Specific DNA-protein interactions are vital for cellular life maintenance processes, such as transcriptional regulation, chromosome maintenance, replication and DNA repair, and their monitoring gives valuable information on molecular-level organization of those processes. Here, we propose a new method of label-free electrochemical sensing of sequence specific binding between the lysozyme protein and a single stranded DNA aptamer specific for lysozyme (DNAapta) that exploits the constant current chronopotentiometric stripping (CPS) analysis at modified mercury electrodes. Specific lysozyme-DNAapta binding was distinguished from nonspecific lysozyme-DNA interactions at thioglycolic acid-modified mercury electrodes, but not at the dithiothreitol-modified or bare mercury electrodes. Stability of the surface-attached lysozyme-DNAapta layer depended on the stripping current (Istr) intensity, suggesting that the integrity of the layer critically depends on the time of its exposure to negative potentials. Stabilities of different lysozyme-DNA complexes at the negatively polarized electrode surface were tested, and it was shown that structural transitions of the specific lysozyme-DNAapta complexes occur in the Istr ranges different from those observed for assemblies of lysozyme with DNA sequences capable of only nonspecific lysozyme-DNA interactions. Thus, the CPS allows distinct discrimination between specific and non-specific protein-DNA binding and provides valuable information on stability of the nucleic acid-protein interactions at the polarized interfaces.

• Klíčová slova
• Aptamer, Catalytic hydrogen evolution, Constant current chronopotentiometric stripping, DNA-protein interactions, Lysozyme, Thiol-modified mercury electrodes,
• MeSH
• aptamery nukleotidové genetika   metabolismus   MeSH
• elektrochemie přístrojové vybavení   metody   MeSH
• elektrody MeSH
• muramidasa metabolismus   MeSH
• rtuť chemie   MeSH
• sekvence nukleotidů MeSH
• substrátová specifita MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aptamery nukleotidové MeSH
• muramidasa MeSH
• rtuť MeSH

Neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), or systemic amyloidosis, are characterized by the specific protein transformation from the native state to stable insoluble deposits, e.g., amyloid plaques. The design of potential therapeutic agents and drugs focuses on the destabilization of the bonds in their beta-rich structures. Surprisingly, ferritin derivatives have recently been proposed to destabilize fibril structures. Using atomic force microscopy (AFM) and fluorescence spectrophotometry, we confirmed the destructive effect of reconstructed ferritin (RF) and magnetoferritin (MF) on lysosome amyloid fibrils (LAF). The presence of iron was shown to be the main factor responsible for the destruction of LAF. Moreover, we found that the interaction of RF and MF with LAF caused a significant increase in the release of potentially harmful ferrous ions. Zeta potential and UV spectroscopic measurements of LAF and ferritin derivative mixtures revealed a considerable difference in RF compared to MF. Our results contribute to a better understanding of the mechanism of fibril destabilization by ferritin-like proteins. From this point of view, ferritin derivatives seem to have a dual effect: therapeutic (fibril destruction) and adverse (oxidative stress initiated by increased Fe2+ release). Thus, ferritins may play a significant role in various future biomedical applications.

• Klíčová slova
• destruction, ferritin, iron release, lysozyme amyloid fibrils, magnetoferritin, reconstructed ferritin,
• MeSH
• amyloid * metabolismus   MeSH
• ferritin MeSH
• muramidasa * chemie   MeSH
• železo metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amyloid * MeSH
• ferritin MeSH
• magnetoferritin MeSH Prohlížeč
• muramidasa * MeSH
• železo MeSH

Some methodological aspects of an on-line combination of capillary zone electrophoresis with mass spectrometric detection (CZE-QqQ-MS) were studied in this work as well as the possibilities of using this combination for analysis of the high-molecular mass compounds present in multi-component matrices. All experiments using an on-line combination of capillary electrophoresis with mass spectrometric detection were carried out in cationic mode in covalently-coated capillary. The optimised electrolyte system consisted of 100 mmol/L formic acid. Prior to the CZE-QqQ-MS analysis, an extraction of lysozyme from cheese samples using 1 mol/L of acetic acid was performed. The LOD was 3.6 mg lysozyme per kg and the LOQ was 10.9 mg lysozyme per kg. The concentration range of the lysozyme determined in four cheese samples analysed in this work was from 0.5 to 3.3g of lysozyme per kg. The values of the relative standard deviations thus obtained were from 4.6% to 9.3% depending on the cheese sample.

