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31.
Jan Kapuscinski Zbigniew Darzynkiewicz 《Journal of biomolecular structure & dynamics》2013,31(6):1485-1499
Abstract At high binding denstities acridine orange (AO) forms complexes with ds DNA which are insoluble in aqueous media. These complexes are characterized by high red- and minimal green-luminescence, 1:1 (dye/P) stoichiometry and resemble complexes of AO with ss nucleic acids. Formation of these complexes can be conveniently monitored by light scatter measurements. Light scattering properties of these complexes are believed to result from the condensation of nucleic acids induced by the cationic, intercalating ligands. The spectral and thermodynamic data provide evidence that AO (and other intercalating agents) induces denaturation of ds nucleic acids; the driving force of the denaturation is high affinity and cooperativity of binding of these ligands to ss nucleic acids. The denaturing effects of AO, adriamycin and ellipticine were confirmed by biochemical studies on accessibility of DNA bases (in complexes with these ligands) to the external probes. The denaturing properties of AO vary depending on the primary structure (sugar-and base-composition) of nucleic acids. 相似文献
32.
Halina Staniek Nicholas R. Rhodes Kristin R. Di Bona Ge Deng Sharifa T. Love Leigh Ann Pledger Jeremy Blount Emmalea Gomberg Frances Grappe Chelsea Cernosek Brittany Peoples Jane F. Rasco Zbigniew Krejpcio John B. Vincent 《Biological trace element research》2013,151(3):373-383
Diabetes results in several metabolic changes, including alterations in the transport, distribution, excretion, and accumulation of metals. While changes have been examined in several rat models of insulin resistance and diabetes, the metal ion concentrations in the tissues of Zucker lean, Zucker obese (an insulin resistance and early stage diabetes model), and Zucker diabetic fatty (ZDF, a type 2 diabetes model) have not previously been examined in detail. The concentration of Cu, Zn, Fe, Mg, and Ca were examined in the liver, kidney, heart and spleen, and Cr concentration in the liver and kidney of these rats were examined. Zucker obese rats have a reduction in the concentration of Cu, Zn, Fe, Mg in the liver compared to ZDF and/or lean Zucker rats, presumably as a result of the increased fat content of the liver of the obese rats. ZDF rats have increased concentrations of kidney Cu compared to the lean rats, while kidney Ca concentrations are increased in the Zucker obese rats. Spleen Fe concentrations are decreased in Zucker obese rats compared to the lean rats. No effects on metal concentrations in the heart were observed between the lean, obese, and ZDF rats, and no effects on Cr concentrations were identified. Cr(III) complexes have previously been shown to have beneficial effects on the signs of insulin resistance in Zucker obese and ZDF rats. The effects of daily gavage administration of chromium picolinate ([Cr(pic)3]) (1 mg?Cr/kg body mass), CrCl3 (1 mg?Cr/kg body mass), and Cr3 ([Cr3O(propionate)6(H2O)3]+) (33 μg and 1 mg?Cr/kg body mass) on metal concentrations in these tissues were examined. Treatment with CrCl3 and Cr3, but not [Cr(pic)3], at 1 mg?Cr/kg resulted in a statistically significant accumulation of Cr in the kidney of lean and obese but not ZDF rats but resulted in lowering the elevated levels of kidney Cu in ZDF rats, suggesting a beneficial effect on this symptom of type 2 diabetes. 相似文献
33.
Wiesław Malinka Piotr Świątek Małgorzata Śliwińska Bogumiła Szponar Andrzej Gamian Zbigniew Karczmarzyk Andrzej Fruziński 《Bioorganic & medicinal chemistry》2013,21(17):5282-5291
In this paper we describe synthesis, structures and some physicochemical properties of 20 isothiazolopyridines 8–13 substituted differently into an isothiazole ring as well as their in vitro antibacterial assays against Mycobacterium tuberculosis H37Rv, Mycobacterium fortuitum PCM 672 and Propionibacterium acnes PCM 2400. Compound 13a was found to be the most active derivative against M. tuberculosis H37Rv, demonstrating 100% growth inhibition of microorganisms in the primary screen (minimum inhibitory concentration [MIC] 6.25 μg/mL). Nineteen of the prepared compounds were evaluated against M. fortuitum PCM 672 and P. acnes PCM 2400 and only compounds 9 and 12d exhibited excellent activity against individual strains of microorganisms with MIC90 <1 μg/mL. The inhibitory action of the remaining isothiazolopyridines towards the tested strains of the microorganism was low, absent, or a non-linear correlation prohibited accurate determination of MIC values. Unexpectedly, seven of the remaining isothiazolopyridines tested against M. fortuitum and P. acnes stimulated growth of the microorganisms in the range 10–50% or even more (10b) under experimental conditions. 相似文献
34.
Zbigniew Zawada Martin Šafařík Eva Dvořáková Olga Janoušková Anna Březinová Ivan Stibor Karel Holada Petr Bouř Jan Hlaváček Jaroslav Šebestík 《Amino acids》2013,44(5):1279-1292
Quinacrine is a drug that is known to heal neuronal cell culture infected with prions, which are the causative agents of neurodegenerative diseases called transmissible spongiform encephalopathies. However, the drug fails when it is applied in vivo. In this work, we analyzed the reason for this failure. The drug was suggested to “covalently” modify the prion protein via an acridinyl exchange reaction. To investigate this hypothesis more closely, the acridine moiety of quinacrine was covalently attached to the thiol groups of cysteines belonging to prion-derived peptides and to the full-length prion protein. The labeled compounds were conveniently monitored by fluorescence and absorption spectroscopy in the ultraviolet and visible spectral regions. The acridine moiety demonstrated characteristic UV–vis spectrum, depending on the substituent at the C-9 position of the acridine ring. These results confirm that quinacrine almost exclusively reacts with the thiol groups present in proteins and peptides. The chemical reaction alters the prion properties and increases the concentration of the acridine moiety in the prion protein. 相似文献
35.
