Wyniki wyszukiwania

1

Purification of biologically active violaxanthin de-epoxidase from Escherichia coli

100%

Olchawa-Pajor M., Latowski D., Kuczynska P., Bojko M., Strzalka K.

Acta Biologica Cracoviensia. Series Botanica. Supplement

|

2011

|

tom 53

|

nr 1

2

Heavy metal-induced oxidative damage, defense reactions, and detoxification mechanisms in plants

86%

Sytar O., Latowski D., Kumar A., Kuczynska P., Strzalka K., Prasad M. N. V.

Acta Physiologiae Plantarum

|

2013

|

tom 35

|

nr 04

Heavy metal (HMs) contamination is widespread globally due to anthropogenic, technogenic, and geogenic activities. The HMs exposure could lead to multiple toxic effects in plants by inducing reactive oxygen species (ROS), which inhibit most cellular processes at various levels of metabolism. ROS being highly unstable could play dual role (1) damaging cellular components and (2) act as an important secondary messenger for inducing plant defense system. Cells are equipped with enzymatic and non-enzymatic defense mechanisms to counteract this damage. Some are constitutive and others that are activated only when a stress-specific signal is perceived. Enzymatic scavengers of ROS include superoxide dismutase, catalase, glutathione reductase, and peroxidase, while nonenzymatic antioxidants are glutathione, ascorbic acid, a-tocopherol, flavonoids, anthocyanins, carotenoids, and organic acids. The intracellular and extracellular chelation mechanisms of HMs are associated with organic acids such as citric, malic and oxalic acid, etc. The important mechanism of detoxification includes metal complexation with glutathione, amino acids, synthesis of phytochelatins and sequestration into the vacuoles. Excessive stresses induce a cascade, MAPK (mitogen-activated protein kinase) pathway and synthesis of metal-detoxifying ligands. Metal detoxification through MAPK cascade and synthesis of metal-detoxifying ligands will be of considerable interest in the field of plant biotechnology. Further, the photoprotective roles of pigments of xanthophylls cycle under HMs stress were also discussed.

3

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

The effect of temperature on growth of Thalassiosira pseudonana in vitro system

86%

Bojko M., Wanda P., Latowski D., Kuczynska P., Olchawa-Pajor M., Strzalka K.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2013

|

tom 94

|

nr 3

4

Zeaxanthin epoxidation - an in vitro approach

86%

Kuczynska P., Latowski D., Olchawa-Pajor M., Jahns P., Gruszecki W. I., Strzalka K.

Acta Biochimica Polonica

|

2012

|

tom 59

|

nr 1

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.

5

Expression of three diadinoxanthin de-epoxidase genes of Phaeodacylum tricornutum in Escherichia coli Origami b and BL21 strain

86%

Bojko M., Olchawa-Pajor M., Tuleja U., Kuczynska P., Strzalka W., Latowski D., Strzalka K.

Acta Biochimica Polonica

|

2013

|

tom 60

|

nr 4

In the diadinoxanthin cycle the epoxy group is removed from diadinoxanthin and diatoxanthin is created. This conversion takes place e.g. in diatoms with the involvement of the enzyme diadinoxanthin de-epoxidase. In one of the diatom species, Phaeodactylum tricornutum (CCAP 1055/1 strain with genome sequenced) three de-epoxidase genes (PtVDE, PtVDL1, PtVDL2) have been identified, but only one of them (PtVDE) corresponds to violaxanthin de-epoxidase, an enzyme which is commonly found in higher plants. In these studies, the expression of two de-epoxidase genes of another Phaeodactylum tricornutum strain (UTEX 646), which is commonly used in diatom studies, were obtained in Origami b and BL21 E. coli strains. The molecular masses of the mature proteins are about 49 kDa and 60 kDa, respectively, for VDE and VDL2. Both enzymes are active with violaxanthin as a substrate.

6

Determination of epoxides in Escherichia coli expressing recombinant zeaxanthin epoxidase

86%

Kuczynska P., Leskiewicz S., Strzalka W., Olchawa-Pajor M., Bojko M., Latowski D., Strzalka K.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2013

|

tom 94

|

nr 3

7

Zeaxanthin epoxidation – an in vitro approach

86%

Kuczynska P., Latowski D., Niczyporuk S., Olchowa-Pajor M., Jahns P., Gruszecki W. I., Strzalka K.

