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1.
Dokl Biochem Biophys ; 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39283554

RESUMO

The objective of this work was to study the expression of the TBX21, RORC, GATA3, NFKB1, MAPK8, and STAT3 genes responsible for the regulation of the differentiation of various T-helper subpopulations in individuals chronically exposed to radiation. The object of the study was peripheral blood cells obtained from 120 persons chronically exposed to radiation in a wide range of doses on the Techa River. The mean cumulative absorbed dose to red bone marrow in the examined exposed individuals was 742.7 ± 78.6 mGy (dose range, 73.5-3516.1 mGy); in the comparison group, 17.4 ± 2.2 mGy (dose range, 0.0-55.5 mGy). The subpopulation composition of T-helpers (Th1, Th2, and Th17) was analyzed by flow cytofluorometry. The relative mRNA content of the TBX21, RORC, GATA3, NFKB1, MAPK8, and STAT3 genes was estimated by real-time PCR. The study made it possible to note a decrease in the relative number of T-helpers 2 in the populations of T-helpers of the central memory in the group of chronically exposed persons compared to the comparison group. In the population of T-helpers of the central memory, a statistically significant increase in the relative number of T-helpers 1 was shown, depending on the accumulated absorbed dose to red bone marrow. No changes in mRNA expression of the studied genes were observed. The analysis of the correlation between the expression of GATA3, MAPK8, STAT3, RORC, and TBX21 mRNA and the relative number of cells in subpopulations of T-helper types 1, 2, and 17 in the examined people did not reveal statistically significant patterns.

2.
Ter Arkh ; 95(11): 958-964, 2023 Dec 22.
Artigo em Russo | MEDLINE | ID: mdl-38158952

RESUMO

AIM: The search for etiopathogenetic agents to prevent the development of severe and extremely severe COVID-19 remains relevant. A placebo-controlled randomized clinical trial was conducted to evaluate the efficacy and safety of the antibody-based biological drug (Raphamin). MATERIALS AND METHODS: 785 outpatients 18-75 y.o. with laboratory confirmed mild COVID-19 were included within 24 hours from the disease onset. 771 patients were randomized to the group Raphamin (n=382) and the Placebo group (n=389). The study drug/placebo was prescribed for 5 days. The rate of progression to a more severe degree of COVID-19 by day 28 as well as the time to sustained clinical recovery and the frequency of hospitalization were evaluated. Safety was assessed taking into account adverse events, vital signs and laboratory parameters. RESULTS: The number of cases of progression to a more severe degree of COVID-19 in participants receiving Raphamin was 59 (15.5%) [52 (14.6%)] versus placebo - 89 (22.9%) [85 (23.7%)], ITT and [PP] analysis data are presented. The odds ratio between groups was OR=0.6157 [OR=0.5494], 95% confidence interval 0.4276-0.8866 [0.3750-0.8048], which meant a reduction in the chance of progression to a more severe degree by 38.4% [45.1%] or 1.48 [1.62] times; p=0.0088 [p=0.0019]. The time to sustained recovery in the Raphamin group was 4.5±2.4 [4.6±2.4] days, versus placebo - 5.8±4.7 [6.0±4.8] days; p=0.0025 [p=0.0036]. No adverse events with a certain relationship were registered. CONCLUSION: Raphamin reduces the risk of progression to a more severe degree of the COVID-19 and significantly shortens the duration of clinical symptoms.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Resultado do Tratamento , Hospitalização , Método Duplo-Cego
3.
Mol Biol (Mosk) ; 56(6): 1072-1082, 2022.
Artigo em Russo | MEDLINE | ID: mdl-36475490

