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    Wyświetlanie 1-8 z 8
    Tytuł:
    Zeaxanthin epoxidation - an in vitro approach
    Autorzy:
    Kuczyńska, Paulina
    Latowski, Dariusz
    Niczyporuk, Sylvia
    Olchawa-Pajor, Monika
    Jahns, Peter
    Gruszecki, Wiesław
    Strzałka, Kazimierz
    Powiązania:
    https://bibliotekanauki.pl/articles/1039789.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    Arabidopsis thaliana mutants npq1
    model system
    npq2
    xanthophyll cycle
    zeaxanthin epoxidation
    Opis:
    Zeaxanthin epoxidase (ZE) is an enzyme operating in the violaxanthin cycle, which is involved in photoprotective mechanisms. In this work model systems to study zeaxanthin (Zx) epoxidation were developed. Two assay systems are presented in which epoxidation of Zx was observed. In these assays two mutants of Arabidopsis thaliana which have active only one of the two xanthophyll cycle enzymes were used. The npq1 mutant possesses an active ZE and is thus able to convert Zx to violaxanthin (Vx) but the violaxanthin de-epoxidase (VDE) is inactive, so that Vx cannot be converted to Zx. The other mutant, npq2, possesses an active VDE and can convert exogenous Vx to Zx under strong light conditions but reverse reaction is not possible. The first assay containing thylakoids from npq1 and npq2 mutants of A. thaliana gave positive results and high efficiency of epoxidation reaction was observed. The amount of Zx was reduced by 25%. To optimize high efficiency of epoxidation reaction additional factors facilitating both fusion of the two types of thylakoids and incorporation of Zx to their membranes were also studied. The second kind of assay contained npq1 mutant thylakoids of A. thaliana supplemented with exogenous Zx and monogalactosyldiacylglycerol (MGDG). Experiments with different proportions of Zx and MGDG showed that their optimal ratio is 1:60. In such system, due to epoxidation, the amount of Zx was reduced by 38% of its initial level. The in vitro systems of Zx epoxidation described in this paper enable analysis some properties of the ZE without necessity of its isolation.
    Źródło:
    Acta Biochimica Polonica; 2012, 59, 1; 105-107
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Determination of epoxides in Escherichia coli expressing recombinant zeaxanthin epoxidase
    Autorzy:
    Kuczynska, P.
    Leskiewicz, S.
    Strzalka, W.
    Olchawa-Pajor, M.
    Bojko, M.
    Latowski, D.
    Strzalka, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/81277.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    conference
    zeaxanthin epoxidase
    overexpression
    violaxanthin
    antheraxanthin
    Escherichia coli
    spectrofluorometry
    Źródło:
    BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 3
    0860-7796
    Pojawia się w:
    BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Overexpression of zeaxanthin epoxidase gene from Medicago sativa enhances the tolerance to low light in transgenic tobacco
    Autorzy:
    Cao, Yuman
    Zhang, Zhiqiang
    Zhang, Tong
    You, Zhang
    Geng, Jincai
    Wang, Yafang
    Hu, Tianming
    Yang, Peizhi
    Powiązania:
    https://bibliotekanauki.pl/articles/1038375.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    Medicago sativa
    low-light tolerance
    zeaxanthin epoxidase
    overexpression
    Opis:
    Zeaxanthin epoxidase (ZEP) plays an important role in xanthophyll cycle which is a process closely related to photosynthesis. However, an impact of ZEP on low-light stress has not been studied. In this study, the functions of an alfalfa (Medicago sativa) zeaxanthin epoxidase gene, MsZEP, in response to low-light stress were investigated by heterologous expression in tobacco (Nicotiana tabacum). Under normal light conditions, the measured parameters were not significantly different between transgenic and wild-type (WT) plants except for non-photochemical quenching value and chlorophyll a content. However, the differences were detected under low-light stress. We found that MsZEP-overexpression tobacco grew faster than WT (p≤0.05). The leaf fresh weight and leaf area of transgenic plants were significantly higher, and the number of stomata was greater in MsZEP-overexpression tobacco. As for photosynthetic characteristics, quantum yield of PSII (ΦPSII) and maximal photochemical efficiency of PSII (Fv/Fm) were not significantly different, whereas non-photochemical quenching (NPQ), net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of MsZEP-overexpression tobacco were significantly higher than in WT plants. However, no significant difference was detected between the two types of tobacco in chlorophyll and carotenoids content. In conclusion, MsZEP can improve the ability of tobacco to withstand low-light stress, which might be due to its stronger photosynthetic activity and the improvement of stomatal density under low light.
