Search results

1

Inhibition of transcription starting from bacteriophage λ pR promoter during the stringent response in Escherichia coli: implications for λ DNA replication

100%

Szalewska-Pałasz A., Węgrzyn G.

Acta Biochimica Polonica

|

1995

|

vol. 42

|

issue 2

233-239

2

The Obg subfamily of bacterial GTP-binding proteins: essential proteins of largely unknown functions that are evolutionarily conserved from bacteria to humans.

100%

Czyż A., Węgrzyn G.

|

2005

|

vol. 52

|

issue 1

35-43

EN

Members of the Obg subfamily of small GTP-binding proteins (called Obg, CgtA, ObgE or YhbZ in different bacterial species) have been found in various prokaryotic and eukaryotic organisms, ranging from bacteria to humans. Although serious changes in phenotypes are observed in mutant bacteria devoid of Obg or its homologues, specific roles of these GTP-binding proteins remain largely unknown. Recent genetic and biochemical studies, as well as determination of the structures of Obg proteins from Bacillus subtilis and Thermus thermophilus, shed new light on the possible functions of the members of the Obg subfamily and may constitute a starting point for the elucidation of their exact biological role.

3

An introduction to DNA chips: principles, technology, applications and analysis.

100%

Gabig M., Węgrzyn G.

|

2001

|

vol. 48

|

issue 3

615-622

EN

This review describes the recently developed GeneChip technology that provides efficient access to genetic information using miniaturised, high-density arrays of DNA or oligonucleotide probes. Such microarrays are powerful tools to study the molecular basis of interactions on a scale that would be impossible using conventional analysis. The recent development of the microarray technology has greatly accelerated the investigation of gene regulation. Arrays are mostly used to identify which genes are turned on or off in a cell or tissue, and also to evaluate the extent of a gene's expression under various conditions. Indeed, this technology has been successfully applied to investigate simultaneous expression of many thousands of genes and to the detection of mutations or polymorphisms, as well as for their mapping and sequencing.

4

Changes is genes coding for laccases 1 and 2 may contribute to deformation and reduction of wings in apollo butterfly (Parnassius apollo, Lepidoptera: Papilionidae) from the isolated population in Pieniny National Park (Poland)

100%

Łukasiewicz K., Węgrzyn G.

|

2016

|

vol. 63

|

issue 1

177-180

EN

An isolated population of apollo butterfly (Parnassius apollo, Lepidoptera: Papilionidae) occurs in Pieniny National Park (Poland). Deformations and reductions of wings in a relatively large number of individuals from this population is found, yet the reasons for these defects are unknown. During studies devoted to identify cause(s) of this phenomenon, we found that specific regions of genes coding of enzymes laccases 1 and 2 could not be amplified from DNA samples isolated from large fractions of malformed insects while expected PCR products were detected in almost all (with one exception) normal butterflies. Laccases (p-diphenol:dioxygen oxidoreductases) are oxidases containing several copper atoms. They catalyse single-electron oxidations of phenolic or other compounds with concomitant reduction of oxygen to water. In insects, their enzymatic activities were found previously in epidermis, midgut, Malpighian tubules, salivary glands, and reproductive tissues. Therefore, we suggest that defects in genes coding for laccases might contribute to deformation and reduction of wings in apollo butterflies, though it seems obvious that deficiency in these enzymes could not be the sole cause of these developmental improperties in P. apollo from Pieniny National Park.

5

Elektryczne biochipy

100%

Łoś M., Węgrzyn G.

|

EN

Rapid detection and quantification of microorganisms, particularly their nucleic acids and proteins, appears to be crucial in clinical practice, veterinary medicine, agriculture, basic research as well as in biotechnological factories. Although various techniques were described and are currently used, development of more rapid, more sensitive and quantitative methods seems to be still important. Here we describe a method for rapid detection of nucleic acids, proteins and small molecules, based on electrical biochip technology. This method is quick and sensitive. It can be thus expected that electrical bio-chips will soon be commonly used in biotechnology and medicine.

6

A method for isolation of plasmid DNA replication intermediates from unsynchronized bacterial cultures for electron microscopy analysis

81%

Śrutkowska S., Konopa G., Węgrzyn G.

Acta Biochimica Polonica

|

1998

|

vol. 45

|

issue 1

233-240

7

Combined effect of stringent or relaxed response, temperature and rom function on the replication of pUC plasmids in Escherichia coli

81%

Herman A., Węgrzyn A., Węgrzyn G.

