Kvetoslava Burda - Academia.edu (original) (raw)

Papers by Kvetoslava Burda

Acta Physica Polonica A, May 1, 2003

A p p l icati on of M ossb au er Sp ectros cop y in Stu d y of Sele cte d B io ch em ical Pro ces... more A p p l icati on of M ossb au er Sp ectros cop y in Stu d y of Sele cte d B io ch em ical Pro cesses K. B ur d a a and J. St an ek b; Ê a H. N i ewo dni czan ski Ins ti t ute of Nucl ear P hysi cs R adzi kowski ego 152, 31-342 Kra k §w, Po l and b M. Smol uchowski Insti tute of Physi cs, Jagi ell oni an Uni versi ty Reym on ta 4, 30-059 Kra k § w, Po l and (Recei ved J anua r y 15, 2003) T he 57 F e; 11 9 Sn; 129 I; and 151 Eu M ossbauer spectroscop y , scannin g force microscopy , and optica l Ûuorescence metho d w ere appli ed to study biologi cal systems starting from porphyrins, through cyto chromes and cell membranes until such a comple x system as photosystem I I. I n Fe-p orphyrin aggregates iron atoms are able to trap an electron exhibiti ng the mixed v alence F e 3 + À Fe 2+ relaxation pro cess. I n ironcyto chrome c the presence of tw o di˜erent Fe 3+ states are indicated , w hile in tincyto chrome Sn appears in Sn 4+ and Sn 2+ states. From the temp erature dep endence of the mean square displace ment of the resonance nuclei and from the di˜usi onal broadening of the M ossbauer line it w as possibl e to separate the vibrati onal , fast collecti ve and slow collectiv e motions in tinp orphyrin and in iron-and tin-cyto chrome c. T he electronic state of iodin e in oleic acid, the main constituent of cellular membranes, w as determined. T he molecular mechanism of triphenylti n interaction with membrane of red blo od cells has been suggested and the mo del of haemolysi s has been prop osed. In photosystem I I, Eu ions replacing calcium show ed Eu 3+ to Eu 2+ transition after illumi nation w ith light, w hich p oints out the p ossible role of C a 2+ ions in electron transf er in the pro cess of photosynthetic w ater splitting pro cess.

Zeitschrift für Naturforschung C, Jun 1, 1996

We use the Markow chain theory to analyze the oscillation pattern of oxygen evolution during wate... more We use the Markow chain theory to analyze the oscillation pattern of oxygen evolution during water oxidation in photosystem II under short saturating light flashes. We propose a method based on the standard least square deviation (test x 2) to determine the number of 5-states in the Kok model. As pointed out by Burda et al. (1995) this information is amongst others important for the interpretation of the role of calcium for oxygen evolution. A specific mathematical representation for a situation when the S4 state is longer living than generally assumed is introduced which requires an explicit extension of the Kok model to five states. The higher stability is modelled by introducing additional decay channels, e.g. a nonvanishing probability for the transition of S3 to the 5() state and a further transition probability for the transition from S3 to 5 4. Our analysis is extended to the case of damped oscillations of oxygen evolution caused, for example, by the lack of electron acceptor or the short life time of photosystem II particles.

Acta Biochimica Polonica, Nov 8, 2011

We studied the influence of low doses of γ radiation (from 0.04 to 1.8 mGy) on the stability of h... more We studied the influence of low doses of γ radiation (from 0.04 to 1.8 mGy) on the stability of human red blood cells (RBC) from healthy donors and diabetic patients using absorption spectroscopy. Because of the alteration of many enzymatic pathways in diabetic RBCs resulting in strong modification of the lipid and protein membrane components one could expect that the ionizing γ-radiation should influence the stability of the healthy and diabetic cells in a different way. Indeed, distinct discontinuities and monotonic changes of hemolysis detected in the healthy and diabetic RBCs suggest that various enzymatic and chemical processes are activated in these membranes by γ radiation. Mössbauer measurements showed that only the highest applied dose of γ radiation caused modification of hemoglobin in both types of RBCs.

