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1.
Salud colect ; 11(1): 115-128, ene.-mar. 2015.
Artigo em Espanhol | LILACS | ID: lil-746688

RESUMO

Los antipsicóticos no parecen revertir las causas de la esquizofrenia y, aunque son fármacos que pueden aliviar los síntomas a corto y mediano plazo, a largo plazo pueden no ser beneficiosos e incluso ser contraproducentes. Su empleo debería limitarse a situaciones agudas con agitación y tensión incapacitante. Presentan considerables efectos adversos y, ante la negativa de una persona a seguir tomándolos, adoptar una estrategia de reducción de daños apoyando y supervisando la retirada puede ser preferible a la coerción. Existen alternativas a los neurolépticos. Los prescriptores deberían estar más atentos y considerar las valoraciones que los usuarios hacen de sus efectos. El apego a las guías de tratamiento es escaso, seguramente por basarse en ensayos clinicos de calidad deficente, que deben mejorar y prolongarse en el tiempo. La raíz del problema probablemente se encuentra en la tautología sobre la etiología y naturaleza biológica de lo que llaman esquizofrenia, que realmente no parece ser más que un constructo ideológico-comercial.


Antipsychotic drugs do not appear to reverse the causes of schizophrenia, and although they can relieve symptoms in the short to medium term, in the long term they may not be beneficial and could even be counterproductive. Their use should be limited to acute situations in which agitation and tension is disabling. The drugs have significant adverse effects, and given the refusal of a person to continue taking them, a harm reduction strategy to support and monitor the withdrawal may be preferable to coercion. There are alternatives to neuroleptics. Prescribers should be more vigilant and consider the assessments of users regarding the drugs' effects. Adherence to treatment guidelines is low, probably because the guidelines are based on clinical trials of deficient quality which consequently should be improved and extended over a greater period of time. The root of the problem is likely the tautology on the etiology and biological nature of what is known as schizophrenia, which in fact does not seem to be more than a commercial and ideological construct.


Assuntos
Proteínas de Bactérias/química , Biofísica/métodos , Proteínas de Ligação a DNA/química , Microscopia de Força Atômica/métodos , Ligação de Hidrogênio , Cinética , Modelos Moleculares , Modelos Estatísticos , Método de Monte Carlo , Peptostreptococcus/metabolismo , Conformação Proteica , Desnaturação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas/química , Estresse Mecânico , Temperatura , Fatores de Tempo , Ubiquitina/química
3.
Rev. bras. parasitol. vet ; 23(4): 456-462, Oct-Dec/2014. tab, graf
Artigo em Inglês | LILACS, SES-SP | ID: lil-731255

RESUMO

This study aimed to investigate the occurrence of Lutzomyia longipalpis and also the canine visceral leishmaniasis (CVL) in a rural area of Ilha Solteira, state of São Paulo. Blood samples were collected from 32 dogs from different rural properties (small farms) and were analyzed by ELISA and the indirect immunofluorescence antibody test (IFAT) in order to diagnose CVL. From these serological tests, 31.25% of the dogs were positive for CVL and these were distributed in 66.7% (8/12) of the rural properties, which were positive for L. longipalpis. CDC (Center for Disease Control and Prevention) light traps were installed in 12 properties (one per property) and insects were caught on three consecutive days per month for one year. L. longipalpis was present on 100% of the rural properties visited, at least once during the twelve-month interval, totaling 64 males and 25 females. The insects were more numerous after the peak of the rain, but the association between prevalence of peridomestic vectors and the climatic data (precipitation, relative air humidity and temperature) and the occurrences of CVL among dogs on each rural property were not statistical significant (p <0.05). However, the occurrence of CVL cases in dogs and the presence of L. longipalpis indicate that more attention is necessairy for the control of this disease in the rural area studied.


