کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8292334 | 1536727 | 2018 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Electrogenic reactions in Mn-depleted photosystem II core particles in the presence of synthetic binuclear Mn complexes
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
An electrometrical technique was used to investigate electron transfer between synthetic binuclear manganese (Mn) complexes, designated Mâ¯ââ¯2 and Mâ¯ââ¯3, and the redox-active neutral tyrosine radical (YZ
- ) in proteoliposomes containing Mn-depleted photosystem II (PS II) core particles in response to single laser flashes. In the absence of Mn-containing compounds, the observed flash-induced membrane potential (ÎΨ) decay was mainly due to charge recombination between the reduced primary quinone acceptor QAâ and the oxidized YZ
- . More significant slowing down of the ÎΨ decay in the presence of lower concentrations of Mâ¯ââ¯2 and Mâ¯ââ¯3 associated with electron donation from Mn in the Mn-binding site to YZ
- indicates that these synthetic compounds are more effective electron donors than MnCl2. The exponential fitting of the kinetics of additional electrogenic components of ÎΨ rise in the presence of Mn-containing compounds revealed the following relative amplitudes (A) and lifetimes (Ï): for MnCl2 - Aâ¼ 3.5, Ïâ¼150â¯Î¼s, for Mâ¯ââ¯2 - Aâ¼5%, Ïâ¼1.4â¯ms, and for Mâ¯ââ¯3 - Aâ¼5.5%, Ïâ¼150â¯Î¼s. This suggests that the efficiency of the manganese complexes in electron donation depends on the chemical nature of ligands. The experiments with EDTA-treated samples indicated that the ligands for Mâ¯ââ¯2 and Mâ¯ââ¯3 are required for their tight binding with the PS II reaction center. The obtained results demonstrate the importance of understanding the molecular mechanism(s) of flash-induced electrogenic reduction of the tyrosine radical YZ
- by synthetic Mn complexes capable of splitting water into oxygen and reducing equivalents.
- ) in proteoliposomes containing Mn-depleted photosystem II (PS II) core particles in response to single laser flashes. In the absence of Mn-containing compounds, the observed flash-induced membrane potential (ÎΨ) decay was mainly due to charge recombination between the reduced primary quinone acceptor QAâ and the oxidized YZ
- . More significant slowing down of the ÎΨ decay in the presence of lower concentrations of Mâ¯ââ¯2 and Mâ¯ââ¯3 associated with electron donation from Mn in the Mn-binding site to YZ
- indicates that these synthetic compounds are more effective electron donors than MnCl2. The exponential fitting of the kinetics of additional electrogenic components of ÎΨ rise in the presence of Mn-containing compounds revealed the following relative amplitudes (A) and lifetimes (Ï): for MnCl2 - Aâ¼ 3.5, Ïâ¼150â¯Î¼s, for Mâ¯ââ¯2 - Aâ¼5%, Ïâ¼1.4â¯ms, and for Mâ¯ââ¯3 - Aâ¼5.5%, Ïâ¼150â¯Î¼s. This suggests that the efficiency of the manganese complexes in electron donation depends on the chemical nature of ligands. The experiments with EDTA-treated samples indicated that the ligands for Mâ¯ââ¯2 and Mâ¯ââ¯3 are required for their tight binding with the PS II reaction center. The obtained results demonstrate the importance of understanding the molecular mechanism(s) of flash-induced electrogenic reduction of the tyrosine radical YZ
- by synthetic Mn complexes capable of splitting water into oxygen and reducing equivalents.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 503, Issue 1, 3 September 2018, Pages 222-227
Journal: Biochemical and Biophysical Research Communications - Volume 503, Issue 1, 3 September 2018, Pages 222-227
نویسندگان
Liya A. Vitukhnovskaya, Sergey K. Zharmukhamedov, Mahdi M. Najafpour, Suleyman I. Allakhverdiev, Alexey Yu Semenov, Mahir D. Mamedov,