Acta Biochimica Polonica

|

1994

|

vol. 41

|

issue 2

122-124

8

Staphylococcus aureus as an infectious agent: overview of biochemistry and molecular genetics of its pathogenicity

81%

Plata K., Rosato A., Węgrzyn G.

|

issue 4

597-612

EN

Although it is estimated that 20-30% of the general human population are carriers of Staphylococcus aureus, this bacterium is one of the most important etiological agents responsible for healthcare-associated infections. The appearance of methicillin resistant S. aureus (MRSA) strains has created serious therapeutical problems. Detailed understanding of the mechanisms of S. aureus infections seems necessary to develop new effective therapies against this pathogen. In this article, we present an overview of the biochemical and genetic mechanisms of pathogenicity of S. aureus strains. Virulence factors, organization of the genome and regulation of expression of genes involved in virulence, and mechanisms leading to methicilin resistance are presented and briefly discussed.

9

Characterization of conditions and determination of practical tips for mtDNA level estimation in various human cells

81%

Jędrak P., Sowa N., Barańska S., Węgrzyn G.

|

2017

|

vol. 64

|

issue 4

699-704

EN

Determination of mtDNA copy number in the cell is crucial to understand many cellular processes. Recently, the number of studies with the use of mitochondrial DNA (mtDNA) content as the determinant of mitochondrial abnormalities increased greatly and is still growing, therefore, optimization of technical conditions for this analysis is crucial. Despite using similar laboratory protocols, some results cannot be compared between research centers, thus causing discrepancies in the assessment of mtDNA content. The aim of this work was to test which conditions of biological sample collection and storage affect estimation of mtDNA level relative to the nuclear DNA (nDNA) in the blood samples and dermal fibroblasts. We found that the time and temperature of sample storage, as well as the type of the blood sample (whole blood or leukocytes) influence the estimate of mtDNA/nDNA ratio in the blood. In the case of dermal fibroblasts collected from healthy control and Huntington disease patients, our data indicate that the passage number of cells is essential to obtain reliable results.

10

Non-random distribution of GATC sequences in regions of promoters stimulated by the SeqA protein of Escherichia coli.

81%

Strzelczyk B., Słomińska-Wojewódzka M., Węgrzyn G., Węgrzyn A.

|

2003

|

vol. 50

|

issue 4

941-945

EN

The SeqA protein of Escherichia coli is not only the main negative regulator of DNA replication initiation but also a specific transcription factor. It binds to hemimethylated GATC sequences and, with somewhat different specificity, to fully methylated GATC regions. Recently, a microarray analysis was reported, in which transcriptomes of wild-type and ΔseqA strains were compared. Although in the seqA mutant the levels of some transcripts were significantly decreased while certain transcripts were evidently more abundant relative to wild-type bacteria, no correlation between the presence of GATC motifs in promoter sequences and transcription activity was found. However, here we show that when larger DNA fragments, encompassing positions from -250 to +250 relative to the transcription start site, are analyzed, some common features of GATC distribution near the promoters activated by SeqA can be demonstrated. Nevertheless, it seems that the GATC pattern is not the only determinant of SeqA-dependence of promoter activity.

11

Effect of coliphage λP gene mutations on the stability of the λO protein, theinitiator of λDNA replication

80%

Pawłowicz A., Węgrzyn G., Taylor K.

|

vol. 40

|

issue 1

29-31

12

Biochemical and genetic analysis of λ_W, the newly isolated lambdoid phage

70%

Wróbel B., Śrutkowska S., Węgrzyn G.

Acta Biochimica Polonica

|

1998

|

vol. 45

|

issue 1

251-259

13

The Escherichia coli RNA polymerase α subunit and transcriptional activation by bacteriophage λ CII protein

62%

Gabig M., Obuchowski M., Ciesielska A., Latała B., Węgrzyn2 A., Thomas M. S., Węgrzyn G.

Acta Biochimica Polonica

|

1998

|

vol. 45

|

issue 1

271-280

14

Methylxanthines (caffeine, pentoxifylline and theophylline) decrease the mutagenic effect of daunomycin, doxorubicin and mitoxantrone

62%

Piosik J., Gwizdek-Wiśniewska A., Ulanowska K., Ochociński J., Czyż A., Węgrzyn G.

|

2005

|

vol. 52

|

issue 4

923-926

EN

Previously performed experiments showed that methylxanthines, especially caffeine, may protect cells against cytostatic or cytotoxic effects of several aromatic compounds. One of the proposed mechanisms of this protection is based on stacking interactions between π electron systems of polycyclic aromatic molecules. In this work, we demonstrate that caffeine and other methylxanthines - pentoxifylline and theophylline - significantly decrease mutagenicity of the anticancer aromatic drugs daunomycin, doxorubicin and mitoxantrone. The spectrophotometric titration of these aromatic compounds by methylxanthines indicated formation of mixed aggregates. The concentrations of free active forms of the drugs decreased when the concentrations of methylxanthines increased in the mixture. Therefore, likely methylxanthines may play a role of scavengers of the free active forms of daunomycin, doxorubicin and mitoxantrone.

