|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ИНХС РАН |
||
Chemical and photochemical modification of colicin E1 and gramicidin a in bilayer lipid membranesстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Sobko A.A., Vigasina M.A., Rokitskaya T.I., Kotova E.A., Zakharov S.D., Cramer W.A., Antonenko Y.N.
- Журнал: Journal of Membrane Biology
- Том: 199
- Номер: 1
- Год издания: 2004
- Издательство: Springer Verlag
- Местоположение издательства: Germany
- Первая страница: 51
- Последняя страница: 62
- DOI: 10.1007/s00232-004-0674-y
- Аннотация: Chemical modification and photodynamic treatment of the colicin E1 channel-forming domain (P 178) in vesicular and planar bilayer lipid membranes (BLMs) was used to elucidate the role of tryptophan residues in colicin E1 channel activity. Modification of colicin tryptophan residues by N-bromosuccinimide (NBS), as judged by the loss of tryptophan fluorescence, resulted in complete suppression of wild-type P178 channel activity in BLMs formed from fully saturated (diphytanoyl) phospholipids, both at the macroscopic-current and single-channel levels. The similar effect on both the tryptophan fluorescence and the electric current across BLM was observed also after NBS treatment of gramicidin channels. Of the single-tryptophan P178 mutants studied, W460 showed the highest sensitivity to NBS treatment, pointing to the importance of the water-exposed Trp460 in colicin channel activity. In line with previous work, the photodynamic treatment (illumination with visible light in the presence of a photosensitizer) led to suppression of P178 channel activity in diphytanoyl-phospholipid membranes concomitant with the damage to tryptophan residues detected here by a decrease in tryptophan fluorescence. The present work revealed novel effects: activation of P178 channels as a result of both NBS and photodynamic treatments was observed with BLMs formed from unsaturated (dioleoyl) phospholipids. These phenomena are ascribed to the effect of oxidative modification of double-bond-containing lipids on P178 channel formation. The pronounced stimulation of the colicin-mediated ionic current observed after both pretreatment with NBS and sensitized photomodification of the BLMs support the idea that distortion of membrane structure can facilitate channel formation.
- Добавил в систему: Рокицкая Татьяна Ивановна