scholarly journals ИССЛЕДОВАНИЕ ФОТОХИМИЧЕСКИХ СВОЙСТВ И ФИЛОГЕНИИ РАСТИТЕЛЬНЫХ БЕЛКОВ СЕМЕЙСТВА WSCP

2020 ◽  
Vol 3 (11(80)) ◽  
pp. 38-43
Author(s):  
Yu. Obuhov ◽  
K. Neverov ◽  
Yu. Maleeva ◽  
M. Krickij
Keyword(s):  
Search Algorithm ◽  
Protein Complexes ◽  
Red Light ◽  
Bioinformatic Analysis ◽  
Class Ii ◽  
Photochemical Activity ◽  
Water Soluble ◽  
Pigment Protein Complexes ◽  
Chlorophyll Protein Complexes ◽  
The Difference

Here we show the ability of the chlorophyll associated with proteins of the WSCP family (Water-Soluble Chlorophyll-binding Proteins) to photosensitize oxidative redox reactions. Irradiation with red light of the recombinant chlorophyll-protein complexes WSCP subclasses IIa and IIb in the presence of an electron donor (NADH) led to oxidation of the donor, i.e., these pigment-protein complexes showed photochemical activity. Meanwhile there was no photodestruction of chlorophyll associated with WSCP, which indicates the photocatalytic nature of the detected redox reaction. The kinetic constants of NADH photooxidation were higher for WSCP subclass IIa (BoWSCP) than for subclass IIb (LvWSCP). To explain the difference in the photosensitizing activity of representatives of different WSCP subclasses, bioinformatic analysis of class II proteins of this family was carried out. For this purpose, we searched for members of the WSCP family in the UniProt protein sequence database using the BLAST search algorithm, followed by their multiple alignment and construction of a phylogenetic tree using the EMBL-EBI Clustal Omega web service and the MEGA7 program. Bioinformatic analysis has confirmed the phylogenetic division of the WSCP class II protein family into two subclasses, previously established on the basis of the difference in their physicochemical properties. It was suggested that phylogeny is related to the photochemical activity of representatives of different subclasses in the WSCP family.

scholarly journals Thermal Stress, Aggregation of Chlorophyll-Protein Complexes, and Light-Dependent Recovery of PSII activity in Wheat Seedlings

2021 ◽  
Vol 68 (5) ◽  
pp. 867-872
Author(s):  
M. S. Khristin ◽  
T. N. Smolova ◽  
V. D. Kreslavski
Keyword(s):  
Low Temperature ◽  
Structural Changes ◽  
Protein Complexes ◽  
Red Light ◽  
Photochemical Activity ◽  
Wheat Seedlings ◽  
Psii Activity ◽  
Temperature Spectra ◽  
Chlorophyll Protein Complexes ◽  
Chlorophyll Protein

Abstract The dynamics of changes in the photochemical activity of photosystem II (PSII) and low-temperature spectra at 77 K in the first leaves of 11-day winter wheat plants Triticum aestivum L., as well as structural changes in chlorophyll-protein complexes (CPC) of thylakoid membranes during recovery after a short-term (20 min) heating at a temperature of 42°C, were studied. Changes in the Fv/Fm, F735/F695, and F735/F685 ratios indicate inhibition of PSII immediately after heating. Using nondenaturing electrophoresis, it was shown that the light-harvesting Chl a/b complex of PSII does not aggregate immediately after heating but after several hours, after 6 h the desagregation of CPC was observed, which was consistent with an increase in the Fv/Fm ratio upon recovery. The influence of temperature, intensity, and quality of light (white, blue, and red light) on the recovery of PSII activity and low-temperature fluorescence spectra was studied. It was concluded that the recovery is a photo-activated low-energy process, independent of photosynthesis, and the most effective in blue light.

scholarly journals Soluble Cyanobacterial Carotenoprotein as a Robust Antioxidant Nanocarrier and Delivery Module

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 869
Author(s):  
Eugene G. Maksimov ◽  
Alexey V. Zamaraev ◽  
Evgenia Yu. Parshina ◽  
Yury B. Slonimskiy ◽  
Tatiana A. Slastnikova ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Protein Complexes ◽  
Neuroblastoma Cell ◽  
Spectroscopic Properties ◽  
Neuroblastoma Cell Line ◽  
Water Soluble ◽  
Modular Systems ◽  
Pigment Protein Complexes ◽  
Anabaena Sp ◽  
Pcc 7120

To counteract oxidative stress, antioxidants including carotenoids are highly promising, yet their exploitation is drastically limited by the poor bioavailability and fast photodestruction, whereas current delivery systems are far from being efficient. Here we demonstrate that the recently discovered nanometer-sized water-soluble carotenoprotein from Anabaena sp. PCC 7120 (termed AnaCTDH) transiently interacts with liposomes to efficiently extract carotenoids via carotenoid-mediated homodimerization, yielding violet–purple protein samples. We characterize the spectroscopic properties of the obtained pigment–protein complexes and the thermodynamics of liposome–protein carotenoid transfer and demonstrate the delivery of carotenoid echinenone from AnaCTDH into liposomes with an efficiency of up to 70 ± 3%. Most importantly, we show efficient carotenoid delivery to membranes of mammalian cells, which provides protection from reactive oxygen species (ROS). Incubation of neuroblastoma cell line Tet21N in the presence of 1 μM AnaCTDH binding echinenone decreased antimycin A ROS production by 25% (p < 0.05). The described carotenoprotein may be considered as part of modular systems for the targeted antioxidant delivery.

