Woolley G A, Deber C M
Biopolymers. 1989 Jan;28(1):267-72. doi: 10.1002/bip.360280127.
A membrane potential is shown to be established in phosphatidylcholine/cholesterol unilamellar vesicles using valinomycin in conjunction with a potassium ion gradient; this potential is monitored using the externally added fluorescent dye Safranine O. In the same system, transmembrane calcium fluxes are then detected using the (internally trapped) fluorescent dye Quin-2. The calcium-transport behavior of the channel-forming peptide alamethicin is shown to be potential dependent in this system, in contrast to calcium transport by the ionophore Br-A23187, which is unaffected by the potential. The observation of this potential-dependent behavior for alamethicin suggests that this vesicle system may be suitable for direct spectroscopic observation of the voltage-gating process.
已证明，使用缬氨霉素并结合钾离子梯度，可在磷脂酰胆碱/胆固醇单层囊泡中建立膜电位；该电位通过外部添加的荧光染料藏红O进行监测。在同一系统中，然后使用（内部捕获的）荧光染料喹啉-2检测跨膜钙通量。与离子载体溴-A23187的钙转运不受电位影响相反，在该系统中，成孔肽短杆菌肽A的钙转运行为显示出电位依赖性。对短杆菌肽A这种电位依赖性行为的观察表明，该囊泡系统可能适用于电压门控过程的直接光谱观察。
