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Lipid Polymorphism of the Subchloroplast-Granum and Stroma Thylakoid Membrane-Particles. II. Structure and Functions
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SYSNO ASEP 0549353 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Lipid Polymorphism of the Subchloroplast-Granum and Stroma Thylakoid Membrane-Particles. II. Structure and Functions Author(s) Dlouhý, O. (CZ)
Karlický, Václav (UEK-B) ORCID, RID, SAI
Rameez, A. (CZ)
Zsiros, O. (HU)
Domonkos, I. (HU)
Kurasová, Irena (UEK-B)
Wacha, A. F. (HU)
Morosinotto, T. (IT)
Bota, A. (HU)
Kouřil, R. (CZ)
Špunda, Vladimír (UEK-B) ORCID, SAI, RID
Garab, G. (HU)Number of authors 11 Article number 2363 Source Title Cells. - : MDPI
Roč. 10, č. 9 (2021)Number of pages 19 s. Publication form Print - P Language eng - English Country CH - Switzerland Keywords light-harvesting-complex ; violaxanthin de-epoxidase ; photosystem-ii ; nonbilayer lipids ; induced detachment ; thermal-stability ; respiratory-chain ; phase-behavior ; higher-plants ; atp synthase ; bilayer ; chlorophyll fluorescence ; cryo-electron-tomography ; electron microscopy ; membrane energization ; membrane networks ; non-bilayer lipid phases ; saxs ; violaxanthin de-epoxidase Subject RIV BO - Biophysics OECD category Biophysics R&D Projects EF16_019/0000797 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) LM2018123 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) Research Infrastructure CzeCOS III - 90123 - Ústav výzkumu globální změny AV ČR, v. v. i. Method of publishing Open access Institutional support UEK-B - RVO:86652079 UT WOS 000699266100001 EID SCOPUS 85115889056 DOI 10.3390/cells10092363 Annotation In Part I, by using P-31-NMR spectroscopy, we have shown that isolated granum and stroma thylakoid membranes (TMs), in addition to the bilayer, display two isotropic phases and an inverted hexagonal (H-II) phase, saturation transfer experiments and selective effects of lipase and thermal treatments have shown that these phases arise from distinct, yet interconnectable structural entities. To obtain information on the functional roles and origin of the different lipid phases, here we performed spectroscopic measurements and inspected the ultrastructure of these TM fragments. Circular dichroism, 77 K fluorescence emission spectroscopy, and variable chlorophyll-a fluorescence measurements revealed only minor lipase- or thermally induced changes in the photosynthetic machinery. Electrochromic absorbance transients showed that the TM fragments were re-sealed, and the vesicles largely retained their impermeabilities after lipase treatments-in line with the low susceptibility of the bilayer against the same treatment, as reflected by our P-31-NMR spectroscopy. Signatures of H-II-phase could not be discerned with small-angle X-ray scattering-but traces of H-II structures, without long-range order, were found by freeze-fracture electron microscopy (FF-EM) and cryo-electron tomography (CET). EM and CET images also revealed the presence of small vesicles and fusion of membrane particles, which might account for one of the isotropic phases. Interaction of VDE (violaxanthin de-epoxidase, detected by Western blot technique in both membrane fragments) with TM lipids might account for the other isotropic phase. In general, non-bilayer lipids are proposed to play role in the self-assembly of the highly organized yet dynamic TM network in chloroplasts. Workplace Global Change Research Institute Contact Nikola Šviková, svikova.n@czechglobe.cz, Tel.: 511 192 268 Year of Publishing 2022 Electronic address https://www.mdpi.com/2073-4409/10/9/2363
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