    Źródło:
    Acta Biochimica Polonica; 2018, 65, 3; 431-435
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evaluation of Potato Cultivars and Breeding Lines for Carotenoids Content in Tubers
    Autorzy:
    Milczarek, Dorota
    Tatarowska, Beata
    Powiązania:
    https://bibliotekanauki.pl/articles/2199678.pdf
    Data publikacji:
    2017-06-20
    Wydawca:
    Instytut Hodowli i Aklimatyzacji Roślin
    Tematy:
    analysis
    extraction
    lutein
    total carotenoids (TC)
    zeaxanthin
    Opis:
    The potato is one of the most common elements of everyday human diet due to its high nutritional and culinary value. Potato tubers provide mainly energy in the form of carbohydrates and also some other nu-trients, which include carotenoids as compounds linked to oxidation-preventing mechanisms. The main assi-milable carotenoids present in cultivated potato are lutein and zeaxanthin. Potato cultivars rich in carotenoids are a subject of increasing consideration in breeding for improvement of the nutritional quality of tubers. The paper describes the spectrophotometric method of evaluation of total and individual carotenoids content in potato tubers.
    Źródło:
    Plant Breeding and Seed Science; 2017, 75; 11-16
    1429-3862
    2083-599X
    Pojawia się w:
    Plant Breeding and Seed Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Occurrence of neoxanthin and lutein epoxide cycle in parasitic Cuscuta species
    Autorzy:
    Kruk, Jerzy
    Szymańska, Renata
    Powiązania:
    https://bibliotekanauki.pl/articles/1040836.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    violaxanthin de-epoxidase
    Cuscuta
    xanthophyll cycle
    zeaxanthin epoxidase
    neoxanthin
    lutein epoxide cycle
    Opis:
    In the present study, xanthophyll composition of eight parasitic Cuscuta species under different light conditions was investigated. Neoxanthin was not detected in four of the eight species examined, while in others it occurred at the level of several percent of total xanthophylls. In C. gronovii and C. lupuliformis it was additionally found that the neoxanthin content was considerably stimulated by strong light. In dark-adapted plants, lutein epoxide level amounted to 10-22% of total xanthophylls in only three species, the highest being for C. lupuliformis, while in others it was below 3%, indicating that the lutein epoxide cycle is limited to only certain Cuscuta species. The obtained data also indicate that the presence of the lutein epoxide cycle and of neoxanthin is independent and variable among the Cuscuta species. The xanthophyll cycle carotenoids violaxanthin, antheraxanthin and zeaxanthin were identified in all the examined species and occurred at the level found in other higher plants. The xanthophyll and lutein epoxide cycle pigments showed typical response to high light stress. The obtained results also suggest that the ability of higher plants to synthesize lutein epoxide probably does not depend on the substrate specificity of zeaxanthin epoxidase but on the availability of lutein for the enzyme.
    Źródło:
    Acta Biochimica Polonica; 2008, 55, 1; 183-190
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Can macular xanthophylls replace cholesterol in formation of the liquid-ordered phase in lipid-bilayer membranes?
    Autorzy:
    Subczynski, Witold
    Wisniewska-Becker, Anna
    Widomska, Justyna
    Powiązania:
    https://bibliotekanauki.pl/articles/1039790.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    lutein
    spin-labeling
    zeaxanthin
    liquid-ordered phase
    EPR
    Opis:
    Lateral organization of membranes made from binary mixtures of dimyristoylphosphatidylcholine (DMPC) or dipalmitoylphosphatidylcholine (DPPC) and macular xanthophylls (lutein or zeaxanthin) was investigated using the saturation-recovery (SR) EPR spin-labeling discrimination by oxygen transport (DOT) method in which the bimolecular collision rate of molecular oxygen with the nitroxide spin label is measured. This work was undertaken to examine whether or not lutein and zeaxanthin, macular xanthophylls that parallel cholesterol in its function as a regulator of both membrane fluidity and hydrophobicity, can parallel other structural functions of cholesterol, including formation of the liquid-ordered phase in membranes. The DOT method permits discrimination of different membrane phases when the collision rates (oxygen transport parameter) differ in these phases. Additionally, membrane phases can be characterized by the oxygen transport parameter in situ without the need for separation, which provides information about the dynamics of each phase. In gel-phase membranes, two coexisting phases were discriminated in the presence of macular xanthophylls - namely, the liquid-ordered-like and solid-ordered-like phases. However, in fluid-phase membranes, xanthophylls only induce the solitary liquid-ordered-like phase, while at similar concentrations, cholesterol induces coexisting liquid-ordered and liquid-disordered phases. No significant differences between the effects of lutein and zeaxanthin were found.