15

Improved HPLC method for total plasma homocysteine detection and quantification

62%

Sawuła W., Banecka-Majkutewicz Z., Kadziński L., Jakóbkiewicz-Banecka J., Węgrzyn G., Nyka W., Banecki B.

|

2008

|

vol. 55

|

issue 1

119-126

EN

Recent clinical research has pointed at hyperhomocysteinemia as an independent risk factor in a number of cardiovascular and neurological diseases. We have improved a chromatographic method of total plasma homocysteine measurements in order to obtain higher sensitivity, reliability and reproducibility. The method demonstrates excellent linearity (R = 0.999), range (< 2-100 µM), precision (instrumental RSD 0.06 and method RSD 1.17), accuracy (recovery of 99.92 and RSD 1.27), reproducibility, quantification limit and ruggedness (e.g. pH from 2.0 to 2.5). Because even a small increase in homocysteine level can be a significant risk factor of cardiovascular diseases, such a precise method is required. The constructed method allows the measurement of plasma pyridoxal phosphate, PLP, the co-enzyme form of vitamin B6, on the same column and similar reagents. The developed method has been successfully applied to measure both total plasma and serum homocysteine in a group of acute stroke patients.

16

Differential effects of various soy isoflavone dietary supplements (nutraceuticals) on bacterial growth and human fibroblast viability

62%

Pierzynowska K., Rzeszótko A., Blendowska A., Wieczerzak E., Rodziewicz-Motowidło S., Piotrowska E., Węgrzyn G.

|

2018

|

vol. 65

|

issue 2

325-332

EN

Flavonoids, polyphenolic compounds present in many food products, affect growth of different bacterial species when tested as purified or synthetic substances. They can also influence gene expression in human cells, like fibroblasts. Here, we asked if soy isoflavone extracts, commonly used in many products sold as anti-menopausal dietary supplements, influence bacterial growth similarly to a synthetic isoflavone, genistein. Four commercially available products were tested in amounts corresponding to genistein concentrations causing inhibition of growth of Vibrio harveyi (a model bacterium sensitive to this isoflavone) and Escherichia coli (a model bacterium resistant to genistein). Differential effects of various extracts on V. harveyi and E. coli growth, from stimulation, to no changes, to inhibition, were observed. Moreover, contrary to genistein, the tested extracts caused a decrease (to different extent) in viability of human dermal fibroblasts. These results indicate that effects of various soy isoflavone extracts on bacterial growth and viability of human cells are different, despite similar declared composition of the commercially available products.

17

Replication of λ plasmid in amino acid-starved strains of Escherichia coli

61%

Węgrzyn G., Kwaśnik E., Taylor K.

|

18

Eriochrome black T as a dye for agarose gel electrophoresis

60%

Obuchowski M., Węgrzyn G.

Acta Biochimica Polonica

|

1991

|

vol. 38

|

issue 1

177-179

19

Introduction - Plasmids

60%

Węgrzyn G.

Kosmos

|

2002

|

vol. 51

|

issue 3

229-230

20

Wstęp - Plazmidy

60%

Węgrzyn G.

Kosmos

|

2002

|

vol. 51

|

issue 3

227-228

Refine search results

Inhibition of transcription starting from bacteriophage λ pR promoter during the stringent response in Escherichia coli: implications for λ DNA replication

The Obg subfamily of bacterial GTP-binding proteins: essential proteins of largely unknown functions that are evolutionarily conserved from bacteria to humans.

An introduction to DNA chips: principles, technology, applications and analysis.

Changes is genes coding for laccases 1 and 2 may contribute to deformation and reduction of wings in apollo butterfly (Parnassius apollo, Lepidoptera: Papilionidae) from the isolated population in Pieniny National Park (Poland)

Elektryczne biochipy

A method for isolation of plasmid DNA replication intermediates from unsynchronized bacterial cultures for electron microscopy analysis

Combined effect of stringent or relaxed response, temperature and rom function on the replication of pUC plasmids in Escherichia coli

Staphylococcus aureus as an infectious agent: overview of biochemistry and molecular genetics of its pathogenicity

Characterization of conditions and determination of practical tips for mtDNA level estimation in various human cells

Non-random distribution of GATC sequences in regions of promoters stimulated by the SeqA protein of Escherichia coli.

Effect of coliphage λP gene mutations on the stability of the λO protein, theinitiator of λDNA replication

Biochemical and genetic analysis of λ_W, the newly isolated lambdoid phage

The Escherichia coli RNA polymerase α subunit and transcriptional activation by bacteriophage λ CII protein

Methylxanthines (caffeine, pentoxifylline and theophylline) decrease the mutagenic effect of daunomycin, doxorubicin and mitoxantrone

Improved HPLC method for total plasma homocysteine detection and quantification

Differential effects of various soy isoflavone dietary supplements (nutraceuticals) on bacterial growth and human fibroblast viability

Replication of λ plasmid in amino acid-starved strains of Escherichia coli

Eriochrome black T as a dye for agarose gel electrophoresis

Introduction - Plasmids

Wstęp - Plazmidy