• Klíčová slova
• Capillary zone electrophoresis, Cheese, Lysozyme, Mass spectrometry, Multi-component matrices,
• MeSH
• elektroforéza kapilární metody   MeSH
• hmotnostní spektrometrie metody   MeSH
• kur domácí MeSH
• muramidasa analýza   MeSH
• potravinářské konzervační látky analýza   MeSH
• sýr analýza   MeSH
• vaječné proteiny analýza   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• muramidasa MeSH
• potravinářské konzervační látky MeSH
• vaječné proteiny MeSH

Resistance of microorganisms to antibiotics has increased. The use of natural components with antimicrobial properties can be of great significance to reduce this problem. The presented work is focused on the study of the effect of encapsulation of selected plant and animal antimicrobial substances (herbs, spices, lysozyme and nisin) on their activity and stability. Antimicrobial components were packaged into liposomes and polysaccharide particles (alginate, chitosan and starch). Antimicrobial activity was tested against two Gram-positive (Bacillus subtilis and Micrococcus luteus) and two Gram-negative (Escherichia coli and Serratia marcescens) bacteria. Encapsulation was successful in all types of polysaccharide particles and liposomes. The prepared particles exhibited very good long-term stability, especially in aqueous conditions. Antimicrobial activity was retained in all types of particles. Liposomes with encapsulated herb and spice extracts exhibited very good inhibitory effect against all tested bacterial strains. Most of herbal extracts had very good antimicrobial effect against the tested Gram-negative bacterial strains, while Gram-positive bacteria were more sensitive to lysozyme particles. Thus, particles with co-encapsulated herbs and lysozyme are more active against different types of bacteria, and more stable and more effective during long-term storage. Particles with encapsulated mixture of selected plant extracts and lysozyme could be used as complex antimicrobial preparation with controlled release in the production of food and food supplements, pharmaceutical and cosmetic industries.

• Klíčová slova
• antimicrobial effect, encapsulation, herbs, liposomes, lysozyme, organic particles,
• Publikační typ
• časopisecké články MeSH

The tear film is a thin multilayered structure covering the cornea. Its outermost layer is a lipid film underneath of which resides on an aqueous layer. This tear film lipid layer (TFLL) is itself a complex structure, formed by both polar and nonpolar lipids. It was recently suggested that due to tear film dynamics, TFLL contains inhomogeneities in the form of polar lipid aggregates. The aqueous phase of tear film contains lachrymal-origin proteins, whereby lysozyme is the most abundant. These proteins can alter TFLL properties, mainly by reducing its surface tension. However, a detailed nature of protein-lipid interactions in tear film is not known. We investigate the interactions of lysozyme with TFLL in molecular details by employing coarse-grained molecular dynamics simulations. We demonstrate that lysozyme, due to lateral restructuring of TFLL, is able to penetrate the tear lipid film embedded in inverse micellar aggregates.

• Klíčová slova
• Lipid-protein interaction, Lysozyme, Molecular dynamics, Tear film, Tear film lipid layer,
• MeSH
• adsorpce MeSH
• estery cholesterolu chemie   MeSH
• fosfatidylcholiny chemie   MeSH
• fosfatidylethanolaminy chemie   MeSH
• kinetika MeSH
• lidé MeSH
• muramidasa chemie   MeSH
• povrchové napětí MeSH
• sfingomyeliny chemie   MeSH
• simulace molekulární dynamiky * MeSH
• slzy chemie   MeSH
• sulfoglykosfingolipidy chemie   MeSH
• termodynamika MeSH
• triolein chemie   MeSH
• voda chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1-palmitoyl-2-oleoylphosphatidylcholine MeSH Prohlížeč
• 1-palmitoyl-2-oleoylphosphatidylethanolamine MeSH Prohlížeč
• cholesteryl oleate MeSH Prohlížeč
• estery cholesterolu MeSH
• fosfatidylcholiny MeSH
• fosfatidylethanolaminy MeSH
• muramidasa MeSH
• sfingomyeliny MeSH
• sulfoglykosfingolipidy MeSH
• triolein MeSH
• voda MeSH

The level of lysozyme in fat body, hemocytes and cell-free hemolymph from Galleria mellonella larvae infected with Pseudomonas aeruginosa was determined and evaluated. In the samples of fat body and hemocytes, an increase in lysozyme content was detected 1 d after infection and then a significant decrease was observed after a prolonged infection time. In the case of cell-free hemolymph, an increase in the lysozyme level was noticeable during the first 30 h post injection and stayed at a similar level for 42 h. The smaller decrease of the lysozyme level after 42 h might be associated with the development of bacteremia of P. aeruginosa in insects. In addition, the gradual increase in the content of lysozyme correlated with the increase of its activity in the hemolymph of the infected larvae as a response to injection with P. aeruginosa. The G. mellonella lysozyme appeared to be insensitive to extracellular proteinases produced in vivo by P. aeruginosa.