Journal of Hypertension, Jun 1, 2011

Microscopy Research and Technique, Aug 3, 2023

In this work, a new approach to construct self‐assembled hybrid systems based on natural PSII‐enr... more In this work, a new approach to construct self‐assembled hybrid systems based on natural PSII‐enriched thylakoid membranes (PSII BBY) is demonstrated. Superfine m‐WO3 NPs (≈1–2 nm) are introduced into PSII BBY. Transmission electron microscopy (TEM) measurements showed that even the highest concentrations of NPs used did not degrade the PSII BBY membranes. Using atomic force microscopy (AFM), it is shown that the organization of PSII BBY depends strongly on the concentration of NPs applied. This proved that the superfine NPs can easily penetrate the thylakoid membrane and interact with its components. These changes are also related to the modified energy transfer between the external light‐harvesting antennas and the PSII reaction center, shown by absorption and fluorescence experiments. The biohybrid system shows stability at pH 6.5, the native operating environment of PSII, so a high rate of O2 evolution is expected. In addition, the light‐induced water‐splitting process can be further stimulated by the direct interaction of superfine WO3 NPs with the donor and acceptor sides of PSII. The water‐splitting activity and stability of this colloidal system are under investigation.Research Highlights The phenomenon of the self‐organization of a biohybrid system composed of thylakoid membranes enriched in photosystem II and superfine WO3 nanoparticles is studied using AFM and TEM. A strong dependence of the organization of PSII complexes within PSII BBY membranes on the concentration of NPs applied is observed. This observation turns out to be crucial to understand the complexity of the mechanism of the action of WO3 NPs on modifications of energy transfer from external antenna complexes to the PSII reaction center.

$Research paper thumbnail of Multifractal characterization of morphology of human red blood cells membrane skeleton$

Journal of Microscopy, 2015

SummaryThe purpose of this paper is to show applicability of multifractal analysis in investigati... more SummaryThe purpose of this paper is to show applicability of multifractal analysis in investigations of the morphological changes of ultra‐structures of red blood cells (RBCs) membrane skeleton measured using atomic force microscopy (AFM). Human RBCs obtained from healthy and hypertensive donors as well as healthy erythrocytes irradiated with neutrons (45 μGy) were studied. The membrane skeleton of the cells was imaged using AFM in a contact mode. Morphological characterization of the three‐dimensional RBC surfaces was realized by a multifractal method. The nanometre scale study of human RBCs surface morphology revealed a multifractal geometry. The generalized dimensions Dq and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of their membrane skeleton organization. Surface characterization was made using areal ISO 25178‐2: 2012 topography parameters in combination with AFM topography measurement. The surface structure of human ...

Applied Organometallic Chemistry, 2002

Organometals are known to cause lysis of cells, but the molecular mechanism of their action is no... more Organometals are known to cause lysis of cells, but the molecular mechanism of their action is not recognized. In this work, we have examined the interaction of triphenyltin with erythrocyte membranes. We determined the order of haemolytic activity of the investigated organometal species as being: triphenyllead > tripropyltin = triphenyltin > triethyllead > trimethyltin. Such an order suggests that the haemolytic activity increases with the increasing hydrophobicity of the organic ligands. Compounds containing lead are more toxic than the respective complexes of tin. Triphenyltin chloride (Ph3SnCl) is very effective in lysis of erythrocytes. Using 119Sn Mössbauer spectroscopy we showed that triphenyltin interacts with the protein components of pig erythrocyte membranes in a highly specific way, but we did not detect any interaction of triphenyltin with pig haemoglobin. The Mössbauer spectrum was fitted with a single doublet characterized by hyperfine parameters that differ ...

Biochimica et Biophysica Acta (BBA) - Bioenergetics, 2010

Non-heme iron is a conservative component of type II photosynthetic reaction centers of unknown f... more Non-heme iron is a conservative component of type II photosynthetic reaction centers of unknown function. We found that in the reaction center from Rba. sphaeroides it exists in two forms, high and low spin ferrous states, whereas in Rsp. rubrum mostly in a low spin state, in line with our earlier finding of its low spin state in the algal photosystem II reaction center (Burda et al., 2003). The temperature dependence of the nonheme iron displacement studied by Mössbauer spectroscopy shows that the surrounding of the high spin iron is more flexible (Debye temperature~165 K) than that of the low spin atom (~207 K). Nuclear inelastic scattering measurements of the collective motions in the Rba. sphaeroides reaction center show that the density of vibrational states, originating from non-heme iron, has well-separated modes between lower (4-17 meV) and higher (17-25 meV) energies while in the one from Rsp. rubrum its distribution is more uniform with only little contribution of low energy (~6 meV) vibrations. It is the first experimental evidence that the fluctuations of the protein matrix in type II reaction center are correlated to the spin state of non-heme iron. We propose a simple mechanism in which the spin state of non-heme iron directly determines the strength of coupling between the two quinone acceptors (Q A and Q B) and fast collective motions of protein matrix that play a crucial role in activation and regulation of the electron and proton transfer between these two quinones. We suggest that hydrogen bond network on the acceptor side of reaction center is responsible for stabilization of non-heme iron in different spin states.

