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. 1979 Mar;25(3):535–540. doi: 10.1016/S0006-3495(79)85321-7

Na+ interacting with gramicidin D. A nuclear magnetic resonance study.

H Monoi, H Uedaira
PMCID: PMC1328489  PMID: 95566

Abstract

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.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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