RESUMO

Methylation of the CpG islands of gene promoter regions is the most common epigenetic modification involved in the regulation of gene expression. A number of studies have shown that ionizing radiation can cause both hyper- and hypomethylation of DNA. Aberrant methylation affects cellular processes and can lead to the development of various pathological states. In the literature, there are few studies on the methylation status of human DNA a long time after radiation exposure. Here, the methylation level of CpG islands of the promoter regions of apoptosis genes (BCL2, ATM, MDM2, CDKN1A, STAT3, and NFKB1), and also its influence on apoptosis of peripheral blood lymphocytes in chronically exposed persons were studied. Residents of the South Ural region who were chronically exposed to radiation (after discharges of radioactive wastes into the Techa river by the "Mayak Production Association" in 1949-1956) were included in the study. It was established that the proportion of individuals with hypermethylated BCL2 gene promoter among the exposed people was statistically significantly higher than in the control group. The percentage of methylation of the ATM gene promoter weakly positively correlated with dose and age characteristics. Differences in the frequency of lymphocyte apoptosis in exposed individuals with a hypo- or hypermethylated ATM gene promoter were also established. The data indicate that, in the long-term, after chronic low intensity radiation exposure at low and medium doses, epigenetic modifications of the genome occur, which are manifested as changes in methylation of promoter regions of BCL2 and ATM genes.


Assuntos
Apoptose , Linfócitos , Humanos , Apoptose/genética , DNA , Proteínas Proto-Oncogênicas c-bcl-2/genética
4.
Ter Arkh ; 94(1): 83-93, 2022 Jan 15.
Artigo em Russo | MEDLINE | ID: mdl-36286922

RESUMO

AIM: To evaluate the efficacy and safety of Raphamin, containing technologically processed affinity-purified antibodies to interferon , CD4 receptor, 1 domain of the major histocompatibility complex class II and 2 microglobulin major histocompatibility complex class I in the treatment of acute respiratory viral infection (ARVI), including influenza, in adults. MATERIALS AND METHODS: 240 patients 1870 years old with ARVI were included in a phase III (20192020), randomized, double-blind, placebo-controlled trial. Pregnant women, patients with suspected bacterial infections were excluded from the study. Raphamin/placebo was prescribed for 5 days within 24 hours of the illness onset. Primary endpoint was a time to resolution of ARVI (Polymerase chain reaction PCR-confirmed). Additionally, the severity of ARVI, proportion of patients with ARVI resolution/worsening/complications, frequency of antipyretics prescription, and time to resolution of symptoms of ARVI (including PCR non confirmed) were assessed. RESULTS: The average time to resolution of ARVI (PCR-confirmed) was 4.11.9 [4.01.9] and 5.02.5 [5.02.5] days in the Raphamin/placebo groups (ITT and [PP] analysis, р=0.0155 and [р=0.0114], respectively). The duration of ARVI decreased by 0.892.23 [0.932.25] days. Superiority of Raphamin was shown during therapy period according to the ARVI resolution criterion (р=0.0014 [р=0.0005]). There were no statistically significant difference in the severity of ARVI and frequency of antipyretics prescription. The proportion of patients with worsening/complications was 0 [0]% and 2.5 [2.8]% in the Raphamin and placebo groups, respectively. Favorable safety profile of Raphamin (including the incidence and severity of adverse events) and high compliance were shown. CONCLUSION: Raphamin promotes significant decrease, practically by a day, the duration of ARVI, including influenza.


Assuntos
Antipiréticos , Influenza Humana , Infecções Respiratórias , Viroses , Adulto , Humanos , Feminino , Gravidez , Antivirais/efeitos adversos , Influenza Humana/tratamento farmacológico , Influenza Humana/epidemiologia , Antipiréticos/uso terapêutico , Antígenos CD4/uso terapêutico , Viroses/tratamento farmacológico , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/epidemiologia , Método Duplo-Cego , Anticorpos , Interferons/uso terapêutico , Resultado do Tratamento
5.
Food Chem Toxicol ; 164: 112999, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35427705

RESUMO

Consumer spray products release aerosols that can potentially be inhaled and reach the deep parts of the lungs. A thin layer of liquid, containing a mixture of proteins and lipids known as lung surfactant, coats the alveoli. Inhibition of lung surfactant function can lead to acute loss of lung function. We focused on two groups of spray products; 8 cleaning and 13 impregnation products, and in the context of risk assessment, used an in vitro method for assessing inhibition of lung surfactant function. Original spray-cans were used to generate aerosols to measure aerodynamic particle size distribution. We recreated a real-life exposure scenario to estimate the alveolar deposited dose. Most impregnation products inhibited lung surfactant function at the lowest aerosolization rate, whereas only two cleaning products inhibited function at the highest rates. We used inhibitory dose and estimated alveolar deposition to calculate the margin of safety (MoS). The MoS for the inhibitory products was ≤1 for the impregnation products, while much larger for the cleaning products (>880). This risk assessment focused on the risk of lung surfactant function disruption and provides knowledge on an endpoint of lung toxicity that is not investigated by the currently available OECD test guidelines.