Journal of Applied Physics, Oct 15, 1995

Ti and TiN layers implanted with 57Fe ions were studied by conversion electron Mössbauer spectros... more Ti and TiN layers implanted with 57Fe ions were studied by conversion electron Mössbauer spectroscopy at 295 and 80 K. In as-implanted Ti samples the local states of iron implants were assigned to α-Ti(Fe) and β-Ti(Fe). In TiN, about 68% of iron implants replace Ti atoms forming Fe2N and nonstoichiometric Fe–N complexes. The remaining Fe ions replace N atoms exhibiting α-Ti(Fe) and β-Ti(Fe) states. The protective properties of the TiN cover layer are discussed in terms of changes of the these states after subsequent annealing in air.

Journal of Analytical Atomic Spectrometry, 2016

Phototrophic bacteria are metabolically diverse microorganisms that attract substantial attention... more Phototrophic bacteria are metabolically diverse microorganisms that attract substantial attention due to their growing potential in scientific and industrial applications. In the present study, total reflection X-ray fluorescence (TXRF) spectrometry was applied to perform a comprehensive analysis of the trace elements content of purple non-sulphur phototrophic bacteria, their chromatophores and selected photosynthetic structures in response to alterations in oxygen growth conditions. There is a lack of consistent information on the content of microelements, their distribution and in particular correlations between them. This analysis, carried out on the Rhodobacter sphaeroides species aims to rectify this. Qualitative examination revealed the presence of microelements generally not considered as basic in the bacterial ionome. Quantitative inspection pointed to Fe as the major trace element in this phototrophic species irrespective of growth conditions (sample type). The K/Rb and Ca/Sr ratios were determined for the first time for bacteria and their photosynthetic membranes. Finally, the ionomic approach to elemental accumulation followed by statistical analysis revealed intriguing relationships between the elements within cells and phototrophic membranes. The vast potential and usefulness of the TXRF technique in a wide range of biological and environmental applications is underlined.

Biochimica Et Biophysica Acta - Bioenergetics, Dec 1, 2012

We investigate the dynamical properties of the non-heme iron (NHFe) in His-tagged photosynthetic ... more We investigate the dynamical properties of the non-heme iron (NHFe) in His-tagged photosynthetic bacterial reaction centers (RCs) isolated from Rhodobacter (Rb.) sphaeroides. Mössbauer spectroscopy and nuclear inelastic scattering of synchrotron radiation (NIS) were applied to monitor the arrangement and flexibility of the NHFe binding site. In His-tagged RCs, NHFe was stabilized only in a high spin ferrous state. Its hyperfine parameters (IS = 1.06 ± 0.01 mm/s and QS = 2.12 ± 0.01 mm/s), and Debye temperature (θ D0~1 67 K) are comparable to those detected for the high spin state of NHFe in non-His-tagged RCs. For the first time, pure vibrational modes characteristic of NHFe in a high spin ferrous state are revealed. The vibrational density of states (DOS) shows some maxima between 22 and 33 meV, 33 and 42 meV, and 53 and 60 meV and a very sharp one at 44.5 meV. In addition, we observe a large contribution of vibrational modes at low energies. This iron atom is directly connected to the protein matrix via all its ligands, and it is therefore extremely sensitive to the collective motions of the RC protein core. A comparison of the DOS spectra of His-tagged and non-His-tagged RCs from Rb. sphaeroides shows that in the latter case the spectrum was overlapped by the vibrations of the heme iron of residual cytochrome c 2 , and a low spin state of NHFe in addition to its high spin one. This enabled us to pinpoint vibrations characteristic for the low spin state of NHFe.

