|
ИСТИНА |
Войти в систему Регистрация |
Интеллектуальная Система Тематического Исследования НАукометрических данных |
||
Photosynthetic electrogenic events in native membranes of Chloroflexus aurantiacus. Flash-induced charge displacements in the acceptor quinone complex of the photosynthetic reaction centerстатья
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: Mulkidjanian A.Y., Hochkoeppler A., Zannoni D., Drachev L.A., Melandri B.A., Venturoli G.
- Журнал: Photosynthesis Research
- Том: 56
- Номер: 1
- Год издания: 1998
- Издательство: Springer Nature
- Местоположение издательства: Switzerland
- Первая страница: 75
- Последняя страница: 82
- DOI: 10.1023/A:1005962401859
- Аннотация: The thermophilic phototroph Chloroflexus aurantiacus possesses a photosynthetic reaction center (RC) containing a pair of menaquinones acting as primary (MQ(A)) and secondary (MQ(B)) electron accepters and a tetraheme cytochrome c(554) as an electron donor. We used native, chlorosome-containing photosynthetic membranes of this bacterium to study the MQB turnover. The binary oscillations of the semiquinone form MQ(B)(-) in response to a train of short light flashes were monitored at 416 nm, in the isosbestic point of the light-induced difference spectrum of cytochrome c(554) After the first flash MQB- was formed, after the second one it disappeared due to the MQ(A)(-)MQ(B)(-) --> MQ(A)MQ(B)H(2) transition. The latter reaction was kinetically resolved by means of electrometry. For this purpose chromatophores of Chl. aurantiacus were adsorbed onto a phospholipid and menaquinone-impregnated collodion him. We found that after the second excitation flash, but not after the first one, the photoelectric response included, in addition to the fast kinetic components reflecting the charge separation between the tetraheme cytochrome c and MQA, a slower kinetic component with a rise time of 3 mu s (pH = 8.3) and a relative amplitude of about 10% of the charge separation phase in the RC, We attributed this reaction to the electrogenic proton transfer which accompanied the transfer of the second electron during the MQ(A)(-)MQ(B)(-) --> MQ(A)MQ(B)H(2) transition. The rise time of the same reaction was reported to be almost three orders of magnitude slower in the isolated, proteoliposome-incorporated RC from this bacterium. The possible reasons of the faster turnover rates observed in the chlorosome-carrying native membrane preparations from Chl. aurantiacus are discussed.
- Добавил в систему: Мулкиджанян Армен Яковлевич