کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6493418 | 1418055 | 2018 | 33 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Creation of a 3Mn/1Fe cluster in the oxygen-evolving complex of photosystem II and investigation of its functional activity
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کلمات کلیدی
Bathophenanthroline disulfonic acidDCMUHEPESTRISDPCDCPIPPSIIOECChlBPDSTMB1,5-Diphenylcarbazide - 1،5-دیفینیل کربازید2-(N-morpholino)-ethanesulfonic acid - 2- (N-مورفولینو) -اتان سولفونیک اسید2,6-dichlorophenolindophenol - 2،6-dichlorophenolindophenol3-(3,4-Dichlorophenyl)-1,1-dimethylurea - 3- (3،4-Dichlorophenyl) -1،1-dimethylurea3,3′,5,5′-tetramethylbenzidine - 3،3 '، 5،5'-تترامیلیل بنزیدینN-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid - N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acidIron - آهنHaz - انجام دهیدTris(hydroxymethyl)aminomethane - تریس (هیدروکسی متیل) آمینومتانWater-splitting - تقسیم آبChlorophyll - سبزینه یا کلروفیلPhotosystem II - فتوسیستم 2reaction center - مرکز واکنشMeS - مسManganese - منگنز Hydroquinone - هیدروکینونOxygen-evolving complex - پیچیده اکسیژن تکامل یافتهCalcium - کلسیم
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Creation of a 3Mn/1Fe cluster in the oxygen-evolving complex of photosystem II and investigation of its functional activity Creation of a 3Mn/1Fe cluster in the oxygen-evolving complex of photosystem II and investigation of its functional activity](/preview/png/6493418.png)
چکیده انگلیسی
Extraction of Mn cations from the oxygen-evolving complex (OEC) of Ca-depleted PSII membranes (PSII[-Ca,4Mn]) by reductants like hydroquinone (H2Q) occurs with lower efficiency at acidic pH (2Mn/reaction center [RC] are extracted at pHÂ 5.7) than at neutral pH (3Mn/RC are extracted at pHÂ 6.5) [Semin et al. Photosynth. Res. 125 (2015) 95]. Fe(II) also extracts Mn cations from PSII(-Ca,4Mn), but only 2Mn/RC at pHÂ 6.5, forming a heteronuclear 2Mn/2Fe cluster [Semin and Seibert, J. Bioenerg. Biomembr. 48 (2016) 227]. Here we investigated the efficiency of Mn extraction by Fe(II) at acidic pH and found that Fe(II) cations can extract only 1Mn/RC from PSII(-Ca,4Mn) membranes at pH 5.7, forming a 3Mn/1Fe cluster. Also we found that the presence of Fe cations in a heteronuclear cluster (2Mn/2Fe) increases the resistance of the remaining Mn cations to H2Q action, since H2Q can extract Mn cations from homonuclear Mn clusters of PSII(-Ca,4Mn) and PSII(-Ca,2Mn) membranes but not from the heteronuclear cluster in PSII(-Ca,2Mn,2Fe) membranes. H2Q also cannot extract Mn from PSII membranes obtained by incubation of PSII(-Ca,4Mn) membranes with Fe(II) cations at pHÂ 5.7, which suggests the formation of a heteronuclear 3Mn/1Fe cluster in the OEC. Functional activity of PSII with a 3Mn/1Fe cluster was investigated. PSII preparations with a 3Mn/1Fe cluster in the OEC are able to photoreduce the exogenous electron acceptor 2,6-dichlorophenolindophenol, possibly due to incomplete oxidation of water molecules as is the case with PSII(-Ca,2Mn,2Fe) samples. However, in the contrast to PSII(-Ca,2Mn,2Fe) samples PSII(-Ca,3Mn,1Fe) membranes can evolve O2 at a low rate in the presence of exogenous Ca2Â + (at about 27% of the rate of O2 evolution in native PSII membranes). The explanation for this phenomenon (either water splitting and production of molecular O2 by the 3Mn/1Fe cluster or apparent O2 evolution due to minor contamination of PSII(3Mn,1Fe) samples with PSII(-Ca,4Mn) membranes) is discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 178, January 2018, Pages 192-200
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 178, January 2018, Pages 192-200
نویسندگان
B.Ð. Semin, L.N. Davletshina, M. Seibert, A.B. Rubin,