Zeitschrift für Naturforschung C, Jun 1, 1992

The amperometric analysis o f photosynthetic oxygen evolution in thylakoid membrane preparations ... more The amperometric analysis o f photosynthetic oxygen evolution in thylakoid membrane preparations o f tobacco, sedimented on a large surface electrode, shows that the oxygen signal is preceded by a lag phase o f 1.2 ms. As the used tobacco lamellar systems have an average diameter o f 4-5 j^m this lag phase is interpreted to be due to an average distance o f 2.4 (am between oxygen emitting sources and the electrode surface. This interpretation o f the lag phase is substantiated by the fact that photosystem I-mediated oxygen uptake in the same prepara tion measured with the same amperometric technique exhibits the same lag phase although the kinetic uptake parameters are considerably slower than those o f oxygen evolution due to the water-splitting reaction. The analysis o f the oxygen evolution signal shows that the sedimenta tion time i.e. the quality o f the contact o f the source with the electrode is decisive for the meas ured value for the oxygen release time, which with this method without much effort comes out to be certainly not longer than 1.5 ms. A computer simulation shows that the distance o f the oxygen emitting layer from the electrode as well as its thickness and the actual release time are variables which influence practically all parameters (signal shape, amplitude etc.) o f such am perometric signals. From this it appears that the determined apparent experimental parame ters o f oxygen evolution kinetics contain deform ations due to the thickness o f the sample and the diffusion distance from the electrode. An extrapolation calculated for a sample o f infinite thinness separated from the electrode by a minimal distance o f 0.001 |am with x o f 5.5 ms yields a lower limit value for the half-rise time o f 0.5 ms, a value which has been experimentally determined by EPR oximetry (K.

Acta Biologica Cracoviensia. Series Botanica. Supplement, 2011

De-epoxidases of xanthophyll cycles require non-bilayer lipids for their activity Using an in vit... more De-epoxidases of xanthophyll cycles require non-bilayer lipids for their activity Using an in vitro system to study lipid dependence of the xanthophyll cycle de-epoxidase activity, such as violaxanthin de-epoxidase (VDE) and diadinoxanthin de-epoxidase (DDE), we found that replacement of monogalactosyldiacylglycerol (MGDG) with digalactosyldiacylglycerol (DGDG) or phosphatidylcholine (PC) in the assay medium resulted in a strong inhibition of xanthophyll cycle pigments, violaxanthin (Vx) and diadinoxanthin (Dx), de-epoxidation. On the other hand, replacement of MGDG with phosphatidylethanolamine (PE) sustained a high activity of these enzymes, in spite of the very different chemical character of these two lipids. We have also found that Ddx and Vx solubility in lipids depends on the lipid species used. Using phosphorus NMR measurements, we detected the existence of the inverted hexagonal phase (H II) in a binary (MGDG/PC) lipid mixture as well as in thylakoid membranes. The obtained results clearly indicate that only H II forming lipids (MGDG and PE) may effectively support Vx or Ddx de-epoxidation, whereas bilayer-forming lipids (DGDG and PC) are not effective in this process. Hence, a conclusion is drawn that VDE and DDE activity depends not on the chemical character of lipids but on the kind of structure they form in water environment. VDE and DDE constitute a new family of enzymes whose activity depends on the presence of inverted hexagonal structures of lipids. We propose a molecular model of Vx and Dx de-epoxidation in which H II forming lipids play a crucial role.

Zeitschrift für Naturforschung C, Dec 1, 1996

Five characteristic discontinuities of the pattern of oxygen evolution have been detected for the... more Five characteristic discontinuities of the pattern of oxygen evolution have been detected for the filamentous cyanobacterium Oscillatoria chalybea in the temperature range of 0°C to 30°C. The temperatures at which these discontinuities occur are: ~ 5°C, ~ 11°C, ~ 15°C, 2 1°C and ~ 25°C. The calculated initial 5-S state distribution, the miss parameter and the fraction of the fast transition S3-> S0 + 0 2 are affected. The discontinuities are observed at the same transition temperature also for Chlorella kessleri hence are not specific for the cyanobacterium. Based on these studies it is concluded that the not vanishing oxygen signal under the first flash of a flash train in Oscillatoria cannot have its origin in interactions between oxygen-evolving complexes. A decrease of temperature should slow down the ex pected charge exchanges, improve the oscillations, thus reduce or lower the first two oxygen amplitudes of the oscillatoria pattern. Lowering of the temperautres improves the oscillations but does not lower the first 0 2 signal of the pattern.