Acta Biologica Cracoviensia. Series Botanica. Supplement

|

2011

|

tom 53

|

nr 1

8

Temperature effect on growth, and selected parameters of Phaeodactylum tricornutum in batch cultures

72%

Bojko M., Brzostowska K., Kuczynska P., Latowski D., Olchawa-Pajor M., Krzeszowiec W., Waloszek A., Strzalka K.

Acta Biochimica Polonica

|

2013

|

tom 60

|

nr 4

The effect of optimal and stress temperatures on the growth kinetics of the Phaeodactylum tricornutum CCAP/1055/1 strain (a model diatom with a known genome sequence) in batch cultures was examined. The analysis of the obtained results showed two phases of culture growth. There were significant positive correlations between OD increase of chlorophyll a chlorophyll c and protein concentration at different temperatures. The Fv/Fm parameter achieved a maximum level on the 6th or 7th day and then decreased to the values registered on the first day of observation. Genetic material undergoes gradual degradation 10 days after inoculation. The size of the cells was invariable.

9

Effect of different variants of pre-slaughter transport on body weight loss and meat quality in broiler chickens

72%

Sowinska J., Wojcik A., Pomianowski J. F., Chorazy L., Mituniewicz T., Witkowska D., Piotrowska J., Kwiatkowska-Stenzel A., Czaplinska B., Kuczynska P.

Medycyna Weterynaryjna

|

2013

|

tom 69

|

nr 07

The aim of this study was to determine the effect of different variants of pre-slaughter procedures in the winter on body weight loss in broiler chickens, and on the proximate chemical composition and physicochemical properties of meat. At the completion of a six-week rearing period, 240 ROSS 308 chickens were subjected to the following variants of pre-slaughter transport: no transport (N-T), transport to a distance of 100 km (T-100), 200 km (T-200) and 300 km (T-300). The acidity of breast muscles (pH₁₅ and pH₂₄) was measured with a portable meat pH-meter, HI 99163 (Hanna Instruments, Germany) supplied with an FC 232D electrode. Meat color (15 minutes and 24 hours post mortem) was determined with the use of a Minolta CR-400 chroma meter (Japan), in the CIE L* a* b* system. Water-holding capacity (24 hours post mortem) was determined as drip loss. The content of water, protein and fat in meat was determined using an InfraLab 710 near-infrared analyzer (NDC Infrared Engineering, UK). The results of the conducted study showed that the elongation of transport length for a distance of 200 km and 300 km influenced the increase of broiler weight loss. Significantly higher (P = 0.01) weight loss was observed after transport to a distance of 200 and 300 km, compared to a group of chickens from group T-100 (respectively 2.65%, 2.36% and 1.41%). It cannot be stated clearly that variants of transportation have contributed to the deterioration of the quality of the meat acquired. The longest transport distance resulted in a faster rate of the pectoral muscle glycolysis in group T-300 (0.69 units) compared to the other groups (0.60-0.62 units). The broiler meat from group T-300, as compared to the other groups, was also characterized by a significantly higher surface of drip loss and the parameters L * 24 and b * 24, which reflected in its significantly lighter color and lower water-holding capacity. However, the final pH values were similar in all groups and did not show any meat defects. In addition, the basic chemical composition of chicken muscles showed their good nutritional value.

Ograniczanie wyników

Purification of biologically active violaxanthin de-epoxidase from Escherichia coli

Heavy metal-induced oxidative damage, defense reactions, and detoxification mechanisms in plants

The effect of temperature on growth of Thalassiosira pseudonana in vitro system

Zeaxanthin epoxidation - an in vitro approach

Expression of three diadinoxanthin de-epoxidase genes of Phaeodacylum tricornutum in Escherichia coli Origami b and BL21 strain

Determination of epoxides in Escherichia coli expressing recombinant zeaxanthin epoxidase

Zeaxanthin epoxidation – an in vitro approach

Temperature effect on growth, and selected parameters of Phaeodactylum tricornutum in batch cultures

Effect of different variants of pre-slaughter transport on body weight loss and meat quality in broiler chickens