scholarly journals Insights into Solution Structures of Photosynthetic Protein Complexes from Small-Angle Scattering Methods

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 203
Author(s):  
Maksym Golub ◽  
Adrian Kölsch ◽  
Artem Feoktystov ◽  
Athina Zouni ◽  
Jörg Pieper
Keyword(s):  
Aqueous Solution ◽  
High Resolution ◽  
Photosystem I ◽  
Small Angle ◽  
Protein Complexes ◽  
Photosynthetic Pigment ◽  
Water Soluble ◽  
Model Systems ◽  
Radius Of Gyration ◽  
Pigment Protein Complexes

High-resolution structures of photosynthetic pigment–protein complexes are often determined using crystallography or cryo-electron microscopy (cryo-EM), which are restricted to the use of protein crystals or to low temperatures, respectively. However, functional studies and biotechnological applications of photosystems necessitate the use of proteins isolated in aqueous solution, so that the relevance of high-resolution structures has to be independently verified. In this regard, small-angle neutron and X-ray scattering (SANS and SAXS, respectively) can serve as the missing link because of their capability to provide structural information for proteins in aqueous solution at physiological temperatures. In the present review, we discuss the principles and prototypical applications of SANS and SAXS using the photosynthetic pigment–protein complexes phycocyanin (PC) and Photosystem I (PSI) as model systems for a water-soluble and for a membrane protein, respectively. For example, the solution structure of PSI was studied using SAXS and SANS with contrast matching. A Guinier analysis reveals that PSI in solution is virtually free of aggregation and characterized by a radius of gyration of about 75 Å. The latter value is about 10% larger than expected from the crystal structure. This is corroborated by an ab initio structure reconstitution, which also shows a slight expansion of Photosystem I in buffer solution at room temperature. In part, this may be due to conformational states accessible by thermally activated protein dynamics in solution at physiological temperatures. The size of the detergent belt is derived by comparison with SANS measurements without detergent match, revealing a monolayer of detergent molecules under proper solubilization conditions.

scholarly journals Soluble cyanobacterial carotenoprotein as a robust antioxidant nanocarrier and delivery module

2019 ◽  
Author(s):  
Eugene G. Maksimov ◽  
Alexey V. Zamaraev ◽  
Evgenia Yu. Parshina ◽  
Yury B. Slonimskiy ◽  
Tatiana A. Slastnikova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Targeted Delivery ◽  
Mammalian Cells ◽  
Protein Complexes ◽  
Natural Antioxidants ◽  
Spectroscopic Properties ◽  
Water Soluble ◽  
Modular Systems ◽  
Long Term Storage ◽  
Pigment Protein Complexes

AbstractTo counteract oxidative stress, antioxidants including carotenoids are highly promising, yet their exploitation is drastically limited by the poor bioavailability and fast photodestruction, whereas current delivery systems are far from being efficient. Here we demonstrate that the recently discovered nanometer-sized water-soluble carotenoprotein from Anabaena (termed CTDH) transiently interacts with liposomes to efficiently extract carotenoids via carotenoid-mediated homodimerization, yielding violet-purple protein samples amenable to lyophilization and long-term storage. We characterize spectroscopic properties of the pigment-protein complexes and thermodynamics of liposome-protein carotenoid transfer and demonstrate the highly efficient delivery of echinenone form CTDH into liposomes. Most importantly, we show carotenoid delivery to membranes of mammalian cells, which provides protection from reactive oxygen species. The described carotenoprotein may be considered as part of modular systems for the targeted antioxidant delivery.Significance statementCarotenoids are excellent natural antioxidants but their delivery to vulnerable cells is challenging due to their hydrophobic nature and susceptibility to degradation. Thus, systems securing antioxidant stability and facilitating targeted delivery are of great interest for the design of medical agents. In this work, we have demonstrated that soluble cyanobacterial carotenoprotein can deliver echinenone into membranes of liposomes and mammalian cells with almost 70 % efficiency, which alleviates the induced oxidative stress. Our findings warrant the robustness of the protein-based carotenoid delivery for studies of carotenoid activities and effects on cell models.

Herbicides which Interfere with the Biosynthesis of Carotenoids and Their Effect on Pigment Excitation, Chlorophyll Fluorescence and Pigment Composition of the Thylakoid Membrane

1984 ◽  
Vol 39 (5) ◽  
pp. 455-458 ◽  
Author(s):  
K. H. Grumbach
Keyword(s):  
Chlorophyll Fluorescence ◽  
Thylakoid Membrane ◽  
Protein Complexes ◽  
Red Light ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Pigment Composition ◽  
Fluorescence Emission Spectra ◽  
Characteristic Emission ◽  
Pigment Protein Complexes

Plants grown in the presence of the herbicides assayed synthesized chlorophylls during growth at low fluence rates. Subsequent irradiation with higher fluence rates of red light induced a strong chlorosis with SAN 6706 being a much stronger herbicide than J 852 or amino-triazole. All herbicides assayed also changed the content and composition of chlorophylls, carotenoids and pigment-protein-complexes of the thylakoid membrane and therefore the pigment excitation and chlorophyll fluorescence emission spectra of the plastid. With increasing herbicide toxicity the main characteristic emission bands at 690 and 730 nm disappeared and new emission bands at 715 (J 852) and 700 nm (SAN 6706) appeared. Such “artificial” membranes with a changed pigment composition were very susceptible to light. Presented data may be taken as evidence, that the lack of photoprotective cyclic carotenoids caused by the specific action of a bleaching herbicide is the primary event that may lead to a disturbed formation of the thylakoid membrane and its destruction by light and oxygen.

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