Publication Type | Academic Article |
Authors | Buster D, Hinton J, Millett F, Shungu D |
Journal | Biophys J |
Volume | 53 |
Issue | 2 |
Pagination | 145-52 |
Date Published | 02/01/1988 |
ISSN | 0006-3495 |
Keywords | Gramicidin, Ion Channels, Lipid Bilayers, Phosphatidylcholines, Phosphatidylglycerols |
Abstract | A technique for investigating the gramicidin-facilitated transport of Na+ ions across lipid bilayers of large unilamellar vesicles under the condition of ionic equilibrium has been developed using a combination of heat incubation of the gramicidin with the vesicles and 23Na-nuclear magnetic resonance (NMR) spectroscopy. Isolation of the two 23Na-NMR signals from the intra- and extravesicular Na+ with the shift reagent, dysprosium (III) tripolyphosphate, allows the equilibrium flux of Na+ through the gramicidin channels to be detected and treated as a two-site exchange process. This study indicates that the transport of Na+ through gramicidin channels is second order with respect to the gramicidin concentration. |
DOI | 10.1016/S0006-3495(88)83076-5 |
PubMed ID | 2449917 |
PubMed Central ID | PMC1330135 |