Investigation of the interaction between thallous ions and gramicidin A in dimyristoylphosphatidylcholine vesicles: a thallium-205 NMR equilibrium study.
| 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 |