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  1. 5 Acta Biochimica Polonica

  2. 4 Current Topics in Biophysics

  3. 2 BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

  4. 2 International Agrophysics

  5. 1 Biological Letters

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  1. 3 Plonka P. M.

  2. 2 Drozd D.

  3. 2 Jezierski A.

  4. 2 Manikowski H.

  5. 2 Michalczyk D.

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  1. 3 2013

  2. 1 2009

  3. 2 2008

  4. 2 2005

  5. 1 2003

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1

Free base and metalloporphyrin radicals

100%
Manikowski H., Kubaszewski E., Lozynski M., Wroblewski M.
Current Topics in Biophysics
|
1994
|
tom 18
|
nr 2
2
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Content available

Electron paramagnetic resonance [EPR] investigations of laser induced free radicals in spring wheat grains

88%
Drozd D., Szajner H., Jezierski A.
International Agrophysics
|
1999
|
tom 13
|
nr 3
3

Triplet state of bacteriochlorophyll in reaction center of photosynthetic bacteria

75%
Manikowski H., Proskryakov I. I.
Current Topics in Biophysics
|
1992
|
tom 16
|
nr 2
4

Mitochondria recycle nitrite back to the bioregulator nitric monoxide

75%
Nohl H., Staniek K., Sobhian B., Bahrami S., Redl H., Kozlov A. V.
Acta Biochimica Polonica
|
2000
|
tom 47
|
nr 4
Nitric monoxide (NO) exerts a great variety of physiological functions. L-Arginine supplies amino groups which are transformed to NO in various NO-synthase-active isoenzyme complexes. NO-synthesis is stimulated under various conditions increasing the tissue of stable NO-metabolites. The major oxidation product found is nitrite. Elevated nitrite levels were reported to exist in a variety of diseases including HIV, reperfusion injury and hypovolemic shock. Denitrifying bacteria such as Paracoccus denitrificans have a membrane bound set of cytochromes (cyt cd1, cyt bc) which were shown to be involved in nitrite reduction activities. Mammalian mitochondria have similar cytochromes which form part of the respiratory chain. Like in bacteria quinols are used as reductants of these types of cytochromes. The observation of one-e- divergence from this redox-couple to external dioxygen made us to study whether this site of the respiratory chain may also recycle nitrite back to its bioactive form NO. Thus, the aim of the present study was therefore to confirm the existence of a reductive pathway which reestablishes the existence of the bioregulator NO from its main metabolite NO2-. Our results show that respiring mitochondria readily reduce added nitrite to NO which was made visible by nitrosylation of deoxyhemoglobin. The adduct gives characteristic triplet-ESR-signals. Using inhibitors of the respiratory chain for chemical sequestration of respiratory segments we were able to identify the site where nitrite is reduced. The results confirm the ubiquinone/cyt bc1 couple as the reductant site where nitrite is recycled. The high affinity of NO to the heme-iron of cytochrome oxidase will result in an impairment of mitochondrial energy-production. "Nitrite tolerance" of angina pectoris patients using NO-donors may be explained in that way.
5

Probing iso-1-cytochrome c structure by site-directed spin labeling and electron paramagnetic resonance techniques

75%
Pyka J., Osyczka A., Turyna B., Blicharski W., Froncisz W.
Acta Biochimica Polonica
|
1999
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tom 46
|
nr 4
A cysteine-specific methanethiosulfonate spin label was introduced into yeast iso-1-cytochrome c at three different positions. The modified forms of cytochrome c included: the wild-type protein labeled at naturally occurring C102, and two mutated proteins, S47C and L85C, labeled at positions 47 and 85, respectively (both S47C and L85C derived from the protein in which C102 had been replaced by threonine). All three spin-labeled protein derivatives were characterized using electron paramagnetic resonance (EPR) techniques. The continuous wave (CW) EPR spectrum of spin label attached to L85C differed from those recorded for spin label attached to C102 or S47C, indicating that spin label at position 85 was more immobilized and exhibited more complex tumbling than spin label at two other positions. The temperature dependence of the CW EPR spectra and CW EPR power saturation revealed further differences of spin-labeled L85C. The results were discussed in terms of application of the site-directed spin labeling technique in probing the local dynamic structure of iso-1-cytochrome c.
6

Sclerotia of the acellular [true] slime mould Fuligo septica as a model to study melanization and anabiosis

