کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1317094 1499481 2007 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
In vivo bicarbonate requirement for water oxidation by Photosystem II in the hypercarbonate-requiring cyanobacterium Arthrospira maxima
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
In vivo bicarbonate requirement for water oxidation by Photosystem II in the hypercarbonate-requiring cyanobacterium Arthrospira maxima
چکیده انگلیسی

While the presence of inorganic carbon in the form of (bi)carbonate has been known to be important for activity of Photosystem II (PSII), the vast majority of studies on this “bicarbonate effect” have been limited to in vitro studies of isolated thylakoid membranes and PSII complexes. Here we report an in vivo requirement for bicarbonate that is both reversible and selective for this anion for efficient water oxidation activity in the hypercarbonate-requiring cyanobacterium Arthrospira (Spirulina) maxima  , originally isolated from highly alkaline soda lakes. Using a non-invasive internal probe of PSII charge separation (variable fluorescence), primary electron acceptor (QA-/QA) reoxidation rate, and flash-induced oxygen yield, we report the largest reversible bicarbonate effect on PSII activity ever observed, which is due to the requirement for bicarbonate at the water-oxidizing complex. Temporal separation of this donor side bicarbonate requirement from a smaller effect of bicarbonate on the QA- reoxidation rate was observed. We expect the atypical way in which Arthrospira manages intracellular pH, sodium, and inorganic carbon concentrations relative to other cyanobacteria is responsible for this strong in vivo bicarbonate requirement.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Inorganic Biochemistry - Volume 101, Issues 11–12, November 2007, Pages 1865–1874
نویسندگان
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