• MeSH
• hemocyty enzymologie   MeSH
• hemolymfa enzymologie   MeSH
• hmyzí proteiny metabolismus   MeSH
• larva enzymologie   mikrobiologie   MeSH
• muramidasa metabolismus   MeSH
• můry enzymologie   mikrobiologie   MeSH
• Pseudomonas aeruginosa fyziologie   MeSH
• tukové těleso enzymologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hmyzí proteiny MeSH
• muramidasa MeSH

The structure of tetragonal hen egg-white lysozyme soaked in a periodate solution has been determined to a resolution of 1.8 A. Four high-occupancy periodate positions have been identified on the basis of the anomalous signal of the I atoms. The four periodates exhibit a regular rectangular arrangement on the surface of the lysozyme molecule. No similar regular arrangement was found either in lysozyme crystals soaked in other heavy-atom anions or in other structures from the Protein Data Bank. Depending on their position on the surface of the protein, the periodate ions deviate to a varying extent from ideal octahedral geometry.

• MeSH
• konformace proteinů MeSH
• krystalografie rentgenová MeSH
• kur domácí MeSH
• kyselina jodistá chemie   MeSH
• molekulární struktura MeSH
• muramidasa chemie   MeSH
• vaječné proteiny MeSH
• vodíková vazba MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina jodistá MeSH
• metaperiodate MeSH Prohlížeč
• muramidasa MeSH
• vaječné proteiny MeSH

According to research, egg quality and lysozyme content are influenced by a number of factors, which are mostly known in the case of commercial hybrids, while in breeds included in genetic resources conservation programmes, new research results in this regard are emerging. The aim of the study was to determine the effect of egg laying time and genotype of selected Polish native breeds of hens on egg quality and lysozyme content and activity in the albumen. The study material consisted of eggs collected from four strains of laying hens included in the Polish conservation programme, i.e., Green-legged Partridge (Z-11), Yellow-legged Partridge (Ż-33), Rhode Island Red (R-11) and Leghorn (H-22). At week 56, 28 eggs were randomly collected at 7:00 and 13:00 h from each breed of hen and assessed for quality. Laying time influenced certain egg quality traits. Eggs laid by hens in the morning were characterised by 1.7 g lower total weight and albumen weight, 2.4 pores/cm2 higher number of shell pores, 0.15 higher albumen pH values and 0.17 lower yolk pH values compared to those laid in the morning. The time of laying did not affect the level and activity of lysozyme in the albumen. A significant negative correlation was found between eggshell traits and albumen height, and between Haugh unit and lysozyme content and activity in the albumen. The studied egg quality traits were more influenced by genotype than by the egg-laying time.

• Klíčová slova
• egg laying time, egg quality, lysozyme, native breeds of hens,
• Publikační typ
• časopisecké články MeSH

Phage T4 lysozyme is a well folded and highly soluble protein that is widely used as an insertion tag to improve solubility and crystallization properties of poorly behaved recombinant proteins. It has been used in the fusion protein strategy to facilitate crystallization of various proteins including multiple G protein-coupled receptors, lipid kinases, or sterol binding proteins. Here, we present a structural and biochemical characterization of its novel, metal ions-binding mutant (mbT4L). We demonstrate that mbT4L can be used as a purification tag in the immobilized-metal affinity chromatography and that, in many respects, it is superior to the conventional hexahistidine tag. In addition, structural characterization of mbT4L suggests that mbT4L can be used as a purification tag compatible with X-ray crystallography.

• Klíčová slova
• crystal structure, endolysin, histidine tag, lysozyme, phage T4, protein purification,
• MeSH
• bakteriofág T4 * enzymologie   genetika   MeSH
• chromatografie afinitní metody   MeSH
• krystalografie rentgenová metody   MeSH
• muramidasa * chemie   genetika   izolace a purifikace   MeSH
• mutace * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• muramidasa * MeSH

Resistance or susceptibility of bifidobacteria to lysozyme and growth of bifidobacteria in human milk were tested. Susceptible bifidobacterial strains stopped their growth almost immediately after the addition of lysozyme (400 microg/ml), moderately susceptible strains exhibited reduced growth rate, and growth curves of resistant strains were not affected. Strains of human origin were more resistant to lysozyme than animal strains. While strains of B. bifidum grew well in human milk samples, the growth B. animalis strains was inhibited after inoculation to human milk. The resistance to lysozyme seems to be a promising criterion for the selection of new probiotic bifidobacterial strains.

• MeSH
• bakteriální léková rezistence účinky léků   MeSH
• Bifidobacterium účinky léků   růst a vývoj   MeSH
• lidé MeSH
• mateřské mléko účinky léků   mikrobiologie   MeSH
• mikrobiální testy citlivosti MeSH
• muramidasa farmakologie   MeSH
• novorozenec MeSH
• probiotika * MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hen egg lysozyme MeSH Prohlížeč
• muramidasa MeSH