Assuntos
Exposição por Inalação , Surfactantes Pulmonares , Aerossóis/toxicidade , Excipientes , Exposição por Inalação/efeitos adversos , Exposição por Inalação/análise , Pulmão/metabolismo , Tamanho da Partícula , Surfactantes Pulmonares/metabolismo , Surfactantes Pulmonares/toxicidade , Medição de Risco , Tensoativos/toxicidade
6.
Vavilovskii Zhurnal Genet Selektsii ; 26(1): 50-58, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35342850

RESUMO

Transcriptional activity of genes involved in maintaining genetic homeostasis (genes for repair, cell cycle and apoptosis: TP53, MDM2, ATM, BAX, BCL-2, CDKN1A, OGG1, XPC, PADI4, MAPK8, NF-KB1, STAT3, GATA3) was studied in chronically exposed persons with an increased intensity of early and late stages of apoptosis and necrosis of peripheral blood lymphocytes. The object of this study was peripheral blood mononuclear cells obtained from 132 chronically exposed residents of the Techa riverside villages. The mean accumulated dose to red bone marrow was 426.4 ± 48.2 mGy (1.3-2930.0 mGy), to thymus and peripheral immune organs, 58.9 ± 7.9 mGy (0.1-489.0 mGy). The study was performed more than 60 years after the onset of exposure, the average age of exposed persons was 68 ± 0.6 years (55-86 years). The study of apoptotic and necrotic death of peripheral blood lymphocytes was based on the presence of phosphatidylserine on the cell membrane surface, as well as on its permeability for DNA-intercalating dye. Evaluation of the relative content of mRNA genes for repair, cell cycle, and apoptosis was carried out using real-time PCR. An increased relative content of PADI4 gene mRNA was registered in the group of chronically exposed persons with the increased intensity of early apoptosis (p = 0.006). Modulation of the relative content of mRNA of the TP53 (p = 0.013) and BCL-2 (p = 0.021) genes was detected in the group of chronically exposed individuals with the increased intensity of the late stage of apoptosis. A statistically signif icant increase in the transcriptional activity of the TP53 gene was observed in the group of chronically exposed persons with the increased intensity of peripheral blood lymphocyte necrosis in the long-term period (p = 0.015). In the course of the study it was noted that exposed people with increased intensity of apoptosis, f irst of all, demonstrate changes in the transcriptional activity of apoptotic genes. These data are consistent with current views on the activation of programmed cell death.

7.
Vopr Pitan ; 89(5): 44-58, 2020.
Artigo em Russo | MEDLINE | ID: mdl-33211917

RESUMO

Mesenterial hypoperfusion is one of the main pathogenetic factors of necrotizing enterocolitis (NEC) in infants with ductus-dependent congenital heart diseases. NEC in infants undergoing congenital heart surgery increases mortality and length of hospital stay. NEC is also associated with adverse neurodevelopmental outcome. Optimization of enteral feeding can reduce the risk of gastrointestinal complications. NEC risk factors in infants with congenital heart are of special interest in the literature. This article discusses criteria for enteral feeding initiation and increasing preoperatively and after heart surgery. Enteral feeding protocols of leading cardiac surgical centers are reviewed. Practices to provide high energy and nutrient consumption in infants with congenital heart disease are described.