    Źródło:
    Acta Biochimica Polonica; 2012, 59, 1; 109-114
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Synthesis of highly 13C enriched carotenoids: access to carotenoids enriched with 13C at any position and combination of positions
    Autorzy:
    Lugtenburg, Johan
    Dawadi, Prativa
    Powiązania:
    https://bibliotekanauki.pl/articles/1039761.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    astaxanthin
    β-carotene
    zeaxanthin
    canthaxanthin
    spheroidene
    Opis:
    Carotenoids and their metabolites are essential factors for the maintenance of important life processes such as photosynthesis. Animals cannot synthesize carotenoids de novo, they must obtain them via their food. In order to make intensive animal husbandry possible and maintain human and animal health synthetic nature identical carotenoids are presently commercially available at the multi-tonnes scale per year. Synthetically accessible 13C enriched carotenoids are essential to apply isotope sensitive techniques to obtain information at the atomic level without perturbation about the role of carotenoids in photosynthesis, nutrition, vision, animal development, etc. Simple highly 13C enriched C1, C2 and C3 building blocks are commercially available via 99% 13CO. The synthetic routes for the preparation of the 13C enriched building blocks starting from the commercially available systems are discussed first. Then, how these building blocks are used for the synthesis of the various 13C enriched carotenoids and apocarotenoids are reviewed next. The synthetic Schemes that resulted in 13C enriched β-carotene, spheroidene, β-cryptoxanthin, canthaxanthin, astaxanthin, (3R,3'R)-zeaxanthin and (3R,3'R,6'R)-lutein are described. The Schemes that are reviewed can also be used to synthetically access any carotenoid and apocarotenoid in any 13C isotopically enriched form up to the unitarily enriched form.
    Źródło:
    Acta Biochimica Polonica; 2012, 59, 1; 11-16
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Lutein and zeaxanthin – radio- and chemoprotective properties. Mechanism and possible use
    Autorzy:
    Fiedorowicz, J.
    Dobrzyńska, M.M.
    Powiązania:
    https://bibliotekanauki.pl/articles/28765163.pdf
    Data publikacji:
    2023
    Wydawca:
    Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
    Opis:
    Lutein and zeaxanthin are naturally occurring xanthophylls, mainly present in green, leafy vegetables and egg’s yolk. Their presence is connected with blue spectrum light absorbance, including UV. This property, and fact, that these xanthophylls are accumulated by human eye’s macula, leads to eye’s protective functions of them including protection from age-related macular degeneration (AMD). Also, antioxidative features of lutein and zeaxanthin are boosting overall health of human body. Numerous studies proves anti-inflammatory and protective attributes of these compounds, based on many, different mechanisms. One of them is regulating redox potential in cells, and impact on expression of linked genes. In preventing of eye diseases, an important gene that is regulated by lutein and zeaxanthin is the Nrf2 gene, whose increased activity leads to optimizing the cellular response to reactive oxygen species (ROS) and preventing related diseases. Other research confirms antiproliferative properties of mentioned compounds in case of certain human cancer cell lines. There are e.g.: HepG2 (hepatitis cancer), MCF-7 (breast cancer), which treated in vitro with lutein solution showed reduction of cell growth. Lutein alone, during in vivo studies conducted on mice, exhibited also radioprotective properties, positively affecting the vitality of animals. Lutein provides also increasing of tolerance to UV radiation, reducing inflammatory processes in the skin and preventing oncogenesis. Low intake of lutein and zeaxanthin, associated with “western diet”, rich in simple carbohydrates and processed food, common in developed countries, including Poland, is linked with diabetes and obesity incidence. Assuming, lutein and zeaxanthin significantly affect the well-being of the human body, and their appropriate amount in diet can help reduce risk of many diseases. For supplementation, the optimized dosage of these xanthophylls includes doses of 10 mg for lutein and 2 mg for zeaxanthin, and it is recommended to consume along with fats or meals rich in fats.
    Źródło:
    Roczniki Państwowego Zakładu Higieny; 2023, 74, 3; 257-264
    0035-7715
    Pojawia się w:
    Roczniki Państwowego Zakładu Higieny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-8 z 8

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