63%
Krzywda A., Petelenz E., Michalczyk D., Plonka P. M.
Cellular and Molecular Biology Letters
|
2008
|
tom 13
|
nr 1
130-143
Acellular (true) slime moulds (Myxomycetes) are capable of a transition to the stage of sclerotium — a dormant form of plasmodium produced under unfavourable environmental conditions. In this study, sclerotia of Fuligo septica were analyzed by means of electron paramagnetic resonance (EPR) spectroscopy. The moulds were cultivated in vitro on filter paper, fed with oat flour, and kept until the plasmodia began to produce sclerotia. The obtained sclerotia differed in colour from yellow through orange to dark-brown. The EPR spectra revealed a free radical, melanin-like signal correlated with the depth of the colour; it was strongest in the dark sclerotia. Sclerotization only took place when the plasmodia were starved and very slowly dried. Only the yellow sclerotia were able to regenerate into viable plasmodia. This suggests that myxomycete cytoplasm dehydration is an active process regulated metabolically. Plasmodial sclerotization may therefore serve as a convenient model system to study the regulation of cytoplasmatic water balance, and sclerotia as a convenient material for EPR measurements, combining the quality of plasmodia with the technical simplicity of the measurements characteristic of dry spores. Darkening of the sclerotia is most probably a pathological phenomenon connected with the impairment of water balance during sclerotization.
7

Badania antyoksydacyjnych wlasciwosci win owocowych i gronowych metoda EPR

63%
Wasek M., Wawer I.
Przemysł Fermentacyjny i Owocowo-Warzywny
|
2002
|
tom 46
|
nr 01
22-23
Metodą elektronowego rezonansu paramagnetycznego (EPR) zbadano zdolność wymiatania rodnika DPPH przez czerwone i białe wina gronowe oraz wina owocowe. Bardzo silne właściwości anty oksydacyjne, porównywalne z właściwościami czerwonych win gronowych, wykazały wina z owoców aronii i wiśni.
8
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EPR-spin labelling measurements of thylakoid membrane fluidity during barely leaf senescence

63%
Jajic I., Sarna T., Wisniewska A., Strzalka K.
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
|
2013
|
tom 94
|
nr 2
9
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Singlet oxygen scavenging by tocopherol and plastochromanol under photooxidative stress in Arabidopsis thaliana

63%
Yadav D., Rastogi A., Szymanska R., Kruk J., Sedlarova M., Pospisil P.
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
|
2013
|
tom 94
|
nr 2
10

In vitro effects of ozone on human erythrocyte membranes: An EPR study

63%
Gornicki A., Gutsze A.
Acta Biochimica Polonica
|
2000
|
tom 47
|
nr 4
The effects of ozone at different concentrations (10, 30, 45 g/m3) on fluidity and thermotropic properties of erythrocyte membranes were investigated by EPR using two spin probes: 5-doxylstearic acid (5-DSA) and 16-doxylstearic acid (16-DSA). The effect of ozone on the erythrocyte membrane fluidity was a dose-dependent process. The ozone at concentration of 10 g/m3 caused rigidization of the membrane while at concentration of 45 g/m3 increased fluidity both on the surface and in the deeper hydrocarbon region of the membrane. Temperature transitions close to the polar heads region (monitored by 5-DSA) were not sensitive to an increase in ozone concentration. In the case of 16-DSA, low temperature thermotropic transition (around 20°C) gradually decreased with the increase of ozone concentration. High temperature transition (around 40°C) significantly differed at the ozone concentration of 10 g/m3 and 45 g/m3, being higher and lower, respectively, as compared to untreated cells. For the ozone concentration of 45 g/m3 the disappearance of the low temperature break and the appearance of two breaks at 37°C and 16°C were observed.
11

Free radical scavenging activity for infusions of 30 medicinal plants detected with electron paramagnetic resonance

63%
Jeziorek M., Wasek M.
Herba Polonica
|
2008
|
tom 54
|
nr 1
DPPH radical scavenging activity for thirty medicinal plant infusions was investigated with a use of Electron Paramagnetic Resonance. Infusions were prepared in similar way in which herbs or herbal teas are prepared directly for human consumption. Samples were obtained mostly from popular and easy available medicinal plants, used as single herbs or in herbal mixtures. The total flavonoid content for fifteen selected plants was measured using modified Christ-Müller method. The best DPPH radical scavenging activity (more than 50% of DPPH radical reduced in examined sample after 1 h) was obtained for Melissae folium (87%), Sambuci flos (81%), Ulmariae flos (79%), Hyperici herba (67%) and Arnicae anthodium (66%). Green tea confirmed to be strong DPPH scavenger among examined plants (65%). The highest flavonoid amounts were discovered for Ulmariae flos (1.5%), Hyperici herba (1.2%), Betulae folium (0.9%). There was no correlation between DPPH scavenging activity and the total content of flavonoids in examined plan material.
12

