کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8299065 | 1537050 | 2009 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Investigation of the low-affinity oxidation site for exogenous electron donors in the Mn-depleted photosystem II complexes
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کلمات کلیدی
HEPESTRISDCPIPPSIIOECChlDPCDEPC1,5-Diphenylcarbazide - 1،5-دیفینیل کربازید2-(N-morpholino)-ethanesulfonic acid - 2- (N-مورفولینو) -اتان سولفونیک اسید2,6-dichlorophenolindophenol - 2،6-dichlorophenolindophenolN-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid - N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acidΔψ - ΔρIron - آهنtransmembrane electric potential difference - اختلاف پتانسیل الکتریکی فرابنفشTris(hydroxymethyl)aminomethane - تریس (هیدروکسی متیل) آمینومتانdiethylpyrocarbonate - دیاتیلپیر کربناتChlorophyll - سبزینه یا کلروفیلPhotosystem II - فتوسیستم 2Chlorophyll fluorescence - فلورسانس کلروفیلMeS - مسManganese - منگنز photovoltage - ولتاژ فتوولتائیکOxygen-evolving complex - پیچیده اکسیژن تکامل یافتهThermoluminescence - گرماتابی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In the manganese-depleted photosystem II (PSII[âMn]) preparations, oxidation of exogenous electron donors is carried out through the high-affinity (HA) and the low-affinity (LA) sites. This paper investigates the LA oxidation site in the PSII(âMn) preparations where the HA, Mn-binding site was blocked with ferric cations [[11] B.K. Semin, M.L. Ghirardi, M. Seibert, Blocking of electron donation by Mn(II) to YZ
- following incubation of Mn-depleted photosystem II membranes with Fe(II) in the light, Biochemistry 41 (2002) 5854-5864.]. In blocked (PSII[âMn,+Fe]) preparations electron donation by Mn(II) cations to YZ
- was not detected at Mn(II) concentration 10 μM (corresponds to Km for Mn(II) oxidation at the HA site), but detected at Mn concentration 100 μM (corresponds to Km for the LA site) by fluorescence measurements. Comparison of pH-dependencies of electron donation by Mn(II) through the HA and the LA sites revealed the similar ÑKа equal to 6.8. Comparison of Km for diphenylcarbazide (DPC) oxidation at the LA site and Kd for AT thermoluminescence band suppression by DPC in PSII(âMn,+Fe) samples suggests that there is relationship between the LA site and AT band formation. The role of D1-His190 as an oxidant of exogenous electron donors at the LA site is discussed. In contrast to electrogenic electron transfer from Mn(II) at the HA site to YZ
- , photovoltage due to Mn(II) oxidation in iron-blocked PSII(âMn) core particles was not detected.
- following incubation of Mn-depleted photosystem II membranes with Fe(II) in the light, Biochemistry 41 (2002) 5854-5864.]. In blocked (PSII[âMn,+Fe]) preparations electron donation by Mn(II) cations to YZ
- was not detected at Mn(II) concentration 10 μM (corresponds to Km for Mn(II) oxidation at the HA site), but detected at Mn concentration 100 μM (corresponds to Km for the LA site) by fluorescence measurements. Comparison of pH-dependencies of electron donation by Mn(II) through the HA and the LA sites revealed the similar ÑKа equal to 6.8. Comparison of Km for diphenylcarbazide (DPC) oxidation at the LA site and Kd for AT thermoluminescence band suppression by DPC in PSII(âMn,+Fe) samples suggests that there is relationship between the LA site and AT band formation. The role of D1-His190 as an oxidant of exogenous electron donors at the LA site is discussed. In contrast to electrogenic electron transfer from Mn(II) at the HA site to YZ
- , photovoltage due to Mn(II) oxidation in iron-blocked PSII(âMn) core particles was not detected.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1787, Issue 12, December 2009, Pages 1492-1498
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1787, Issue 12, December 2009, Pages 1492-1498
نویسندگان
V.N. Kurashov, E.R. Lovyagina, D.Yu. Shkolnikov, M.K. Solntsev, M.D. Mamedov, B.K. Semin,