helix downward relative to the other transmembrane helix. The receptor-associated phosphorylation cascade proteins CheA and CheW did not alter the ligand-induced movement. Because the piston movement is very small, the ability of receptors to produce Large outcomes in response to stimuli is caused by the ability of the receptor-coupled enzymes to detect small changes in the conformation of the receptor.