Assuntos
Nutrição Enteral , Enterocolite Necrosante , Cardiopatias Congênitas , Enterocolite Necrosante/etiologia , Enterocolite Necrosante/prevenção & controle , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/cirurgia , Humanos , Lactente , Recém-Nascido
8.
Vavilovskii Zhurnal Genet Selektsii ; 24(4): 399-406, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33659823

RESUMO

It is known that ionizing radiation influences the expression of the genes that play a key role in the mechanisms of maintaining the stability of cellular homeostasis. As a rule, changes in the transcriptome of an exposed cell occur within the first 24 hours following radiation exposure. And it predetermines early response in the case of genome damage. Later on modulations in gene transcription activity are also possible and could result in a carcinogenic effect. However, in order to find the role of exogenous factors (ionizing radiation), it is also necessary to take into account the contribution of endogenous factors that are able to modify gene transcription activity. This is especially important for long after the onset of radiation exposure. Single nucleotide polymorphisms located in regulatory regions of the genes may belong to this group of factors. The objective of the current study was to analyze the influence of ionizing radiation on the transcription activity of the STAT3, GATA3, NFkB1, PADI4 genes, which regulate proliferation and differentiation of immune competent human cells; and to assess the potential influence of single nucleotide polymorphisms located in regulatory regions of the genes on the amount of mRNA. The study involved people who had been chronically exposed due to releases of radioactive waste into the Techa River. It was observed that 60 years after the onset of radiation exposure changes in the transcription activity of the NFkB1 and PADI4 genes were registered in people with cumulative doses to RBM within the range 78-3510 mGy. In people who had been chronically exposed, the effect of allelic variations in rs1053023, rs4143094, rs28362491, rs874881 on the level of mRNAs of the STAT3, GATA3, PADI4, NFkB1 genes has not been established.

9.
Klin Med (Mosk) ; 95(3): 238-44, 2017.
Artigo em Russo | MEDLINE | ID: mdl-30303349

RESUMO

Aim: To determine content of mononuclear ells (MNC) in peripheral blood of patients with coronary heart disease (CHD) and factors responsible for their functional state and cytokine production. Materials and methods: Concentration of proteinkinases JNK1/2, ERK1/2, MAPK38, AKT1, JAK2, FAK, AMPK, p70S6K, STAT3, STAT5B and STAT6 was determined in MNC lysate by immune-enzyme assay. Interleukin 1ß, 2, 4 and y-interferon levels were measured in blood sera. Results: In patients with angina of effort and unstable angina, the JNK level was 59,8% and 53,1% higher than the normal one respectively (р=0,013) and (р=0,012). The level of the nuclear transcription factor was 26,9% (р=0,015) and 27,9% (р=0,017), JAK2 31,5% (р=0,022) and 48,6% (р=0,018), STAT3 49,6% (р=0,025) and 55,3% (р=0,02), STAT5B 21,5% (р=0,018) and 30,2% (р=0,011) lower. These changes were associated with a 13,1% (р=0,047) and 51,4% (р=0,019) rise in the STAT6 level, 30,1% (р=0,025) and 79,4% (р=0,003) FAK level, 7,6% (р=0,09) and 15,2% (р=0,039) АКТ1 level, 65,3 (р=0,02) and 76,2% (р=0,017) p70S6K level. Conclusion: Results of the study suggest persistent pro-inflammatory activation of whole blood cells in CHD patients due to enhanced levels of IL-1 and IL-2, components of the MAPK/SAPK signal pathway in MNC and decreased STAT3 level determining cell sensitivity to IL-10. The elevated intracellular level of ERK and JNK us responsible for high responsiveness of MNC to pro-inflammatory cytokines.


Assuntos
Doença da Artéria Coronariana , Fatores Imunológicos , Leucócitos Mononucleares/imunologia , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico , Correlação de Dados , Feminino , Humanos , Fatores Imunológicos/classificação , Fatores Imunológicos/metabolismo , Inflamação/imunologia , Masculino , Pessoa de Meia-Idade , Gravidade do Paciente , Transdução de Sinais
10.
Bull Exp Biol Med ; 161(2): 296-9, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27388631

RESUMO

The possibility of using mesoporous silicon nanoparticles as amplifiers (sensitizers) of therapeutic ultrasonic exposure were studied experimentally in vitro and in vivo. The combination of nanoparticles and ultrasound led to a significant inhibition of Hep-2 cancer cell proliferation and Lewis lung carcinoma growth in mice. These results indicated good prospects of using silicon nanoparticles as sensitizers for sonodynamic therapy of tumors.


