Monoi H, Uedaira H
Biophys J. 1979 Mar;25(3):535-40. doi: 10.1016/S0006-3495(79)85321-7.
23Na nuclei in a milk-white emulsion composed to nonionic surfactant and higher alcohol in saline were characterized by single values of T1 and T2 and a single Larmor frequency. In the presence of small amounts of gramicidin D (Dubos), the relaxations of 23Na were greatly accelerated, and the transverse relaxation was a sum of two decaying exponentials. But only a single T1 was observed; it was roughly equal to the slow T2. The slow T2 accounted for about 40% of the total resonance intensity. The relaxation rates increased linearly with the increase of the gramicidin concentration. The absorption signal consisted of a narrow and a broad line, both centered at the same frequency. The present results suggest that nuclear magnetic resonance spectroscopy is a useful tool for studying the nature of ion-permeable channels of biological membranes, even when the channel has no ionizable groups.
在由非离子表面活性剂和高级醇组成的乳白色乳液中，23Na原子核在盐溶液中的T1和T2值单一，拉莫尔频率也单一。在存在少量短杆菌肽D（杜博斯）的情况下，23Na的弛豫大大加速，横向弛豫是两个衰减指数的总和。但只观察到一个单一的T1；它大致等于较慢的T2。较慢的T2约占总共振强度的40%。弛豫率随短杆菌肽浓度的增加而线性增加。吸收信号由一条窄线和一条宽线组成，两者都以相同频率为中心。目前的结果表明，核磁共振光谱是研究生物膜离子渗透通道性质的有用工具，即使该通道没有可电离基团。