Zeitschrift für Naturforschung C, Apr 1, 1995

Calcium-Binding Sites, Photosystem II, Tobacco, Oxygen Evolution. S-States Trivalent lanthanide c... more Calcium-Binding Sites, Photosystem II, Tobacco, Oxygen Evolution. S-States Trivalent lanthanide cations are suitable probes for C a2+-binding sites in photosystem II (PS II). PS II membranes prepared from Nicoticinci tabacum, intact and depleted of the extrinsic polypeptides were exposed to lanthanide ions (D y3+ and E u 3+). Small concen trations of dysprosium and europium ions enhance oxygen evolution under short saturating flashes. Higher concentrations of the rare earth cations cause the release of the three extrinsic peptides (17, 23 and 33 kDa) and reduce 0 2 yield. The reactivation of the PS II membranes, thus depleted of the 33 kDa subunit, by Ca2+ ions is not possible. Comparing E u 3+ with Dy3+ in this effect shows that E u 3+ is m ore effective than Dy3+, because a lower E u 3+-concentration in comparison to that of Dy3+ inactivates 0 2-evolution. The differences between europium and dysprosium can be explained by their different ionic radius. Our results suggest the existence of two Ca-binding regions: one with a low affinity for calcium would be located on the contact surface of the 23 and 33 kDa proteins and the second one with a high affinity, should be located close to the Mn-cluster and to tyrosine-161 (Z). The more tightly-bound calcium would be responsible for the activity of the PS II system.

By combining structural and phylogenetic analyses, we have earlier clarified the evolutionary rel... more By combining structural and phylogenetic analyses, we have earlier clarified the evolutionary relationships among membrane enzymes that couple the transmembrane transfer of protons or sodium ions with the synthesis/hydroly-sis of ATP. A comparison of the structures of the sodium-dependent bacterial and archaeal ATPases revealed nearly identical sets of amino acids involved in sodium binding. Phylogenetic analysis showed that the sodium-dependent ATPases are scattered among proton-dependent ATPases in both the archaeal and bacterial branches of the phylo-genetic tree [1–3]. Barring convergent emergence of the same set of amino acid ligands in several lineages, these findings indicate that the common ancestor of rotary ATPases should have possessed a sodium-binding site. A focused search for primitive sodium-translocating ATPases/ATP synthases among microbial genomes identified an atypical form of a rotary ATPase that is present in a number of phylogenetically diverse marine, halotole...

Polish Journal of Natural Sciences. Supplement, 2003

Acta Biochimica Polonica, 2012

The effect of carotenoids on stability of model photosynthetic pigment-protein complexes subjecte... more The effect of carotenoids on stability of model photosynthetic pigment-protein complexes subjected to chemical oxidation with hydrogen peroxide or potassium ferricyanide was investigated. The oxidation of carotenoid-less and carotenoid-containing complexes was conducted in the presence or absence of ascorbic acid. The progress of the reactions was monitored by use of absorption and fluorescence spectroscopy. Our results show that carotenoids may significantly enhance the stability of photosynthetic complexes against oxidation and their protective (antioxidant) effect depends on the type of the oxidant.

Zeitschrift für Naturforschung C, 1997

α-Tocoquinone (α-TQ ) and α-tocopherol (α-TOC) which cannot substitute for plastoquinone-9 (PQ-A)... more α-Tocoquinone (α-TQ ) and α-tocopherol (α-TOC) which cannot substitute for plastoquinone-9 (PQ-A) as an electron acceptor from photosystem II (PS II), influence the oxygen evolution activity of thylakoid membranes under continuous illumination. In the presence of the herbicide DCMU and the protonophore FCCP which stimulate cyclic electron transport around PS II, α-TQ decreased oxygen evolution whereas α-TOC enhanced it. The effects are attributed to a stimulation or an inhibition of cyclic electron transport around PS II by α-TQ and α-TOC, respectively. Results of flash light experiments on PS II preparations show that both α-TQ and α-TOC increased the d-parameter which describes the transition probability from the S3- to the S0-state of the oxygen-evolving complex, although to a smaller extent when PQ-A is added alone to the preparations. The initial S-state distribution in darkadapted samples was changed only upon PQ-A addition and influenced neither by α-TQ nor by α-TO C suppleme...