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91.
S.N. Khrapunov A.I. Dragan A.F. Protas G.D. Berdyshev 《International journal of biological macromolecules》1984,6(1):26-30
Using the methods of spectrophotometry, spectrofluorimetry, light scattering and gel filtration, it was shown that, at pH 5.6 and 7.4 and various ionic strengths, the histone tetramer (H3-H4)2 may have several structural states with different packing of the polypeptide chains of histones H3 and H4. Two structural changes of the tetramer (H3-H4)2 at pH 7.4 in the ranges 0.1–0.3 m and 0.7–0.9 m NaCl were observed. In the high ionic strength solution, the tetramer (H3-H4)2 had a more compact structure at pH 7.4 than at pH 5.6. At pH 3.0 destruction of the histone tetramer (H3-H4)2 and formation of non-specific aggregates took place. 相似文献
92.
Aleksandra Rašić-Marković Olivera Stanojlović Dragan Hrnčić Danijela Krstić Mirjana Čolović Veselinka Šušić Tatjana Radosavljević Dragan Djuric 《Molecular and cellular biochemistry》2009,327(1-2):39-45
Hyperhomocysteinemia is associated with various pathologies including cardiovascular disease, stroke, and cognitive dysfunctions. Systemic administration of homocysteine can trigger seizures in animals, and patients with homocystinuria suffer from epileptic seizures. Available data suggest that homocysteine can be harmful to human cells because of its metabolic conversion to homocysteine thiolactone, a reactive thioester. A number of reports have demonstrated a reduction of Na+/K+-ATPase activity in cerebral ischemia, epilepsy and neurodegeneration possibly associated with excitotoxic mechanisms. The aim of this study was to examine the in vivo effects of d,l-homocysteine and d,l-homocysteine thiolactone on Na+/K+- and Mg2+-ATPase activities in erythrocyte (RBC), brain cortex, hippocampus, and brain stem of adult male rats. Our results demonstrate a moderate inhibition of rat hippocampal Na+/K+-ATPase activity by d,l-homocysteine, which however expressed no effect on the activity of this enzyme in the cortex and brain stem. In contrast,d,l-homocysteine thiolactone strongly inhibited Na+/K+-ATPase activity in cortex, hippocampus and brain stem of rats. RBC Na+/K+-ATPase and Mg2+-ATPase activities were not affected by d,l-homocysteine, while d,l-homocysteine thiolactone inhibited only Na+/K+-ATPase activity. This study results show that homocysteine thiolactone significantly inhibits Na+/K+-ATPase activity in the cortex, hippocampus, and brain stem, which may contribute at least in part to the understanding of excitotoxic and convulsive properties of this substance. 相似文献
93.
94.
Unexpected role for granzyme K in CD56bright NK cell-mediated immunoregulation of multiple sclerosis
Jiang W Chai NR Maric D Bielekova B 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(2):781-790
Functional NK cell deficiencies are associated with autoimmune diseases, including multiple sclerosis. NK cells can promote or inhibit adaptive immunity via either cytokine production or cytotoxicity toward immature dendritic cells and activated T cells. In humans, this immunoregulatory role resides in the CD56(bright) NK cell subset, which is selectively expanded by daclizumab, a CD25-blocking Ab that suppresses multiple sclerosis-associated inflammation. The objective of this study was to investigate the molecular mechanisms underlying the cytotoxicity of NK cells toward activated T cells. We demonstrated that NK cells induce caspase-independent apoptosis that requires NK cell degranulation and causes mitochondrial dysfunction in activated T cells. Although both granzyme A and granzyme K (GrK) can mediate this form of apoptosis, quantitatively we observed preferential transfer of GrK to target cells. Consequently, gene silencing of GrK in the NK-92 cell line, which retains functional characteristics of CD56(bright) NK cells, profoundly inhibited the ability of NK-92 cells to kill activated syngeneic T cells. Finally, we demonstrated that daclizumab treatment significantly enhanced this newly defined mechanism of cytotoxicity by CD56(bright) NK cells. Our study describes the important physiological role that GrK plays in immunoregulation of adaptive immunity in humans and indicates that therapeutic exploitation of this pathway is beneficial in controlling autoimmunity. 相似文献
95.
Rasić-Marković A Krstić D Vujović Z Jakovljevic V Stanojlović O Hrncić D Djurić D Loncar-Stevanović H 《Molecular and cellular biochemistry》2008,308(1-2):111-116
Alcohol intake is associated with numerous degenerative disorders, and the detrimental effects of alcohol may be due to its
influence on plasma membrane and cellular transport systems. The aim of the present study was to compare in vitro and in vivo
effects of ethanol on rabbit erythrocyte ATPase activities and correlate them with ethanol-induced oxidative stress. Age-matched
male rabbits were given 5% ethanol in 2% sucrose solution, for 6 weeks ad libitum; control animals were given tap water. Daily
intake of ethanol was 5 g/kg body weight; this experimental regimen resulted in an average serum ethanol concentration of
16.77 ± 2.00 mM/l. After this period, blood was collected, serum ethanol concentration was determined and erythrocyte membranes
were prepared according to the method of Post et al. Activities of Na+/K+- and Mg2+-ATPases were determined. Thiobarbituric acid-reactive substance (TBARS) assay was used to detect levels of lipid peroxidation,
a major indicator of oxidative stress. In vitro ethanol inhibits both Na+/K+-ATPase and Mg2+-ATPase, but Na+/K+-ATPase is more sensitive to the ethanol-induced inhibition. Increasing concentration of ethanol increased TBARS production,
but significant difference was attained only at 5 and 12.5 mM of ethanol. Chronic ethanol consumption induced significant
increase in Na+/K+- and Mg2+-ATPase activity, and TBARS production. Our results suggest that increased ATPase activity induced by chronic ethanol consumption
is due to oxidative, induced modification of membrane phospholipids and proteins, which are responsible for inhibition of
ATPase activity. Increased production of TBARS induced by in vitro exposure to ethanol is not the only factor that influences
ATPases activity. Further research is needed to elucidate this relationship. 相似文献
96.
