Boheim G, Hanke W, Barrantes F J, Eibl H, Sakmann B, Fels G, Maelicke A
Proc Natl Acad Sci U S A. 1981 Jun;78(6):3586-90. doi: 10.1073/pnas.78.6.3586.
Planar lipid bilayers were formed with the mixed chain phospholipid 1-stearoyl-3-myristolglycero-2-phosphocholine. Acetylcholine receptor membrane fragments or the purified receptor protein was incorporated into these bilayers by fusing receptor-containing vesicles with the planar membranes a few degrees below the lipid phase transition temperature. Single-channel currents activated by nicotinic agonists in the reconstituted system resembled those observed in intact rat and frog muscle membrane as measured by the patch clamp technique. The observed channel characteristics did not depend on the degree of receptor purification. Thus, the receptor-enriched fragments and those depleted of nonreceptor peripheral peptides, the purified receptor monomer/dimer mixtures, and the isolated receptor monomer as defined by gel electrophoresis all shared similar electrochemical properties in the synthetic lipid bilayer. The agonist-activated ionic channel seems, therefore, to be contained within the receptor monomer.
平面脂质双层由混合链磷脂1-硬脂酰-3-肉豆蔻酰甘油-2-磷酸胆碱形成。通过在低于脂质相变温度几度的情况下将含受体的囊泡与平面膜融合，将乙酰胆碱受体膜片段或纯化的受体蛋白整合到这些双层中。通过膜片钳技术测量，在重构系统中由烟碱激动剂激活的单通道电流类似于在完整大鼠和青蛙肌肉膜中观察到的电流。观察到的通道特性不依赖于受体纯化程度。因此，富含受体的片段和那些去除了非受体外周肽的片段、纯化的受体单体/二聚体混合物以及凝胶电泳定义的分离受体单体在合成脂质双层中都具有相似的电化学性质。因此，激动剂激活的离子通道似乎包含在受体单体中。
