Cafiso D S, Hubbell W L
Biochemistry. 1978 Jan 10;17(1):187-95. doi: 10.1021/bi00594a028.
Positively charged hydrophobic spin labels have been synthesized which respond to transmembrane potentials in sonicated liposomes. Electron paramagnetic resonance spectroscopy is used to show that the distribution of these probes between aqueous and membrane phases changes as a function of transmembrane potential. When liposomes are made more inside-negative, the fraction of membrane associated probe increases while the fraction of probe in the aqueous phase decreases. The results are in quantitative agreement with a simple equilibrium thermodynamic theory which allows estimation of absolute transmembrane potentials in phospholipid vesicles.
已经合成了带正电荷的疏水性自旋标记物，它们对超声处理的脂质体中的跨膜电位有响应。电子顺磁共振光谱用于表明这些探针在水相和膜相之间的分布随跨膜电位而变化。当脂质体内部变得更负时，与膜结合的探针比例增加，而水相中探针的比例降低。结果与简单的平衡热力学理论在定量上一致，该理论允许估计磷脂囊泡中的绝对跨膜电位。
