Publication Type | Academic Article |
Authors | Shungu D, Hinton J, Koeppe R, Millett F |
Journal | Biochemistry |
Volume | 25 |
Issue | 20 |
Pagination | 6103-8 |
Date Published | 10/07/1986 |
ISSN | 0006-2960 |
Keywords | Dimyristoylphosphatidylcholine, Gramicidin, Liposomes, Thallium |
Abstract | This study reports the first direct observation of multiple occupancy of the gramicidin A channel by Tl+ ions. 205Tl NMR has been used to study the equilibrium binding of Tl+ by gramicidin A incorporated in sonicated dimyristoylphosphatidylcholine vesicles. It is shown that only multiple-channel occupancy can account for the 205Tl chemical shifts measured. The data are analyzed to yield the equilibrium association constants of 450-600 and 5-20 M-1 for the binding of the first and the second ions at 34 degrees C, respectively. |
DOI | 10.1021/bi00368a040 |
PubMed ID | 2431708 |