کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8298750 | 1537042 | 2015 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
PSI-LHCI of Chlamydomonas reinhardtii: Increasing the absorption cross section without losing efficiency
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کلمات کلیدی
LHCIPMSDASPSIChlamydomonas reinhardtiiChlEASSASArabidopsis thaliana - آرابیدوپسیس تالیاناExcitation energy transfer - انتقال انرژی هیجان انگیزCharge separation - جداسازی شارژEET - خوردنCircular-dichroism - دایرهروی دایره ایRoom temperature - دمای اتاقTrapping efficiency - راندمان ترافیکیDecay associated spectra - طیف مربوطه را کاهش دهیدphotosystem I - عکس سیستم منTime-resolved fluorescence - فلورسانس حل شده در زمانCAR - ماشینreaction center - مرکز واکنشlight-harvesting complex I - پیچیده برداشت پیچیده ICarotenoids - کاروتنوئیدهاChlorophylls - کلروفیل
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Photosystem I (PSI) is an essential component of photosynthetic membranes. Despite the high sequence and structural homologies, its absorption properties differ substantially in algae, plants and cyanobacteria. In particular it is characterized by the presence of low-energy chlorophylls (red forms), the number and the energy of which vary in different organisms. The PSI-LHCI (PSI-light harvesting complex I) complex of the green alga Chlamydomonas reinhardtii (C.r.) is significantly larger than that of plants, containing five additional light-harvesting complexes (together binding â 65 chlorophylls), and contains red forms with higher energy than plants. To understand how these differences influence excitation energy transfer and trapping in the system, we studied two PSI-LHCI C.r. particles, differing in antenna size and red-form content, using time-resolved fluorescence and compared them to plant PSI-LHCI. The excited state kinetics in C.r. shows the same average lifetime (50 ps) as in plants suggesting that the effect of antenna enlargement is compensated by higher energy red forms. The system equilibrates very fast, indicating that all Lhcas are well-connected, despite their long distance to the core. The differences between C.r. PSI-LHCI with and without Lhca2 and Lhca9 show that these Lhcas bind red forms, although not the red-most. The red-most forms are in (or functionally close to) other Lhcas and slow down the trapping, but hardly affect the quantum efficiency, which remains as high as 97% even in a complex that contains 235 chlorophylls.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1847, Issues 4â5, AprilâMay 2015, Pages 458-467
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1847, Issues 4â5, AprilâMay 2015, Pages 458-467
نویسندگان
Clotilde Le Quiniou, Lijin Tian, Bartlomiej Drop, Emilie Wientjes, Ivo H.M. van Stokkum, Bart van Oort, Roberta Croce,