Assuntos
Antineoplásicos/administração & dosagem , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Silício/administração & dosagem , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Masculino , Camundongos Endogâmicos CBA , Nanopartículas/química , Transplante de Neoplasias , Silício/química , Ondas Ultrassônicas
11.
Bull Exp Biol Med ; 161(1): 88-91, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27270934

RESUMO

Dynamic light scattering method or laser correlation spectroscopy was applied to evaluation of the size of viruses. We measured correlation functions of the light scattered by human immunodeficiency viruses (HIV) and hepatitis A viruses (HAV) and found that size of HIV-1 (subtype A and B) and HAV virions were 104 nm and 28 nm, respectively. Comparison of these findings with electron microscopy data for fixed samples of the same viruses showed good agreement of the results.


Assuntos
HIV-1/ultraestrutura , Vírus da Hepatite A/ultraestrutura , Linhagem Celular , Difusão Dinâmica da Luz , Humanos , Lasers , Microscopia Eletrônica , Tamanho da Partícula , Análise Espectral
12.
Biofizika ; 61(2): 255-8, 2016.
Artigo em Russo | MEDLINE | ID: mdl-27192826

RESUMO

A model describing the process of dissociation of hydrogen bonding in water clusters when irradiated by electromagnetic field in the microwave range is suggested. The model is also applicable for the case of rupture of the covalent bond of the water molecule cluster. If the energy absorption occurs at the interface of water and polymer clusters (e.g., DNA, chitosan), degradation of the polymer chain is possible.


Assuntos
Quitosana/química , DNA/química , Ligação de Hidrogênio/efeitos da radiação , Micro-Ondas , Quitosana/efeitos da radiação , DNA/efeitos da radiação , Campos Eletromagnéticos , Água/química
14.
Zh Evol Biokhim Fiziol ; 47(4): 278-82, 2011.
Artigo em Russo | MEDLINE | ID: mdl-21938909

RESUMO

Accumulation of Na+ and K+ ions in oocytes of the river lamprey Lampetra fluviatilis and their transport across the plasma membrane is realized by two main mechanisms--Na,K-pump and Na,K,Cl-cotransport. At the prespawning period from December to May the intracellular Na+ concentration was observed to increase from 10 to 25 mM and the K+ concentration--from 28 to 45 mM. Results obtained on isolated oocytes with aid of 204Tl radioactive label have shown that contributions of the Na,K-pump and Na,K,Cl-cotransport to potassium accumulations were close until March. In spring, the total K+ inflow almost doubled owing to activation of the Na,K-pump, whereas contribution of Na,K,Cl-cotransport did not change. It seems that an increase of the intracellular content of the main inorganic cations in oocytes resulted in parallel activation of the Na,K-pump and probably of Na/H-exchange. The biological significance of activation of these mechanisms of ion transport at the prespawning period might be due to a necessity of accumulation of Na+ and K+ ions in concentrations optimal for subsequent embryonic development.


Assuntos
Lampreias/metabolismo , Oócitos/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Animais , Transporte Biológico Ativo , Membrana Celular/metabolismo , Feminino , Transporte de Íons , Lampreias/fisiologia , Oócitos/enzimologia , Reprodução/fisiologia , Rios , Estações do Ano , Simportadores de Cloreto de Sódio-Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Radioisótopos de Tálio
15.
Vopr Virusol ; 55(3): 44-7, 2010.
Artigo em Russo | MEDLINE | ID: mdl-20608082

RESUMO

The study has shown the efficiency of a competitive ELISA (C-ELISA) variant or an indirect ELISA (I-ELUSA) in the detection of antibodies to swine vesicular disease virus (SVDV) versus traditional assays, such as a microneutralization test, a blocking ELIDA test, and a the reference test Ceditest SVDV (Cedi-Diagnostics B.V., Netherlands). Specific antibodies in the pig sera could be detected by C-ELISA on days 4-5 and by I-ELISA on day 6 after experimental SVDV infection. Specific antibodies were detected in a contact pig 11 days after the beginning of the experiment.