97.
Peters BA Kan Z Sebisanovic D Pujara K Wang Z Hong P Chow B Stinson J Carlton VE Pham TQ Stern H Waring P Hillan KJ Eberhard DA de Sauvage F Zheng J Faham M Seshagiri S 《Nature methods》2007,4(9):713-715
The discovery of somatic mutations in cancer tissue is extremely laborious, time-consuming and costly. In an evaluation comparing mismatch repair detection (MRD) against Sanger sequencing for somatic-mutation detection, we found that MRD had a specificity of 96% and a sensitivity of 92%. Our results showed that MRD is a robust and cost-effective alternative to Sanger sequencing for identifying somatic mutations in human tumors. 相似文献
98.
Laura K. Schnackenberg Yvonne P. Dragan Michael D. Reily Donald G. Robertson Richard D. Beger 《Metabolomics : Official journal of the Metabolomic Society》2007,3(2):87-100
Single low and high doses of several compounds with known renal toxic effects (para-aminophenol, puromycin aminonucleoside,
sodium chromate, and hexachlorobutadiene,) or known liver toxic effects (galactosamine, allyl alcohol, and thioacetamide)
were administered to male Wistar rats in groups of 4 or 8 for each compound. Predose urine samples (Day 0) and samples from
post-dosing (Days 1–4) were collected for each rat and monitored by 1D 1H NMR. Principal component analysis (PCA) of the NMR spectra was used to investigate differences between dose levels for each
compound individually. The findings from PCA at both dose levels for each compound were examined in the context of the corresponding
clinical chemistry and pathology data collected during the study. The PCA clustering of NMR spectra from rats dosed with each
individual compound were shown to be associated with the measured levels of creatinine, BUN, AST, ALT and histopathology findings.
Finally, scaled-to-maximum, aligned, and reduced trajectories (SMART) analysis was applied to compare the temporal metabolic
trajectories obtained for each animal at each dose level of the administered compounds. By day 4, the SMART trajectories for
allyl alcohol and hexachlorobutadiene had returned to predose levels indicating a recovery response, however, the high dose
SMART trajectories for para-aminophenol, puromycin aminonucleoside, sodium chromate, and galactosamine did not appear to return
to predose levels indicating a prolonged toxic effect. 相似文献
99.
Perovic D Tiffin P Douchkov D Bäumlein H Graner A 《Functional & integrative genomics》2007,7(2):169-179
Recent genomic projects reveal that about half of the gene repertoire in plant genomes is made up by multigene families. In
this paper, a set of structural and phylogenetic analyses have been applied to compare the differently sized nicotianamine
synthase (NAS) gene families in barley and rice. Nicotianamine acts as a chelator of iron and other heavy metals and plays
a key role in uptake, phloem transport and cytoplasmic distribution of iron, challenging efforts for the breeding of iron-efficient
crop plants. Nine barley NAS genes have been mapped, and co-linearity of flanking genes in barley and rice was determined.
The combined analyses reveal that the NAS multigene family members in barley originated through at least one duplication event
that occurred before the divergence of rice and barley. Additional duplications appear to have occurred within each of the
species. Although we detected no evidence for positive selection of recently duplicated genes within species, codon-based
tests revealed evidence for positive selection having contributed to the divergence of some amino acids. The integrated comparative
and phylogenetic analysis improved our current view of NAS gene family evolution, might facilitate the functional characterization
of individual members and is applicable to other multigene families.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
100.
Djordjevic DZ Cubrilo DG Barudzic NS Vuletic MS Zivkovic VI Nesic M Radovanovic D Djuric DM Jakovljevic VLj 《General physiology and biophysics》2012,31(2):211-219
The aims of our study were to assess the redox state of adolescent athletes and non-athletes both at rest and after acute exposure to physical load and to find relations between parameters of redox state and morphofunctional characteristics of subjects. 58 young handball players and 37 non-athletes were subjected to body composition analysis, measuring of maximal oxygen consumption and blood sampling immediately before and after a maximal progressive exercise test. At rest, athletes had significantly higher superoxide dismutase (SOD) and catalase (CAT) activity, higher levels of glutathione (GSH) and nitric oxide (NO) and lower levels of lipid peroxidation (TBARS) compared with non-athletes. A maximal exercise test induced statistically significant rise of superoxide anion radical (O2-), hydrogen peroxide (H2O2) and NO levels in non-athletes, while TBARS levels decreased. Athletes experienced the fall in NO levels and the fall in CAT activity. After exercise, athletes had significantly lower levels of O2- compared with non-athletes. Two way repeated measures ANOVA showed that the response of O2-, NO and TBARS to the exercise test was dependent on the sports engagement (training experience) of subjects. Significant correlations between morphofunctional and redox parameters were found. These results suggest that physical fitness affects redox homeostasis. 相似文献