Composition and regulation of thylakoid membrane of Antarctic ice microalgae Chlamydomonas sp. ICE-L in response to low-temperature environment stress

2016 ◽  
Vol 97 (6) ◽  
pp. 1241-1249 ◽  
Author(s):  
Wang Yi-Bin ◽  
Liu Fang-Ming ◽  
Zhang Xiu-Fang ◽  
Zhang Ai-Jun ◽  
Wang Bin ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Protein Complexes ◽  
Thylakoid Membranes ◽  
Ice Algae ◽  
Stress Concentrations ◽  
Light Harvesting Complex ◽  
Pigment Protein Complexes ◽  
Environment Stress ◽  
The Antarctic

Ice algae have successfully adapted to the extreme environmental conditions in the Antarctic, however the underlying mechanisms involved in the regulation and response of thylakoid membranes and chloroplast to low-temperature stress are still not well understood. In this study, changes in pigment concentrations, lipids, fatty acids and pigment protein complexes in thylakoid membranes and chloroplast after exposure to low temperature conditions were investigated using the Antarctic ice algae Chlamydomonas sp. ICE-L. Results showed that the chloroplasts of Chlamydomonas sp. ICE-L are distributed throughout the cell except in the nuclear region in the form of thylakoid lamellas which exists in the gap between organelles and the starch granules. Also, the structure of mitochondria has no obvious change after cold stress. Concentrations of Chl a, Chl b, monogalactosyl diacylglycerol, digalactosyl diacylglycerol and fatty acids were also observed to exhibit changes with temperature, suggesting possible adaptations to cold environments. The light harvesting complex, lutein and β-carotene played an important role for adaptation of ICE-L, and increasing of monogalactosyl diacylglycerol and digalactosyl diacylglycerol improved the overall degree of unsaturation of thylakoid membranes, thereby maintaining liquidity of thylakoid membranes. The pigments, lipids, fatty acids and pigment-protein complexes maintained the stability of the thylakoid membranes and the normal physiological function of Chlamydomonas sp. ICE-L.

scholarly journals Structure of the stress-related LHCSR1 complex determined by an integrated computational strategy

2021 ◽  
Author(s):  
Ingrid Guarnetti Prandi ◽  
Vladislav Sláma ◽  
Cristina Pecorilla ◽  
Lorenzo Cupellini ◽  
Benedetta Mennucci
Keyword(s):  
Structural Model ◽  
Light Harvesting ◽  
Structural Information ◽  
Protein Complexes ◽  
Complex Stress ◽  
Main Function ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Pigment Protein Complexes ◽  
Computational Strategy

Light-harvesting complexes (LHCs) are pigment-protein complexes whose main function is to capture sunlight and transfer the energy to reaction centers of photosystems. In response to varying light conditions, LH complexes also play photoregulation and photoprotection roles. In algae and mosses, a sub-family of LHCs, Light-Harvesting complex stress related (LHCSR), is responsible for photoprotective quenching. Despite their functional and evolutionary importance, no direct structural information on LHCSRs is available that can explain their unique properties. In this work we propose a structural model of LHCSR1 from the moss P. Patens, obtained through an integrated computational strategy that combines homology modeling, molecular dynamics, and multiscale quantum chemical calculations. The model is validated by reproducing the spectral properties of LHCSR1. Our model reveals the structural specificity of LHCSR1, as compared with the CP29 LH complex, and poses the basis for understanding photoprotective quenching in mosses.

scholarly journals Contribution of low-temperature single-molecule techniques to structural issues of pigment–protein complexes from photosynthetic purple bacteria

2018 ◽  
Vol 15 (138) ◽  
pp. 20170680 ◽  
Author(s):  
Alexander Löhner ◽  
Richard Cogdell ◽  
Jürgen Köhler
Keyword(s):  
Low Temperature ◽  
Single Molecule ◽  
Degrees Of Freedom ◽  
Protein Complexes ◽  
Purple Bacteria ◽  
Structural Models ◽  
Spectral Features ◽  
Light Harvesting Complexes ◽  
Pigment Protein Complexes ◽  
Photosynthetic Purple Bacteria

As the electronic energies of the chromophores in a pigment–protein complex are imposed by the geometrical structure of the protein, this allows the spectral information obtained to be compared with predictions derived from structural models. Thereby, the single-molecule approach is particularly suited for the elucidation of specific, distinctive spectral features that are key for a particular model structure, and that would not be observable in ensemble-averaged spectra due to the heterogeneity of the biological objects. In this concise review, we illustrate with the example of the light-harvesting complexes from photosynthetic purple bacteria how results from low-temperature single-molecule spectroscopy can be used to discriminate between different structural models. Thereby the low-temperature approach provides two advantages: (i) owing to the negligible photobleaching, very long observation times become possible, and more importantly, (ii) at cryogenic temperatures, vibrational degrees of freedom are frozen out, leading to sharper spectral features and in turn to better resolved spectra.

Strong light-induced reorganization of pigment–protein complexes of thylakoid membranes in rye (spectroscopic study)

2012 ◽  
Vol 169 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Ewa Janik ◽  
Waldemar Maksymiec ◽  
Wojciech Grudziński ◽  
Wiesław I. Gruszecki
Keyword(s):  
Spectroscopic Study ◽  
Protein Complexes ◽  
Thylakoid Membranes ◽  
Strong Light ◽  
Pigment Protein Complexes

scholarly journals Differential Mobility of Pigment-Protein Complexes in Granal and Agranal Thylakoid Membranes of C3 and C4 Plants

2012 ◽  
Vol 161 (1) ◽  
pp. 497-507 ◽  
Author(s):  
Helmut Kirchhoff ◽  
Richard M. Sharpe ◽  
Miroslava Herbstova ◽  
Robert Yarbrough ◽  
Gerald E. Edwards
Keyword(s):  
Protein Complexes ◽  
Thylakoid Membranes ◽  
C4 Plants ◽  
C3 And C4 Plants ◽  
Differential Mobility ◽  
Pigment Protein Complexes

Chlorophyll Photobleaching in Pigment-Protein Complexes

1986 ◽  
Vol 41 (3) ◽  
pp. 284-290 ◽  
Author(s):  
Robert Carpentier ◽  
Roger M. Leblanc ◽  
Guy Bellemare
Keyword(s):  
Energy Transfer ◽  
Hordeum Vulgare ◽  
Chlamydomonas Reinhardtii ◽  
Protein Complexes ◽  
Thylakoid Membranes ◽  
Wild Type ◽  
Protection Mechanism ◽  
Long Wavelength ◽  
Pigment Protein Complexes ◽  
Type Mutant

Pigment photobleaching was performed in thylakoid membranes of Hordeum vulgare (wild type, mutant Chlorina f2, Norfluranzon treated seedlings) and in pigment-protein complexes (CP-I and LHCP) isolated from H. vulgare and Chlamydomonas reinhardtii. Multiphasic kinetics were obtained in all of the above cases. Energy transfer towards pigments absorbing at longer wavelength is postulated as a general protection mechanism against photobleaching. This mechanism explains a substantial bleaching of carotenoids and a faster bleaching of chlorophyll aggregates, absorbing at long wavelength. These conclusions were valid for isolated complexes as well as for thylakoid membranes, although membranes were less sensitive to light.

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