Assuntos
Anticorpos Antivirais/sangue , Enterovirus Humano B/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Técnica Direta de Fluorescência para Anticorpo , Técnica Indireta de Fluorescência para Anticorpo , Doença Vesicular Suína/diagnóstico , Animais , Enterovirus Humano B/imunologia , Suínos , Doença Vesicular Suína/sangue
16.
Gig Sanit ; (6): 35-7, 2010.
Artigo em Russo | MEDLINE | ID: mdl-21381361

RESUMO

Perspectives for nature protection and energy-saving, by using blue-green algae, are discussed. Utilization of their phyto biomass for biogas manufacture will lead to the environmental normalization of the Transdniestria and allow one to have about 19,000,000 m3 of methane only from the water area of only one Kremenchug water basin each vegetative period (70 days).


Assuntos
Biocombustíveis , Reatores Biológicos , Biotecnologia/métodos , Cianobactérias , Humanos , Fotossíntese
17.
J Bacteriol ; 190(8): 3088-92, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18281402

RESUMO

Highly conserved amino acid residues in region 2 of the RNA polymerase sigma subunit are known to participate in promoter recognition and opening. We demonstrated that nonconserved residues in this region collectively determine lineage-specific differences in the temperature of promoter opening.


Assuntos
Substituição de Aminoácidos/genética , Regiões Promotoras Genéticas , Fator sigma/genética , Fator sigma/metabolismo , Temperatura , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Deinococcus/enzimologia , Deinococcus/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Thermus/enzimologia , Thermus/genética , Transcrição Gênica
19.
Klin Med (Mosk) ; 84(2): 28-32, 2006.
Artigo em Russo | MEDLINE | ID: mdl-16613002

RESUMO

The subjects of the study were 64 patients with coronary heart disease, and 38 healthy individuals. In order to evaluate the degree of endothelial dysfunction (ED) reactive hyperemia test was performed; the degree of the relative increase of the brachial artery diameter, and the level of desquamated endothelial cells circulating in blood (CEC) were used as criteria of this dysfunction. Only in 6.5% of the controls signs of ED (endothelium-dependent vasodilatation (EDVD) less than 10% and the number of CEC being greater than 5 in the field of vision) was noted. In group II the signs of ED were registered in 40% of patients, in group III--in 59% of patients (p < 0.05). In patients with no standard risk factors or with only one of them, both tests revealed no signs of ED, while the presence of 4 or more risk factors lead to a 6-fold increase of the relative frequency of ED.


Assuntos
Doença das Coronárias/etiologia , Endotélio Vascular/fisiopatologia , Artéria Braquial/fisiopatologia , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Doença das Coronárias/sangue , Ecocardiografia , Eletrocardiografia , Endotélio Vascular/citologia , Humanos , Hipertensão/complicações , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Fatores de Risco , Fumar/efeitos adversos , Triglicerídeos/sangue , Vasodilatação/fisiologia
20.
Biochemistry (Mosc) ; 70(11): 1227-30, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16336181

RESUMO

The interaction of RNA polymerases from Escherichia coli and Thermus aquaticus with lacUV5 promoter was studied at various temperatures. Using DNA-protein cross-linking induced by formaldehyde, it was demonstrated that each RNA polymerase formed a unique pattern of contacts with DNA in the open promoter complex. In the case of E. coli RNA polymerase, beta and sigma subunits were involved into formation of cross-links with the promoter, whereas in the case of T. aquaticus RNA polymerase its beta subunit formed the cross-links with the promoter. A cross-linking pattern in promoter complexes of a hybrid holoenzyme comprised of the core-enzyme of E. coli and sigma subunit of T. aquaticus was similar to that of the E. coli holoenzyme. This suggests that DNA-protein contacts in the promoter complex are primarily determined by the core-enzyme of RNA polymerase. However, temperature-dependent behavior of contact formation is determined by the sigma subunit. Results of the present study indicate that the method of formaldehyde cross-linking can be employed for elucidation of differences in the structure of promoter complexes of RNA polymerases from various bacteria.


Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/enzimologia , Óperon Lac , Regiões Promotoras Genéticas , Thermus/enzimologia
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