Splenic aumelanin differs from hair eumelanin in C57BL-6 mice

63%
Plonka P. M., Michalczyk D., Popik M., Handjiski B., Slominski A., Paus R.
Acta Biochimica Polonica
|
2005
|
tom 52
|
nr 2
The presence of melanin in spleens of black C57BL/6 mice has been known for long. Although its origin and biological functions are still obscure, the relation of splenic melanin to the hair follicle and skin pigmentation was suggested. Here, we demonstrated using for the first time electron paramagnetic resonance spectroscopy that black-spotted C57BL/6 spleens contain eumelanin. Its presence here is a “yes or no” phenomenon, as even in the groups which revealed the highest percentage of spots single organs completely devoid of the pigment were found. Percentage of the spotted spleens decreased, however, with the progress of telogen after spontaneously-induced hair growth. The paramagnetic properties of the spleen eumelanin differed from the hair shaft or anagen VI skin melanin. The splenic melanin revealed narrower signal, and its microwave power saturability betrayed more heterogenous population of paramagnetic centres than in the skin or hair shaft pigment. Interestingly, the pigment of dry hair shafts and of the wet tissue of depilated anagen VI skin revealed almost identical properties. The properties of splenic melanin better resembled the synthetic dopa melanin (water suspension, and to a lesser degree – powder sample) than the skin/hair melanin. All these findings may indicate a limited degradation of splenic melanin as compared to the skin/hair pigment. The splenic eumelanin may at least in part originate from the skin melanin phagocyted in catagen by the Langerhans cells or macrophages and transported to the organ.
13
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Concentration of free radicals in faba bean seeds after the pre-sowing treatment of the seeds with laser light

63%
Podlesny J., Misiak L., Koper R.
International Agrophysics
|
2001
|
tom 15
|
nr 3
14

Free-radical method for L-ascorbic acid determination in tissues of experimental animals

63%
Gonet B.
Current Topics in Biophysics
|
1994
|
tom 18
|
nr 2
15

Controlled cholesterol efflux from the aortic smooth muscle cells triggers microheterogeneity of plasma membrane lipids and induces modification of the mitochondrial topology

51%
Tukaj C., Syta-Ksiazek E., Zauszkiewicz A., Drozd K., Figarski A., Spodnik J. H., Wozniak M.
Folia Morphologica
|
2009
|
tom 68
|
nr 4
244-246
It is generally accepted that phospholipids of plasma membrane display lateral segregation into small microdomains commonly known as lipid rafts. Such lateral lipid organization is under the control of cholesterol. Cholesterol depletion evolved by methyl-β-cyclodextrin (MCD) has been found to induce further marked perturbation in lateral lipid organization, evidenced in the high field part of electron paramagnetic resonance spectra of plasma membranes labelled with a spectroscopic probe, namely 5-doxyl-stearic acid (5DOXS). Such perturbation of surface lipid topo-logy has been found to induce distinct changes in the mitochondrial morpho-logy, i.e. switch from filamentous form into small granular form. (Folia Morphol 2009; 68, 4: 244–246)
16

Zastosowanie elektronowego rezonansu paramagnetyczego [EPR] do oceny wplywu promieniowania laserowego na ziarniaki pszenicy jarej

51%
Drozd D., Szajsner H., Jezierski A.
Biuletyn Instytutu Hodowli i Aklimatyzacji Roślin
|
1997
|
nr 204
181-186
17
Content available remote

Salt is an oxidative stressor for gastric epithelial cells

51%
Tamura M., Matsui H., Nagano Y. N., Kaneko T., Indo H. P., Majima H. J., Hyodo I.
Journal of Physiology and Pharmacology
|
2013
|
tom 64
|
nr 1
18

Characterization of germinating lupine seeds by NMR imaging and EPR spectroscopy

51%
Garnczarska M., Wojtyla L., Bednarski W., Zalewski T., Jurga S.
Biological Letters
|
2005
|
tom 42
|
nr 2 Spec.Vol.
19

EPR imaging of free radicals in the perfused heart

51%
Kuppusamy P., Zweier J. L.
Current Topics in Biophysics
|
1994
|
tom 18
|
nr 1
20

Kinetics of increased generation of NO in endotoxaemic rats as measured by EPR

51%
Plonka P. M., Chlopicki S., Wisniewska M., Plonka B. K.
Acta Biochimica Polonica
|
2003
|
tom 50
|
nr 3
Ferrous-diethyldithiocarbamate (Fe(DETC)2) chelate is a lipophilic spin trap devel­oped for NO detection by electron paramagnetic resonance (EPR) spectroscopy. Using this spin trap we investigated the kinetics of NO production in endotoxaemia in rats induced by lipopolysaccharide (Escherichia coli, 10 mg/kg). The NO-Fe(DE- TC)2 complex was found to give a characteristic EPR signal, and the amplitude of the 3rd (high-field) component of its hyperfine splitting was used to monitor the level of NO. We found that in blood, kindey, liver, heart and lung NO production starts to in­crease as early as 2 h after LPS injection, reaches the maximum 6 h after LPS injec­tion and then returns to basal level within further 12-18 h. Interestingly, in the eye bulb the maximum of NO production was detected 12 h after LPS, and the signal was still pronounced 24 h after LPS. In brief, the highly lipophilic exogenous spin trap, Fe(DETC)2 is well suited for assessment of NO production in endotoxaemia. We dem­onstrated that the kinetics of increased production of NO in endotoxaemic organs, with the notable exception of the eye, do not follow the known pattern of NOS-2 induc­tion under those conditions. Accordingly, only in early endotoxaemia a high level of NO is detected, while in late endotoxaemia NO detectability is diminished most probably due to concomitant oxidant stress.
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