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
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