Anna Jarz?b Danuta Witkowska Edmund Ziomek Anna D?browska Zbigniew Szewczuk Andrzej Gamian 《PloS one》2013,8(8)
Shigella flexneri 3a is one of the five major strains of the Shigella genus responsible for dysentery, especially among children, in regions of high poverty and poor sanitation. The outer membrane proteins (OMP) of this bacterium elicit immunological responses and are considered a prime target for vaccine development. When injected into mice they elicit a protective immunological response against a lethal dose of the pathogen. The OMPs from S. flexneri 3a were isolated and resolved by two-dimension-SDS-PAGE. Two 38-kDa spots were of particular interest since in our earlier studies OMPs of such molecular mass were found to interact with umbilical cord sera. These two spots were identified as OmpC by ESI-MS/MS spectrometry. By DNA sequencing, the ompC gene from S. flexneri 3a was identical to ompC from S. flexneri 2a [Gene Bank: 24113600]. A 3D model of OmpC was built and used to predict B-cell type (discontinuous) antigenic epitopes. Six epitopes bearing the highest score were selected and the corresponding peptides were synthesized. Only the peptides representing loop V of OmpC reacted strongly with the umbilical cord serum immunoglobulins. To determine which amino acids are essential for the antigenic activity of the epitope, the loop V was scanned with a series of dodecapeptides. The peptide RYDERY was identified as a minimal sequence for the loop V epitope. Truncation at either the C- or N-terminus rendered this peptide inactive. Apart from C-terminal tyrosine, substitution of each of the remaining five amino acids with glycine, led to a precipitous loss of immunological activity. This peptide may serve as a ligand in affinity chromatography of OmpC-specific antibodies and as a component of a vaccine designed to boost human immune defenses against enterobacterial infections. 相似文献
36.
Edyta Paradowska Agnieszka Jab?ońska Miros?awa Studzińska Katarzyna Skowrońska Patrycja Suski Ma?gorzata Wi?niewska-Ligier Teresa Wo?niakowska-G?sicka Dorota Nowakowska Zuzanna Gaj Jan Wilczyński Zbigniew J. Le?nikowski 《PloS one》2016,11(4)
Toll-like receptor 9 (TLR9) recognizes non-methylated viral CpG-containing DNA and serves as a pattern recognition receptor that signals the presence of human cytomegalovirus (HCMV). Here, we present the genotype distribution of single-nucleotide polymorphisms (SNPs) of the TLR9 gene in infants and the relationship between TLR9 polymorphisms and HCMV infection. Four polymorphisms (-1237T/C, rs5743836; -1486T/C, rs187084; 1174G/A, rs352139; and 2848C/T, rs352140) in the TLR9 gene were genotyped in 72 infants with symptomatic HCMV infection and 70 healthy individuals. SNP genotyping was performed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Digested fragments were separated and identified by capillary electrophoresis. The HCMV DNA copy number was measured by a quantitative real-time PCR assay. We found an increased frequency of heterozygous genotypes TLR9 -1486T/C and 2848C/T in infants with HCMV infection compared with uninfected cases. Heterozygous variants of these two SNPs increased the risk of HCMV disease in children (P = 0.044 and P = 0.029, respectively). In infants with a mutation present in at least one allele of -1486T/C and 2848C/T SNPs, a trend towards increased risk of cytomegaly was confirmed after Bonferroni’s correction for multiple testing (Pc = 0.063). The rs352139 GG genotype showed a significantly reduced relative risk for HCMV infection (Pc = 0.006). In contrast, the -1237T/C SNP was not related to viral infection. We found no evidence for linkage disequilibrium with the four examined TLR9 SNPs. The findings suggest that the TLR9 -1486T/C and 2848C/T polymorphisms could be a genetic risk factor for the development of HCMV disease. 相似文献
37.
38.
Wojciech Lipinski Joanna Wasko Malgorzata Walczak Justyna Fraczyk Zbigniew J. Kaminski Krystian Galecki Zbigniew Draczynski Izabella Krucinska Marta Kaminska Beata Kolesinska 《化学与生物多样性》2019,16(11)
The aim of the study was the assessment of the ability of short peptides to form aggregates under physiological conditions. The dipeptides studied were derived from different aromatic amino acids (heteroaromatic peptides). Tripeptides were obtained from two distinct aromatic amino acids and cysteine or methionine residue in the C‐terminal, N‐terminal, or central position. The ability of the peptides to form fibrous aggregates under physiological conditions was evaluated using three independent methods: the Congo Red assay, the Thioflavin T assay, and microscopic examinations using normal and polarized light. Materials potentially useful for regenerative medicine were selected based on their cytotoxicity to the endothelial cell line EA.hy 926 and physicochemical properties of films formed by peptides. The required parameters of biocompatibility were fulfilled by H?PheCysTrp?OH, H?PheCysTyr?OH, H?PheTyrMet?OH, and H?TrpTyr?OH. 相似文献
39.
Szyrwiel Łukasz Shimura Mari Setner Bartosz Szewczuk Zbigniew Malec Katarzyna Malinka Wieslaw Brasun Justyna Pap József Sándor 《International journal of peptide research and therapeutics》2019,25(2):711-717
International Journal of Peptide Research and Therapeutics - Relations between structural modifiactions and SOD-like activity of four branched CuII-metallopeptides based on l-2,3-diaminopropionic... 相似文献