O objetivo desse trabalho foi o estudo da prevalência de Lutzomyia longipalpis e da leishmaniose visceral canina (LVC) em uma área rural do município de Ilha Solteira do estado de São Paulo. Amostras de sangue foram coletadas de 32 cães provenientes de pequenas propriedades rurais e analisadas por meio dos métodos sorológicos ELISA (imunoensaio enzimático indireto) e RIFI (reação de imunofluorescência indireta) para o diagnóstico da LVC. Pelos exames sorológicos, dos 32 cães avaliados, 31,25% foram diagnosticados positivos para LVC, os quais estavam diostribuídos em 66,67% (8/12) das propriedades positivas para Lutzomyia longipalpis. Armadilhas luminosas do tipo CDC (Center for Disease Control and Prevention) foram instaladas em 12 propriedades, sendo uma por propriedade, e as coletas dos insetos foram realizadas três dias consecutivos a cada mês, durante um ano. O inseto L. longipalpis foi encontrado em 100% das propriedades visitadas, pelo menos uma vez no ano, totalizando 65 machos e 25 fêmeas. A maior quantidade de insetos foi observada principalmente após a ocorrência dos maiores picos de precipitação pluvial, mas a associação entre a prevalência dos vetores peridomiciliares e os dados climáticos (precipitação, umidade relativa do ar e temperatura) assim como a ocorrência da CVL em cães em cada propriedade não foi estatisticamente significante (p<0.05). No entanto, alerta-se que pela presença dos casos de LVC nos cães amostrados e também de L. longipalpis, maior atenção deve ser dada durante as investigações epidemiológicas para o controle dessa doença nessa área rural estudada.


Assuntos
Proteínas de Ligação a DNA/fisiologia , RNA Polimerases Dirigidas por DNA/química , Escherichia coli/enzimologia , Fator sigma/química , Fatores de Transcrição/fisiologia , Proteínas Virais/fisiologia , DNA , Proteínas de Ligação a DNA/química , RNA Polimerases Dirigidas por DNA/fisiologia , Fator sigma/fisiologia , Fatores de Transcrição/química , Transcrição Gênica , Técnicas do Sistema de Duplo-Híbrido , Proteínas Virais/química
4.
Yonsei Medical Journal ; : 772-777, 2013.
Artigo em Inglês | WPRIM | ID: wpr-211908

RESUMO

PURPOSE: SNF2L belongs to Imitation Switch family and plays an essential role in neural tissues and gonads. In our previous studies, we have demonstrated that the basal transcription of human SNF2L gene is regulated by two cis-elements, cAMP response element (CRE)- and Sp1-binding sites. Recent studies suggested that cyclic adenosine monophosphate (cAMP) stimulation significantly up-regulated SNF2L expression in ovarian granulose cells. These data suggested that protein kinase-mediated signal pathways might also regulate SNF2L expression in neural cells. We therefore investigated the effects of agents that activate protein kinases A on SNF2L gene expression in neural cells. MATERIALS AND METHODS: To increase intracellular cAMP levels, all neural cells were treated with forskolin and dbcAMP, two cAMP response activators. We exmined the effects of cAMP on the promoter activity of human SNF2L gene by luciferase reporter gene assays, and further examined the effects of cAMP on endogenous SNF2L mRNA levels by qPCR. RESULTS: Transient expression of a luciferase fusion gene under the control of the SNF2L promoter was significantly increased by treatment of rat primary neurons with forskolin or dbcAMP, but not PC12, C6 and SH-SY5Y cells. Consistently, treatment with forskolin or dbcAMP could enhance endogenous SNF2L mRNA levels also only in rat primary neurons. CONCLUSION: These results suggest that the CRE consensus sequence in the SNF2L proximal promoter most likely confers constitutive activation and regulation by cAMP in neural cells.


Assuntos
Animais , Humanos , Ratos , Bucladesina/farmacologia , Linhagem Celular , Colforsina/farmacologia , AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/química , Regulação da Expressão Gênica , Luciferases/análise , Neurônios/metabolismo , Células PC12 , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Ratos Wistar , Proteínas Recombinantes de Fusão/análise , Elementos de Resposta , Fatores de Transcrição/química
5.
Indian J Cancer ; 2011 Jul-Sept; 48(3): 351-360
Artigo em Inglês | IMSEAR | ID: sea-144494

RESUMO

One of the major signaling pathways that determine the tumor aggression and patient outcome in pancreatic cancer is the transforming growth factor-beta (TGF-ß) pathway. It is inactivated at various levels in pancreatic cancer and plays a dual role in tumor initiation and progression. The Smad family of proteins transduce signals from the TGF-ß superfamily ligands that regulate cell proliferation, differentiation and death through activation of receptor serine/threonine kinases. This review discusses the structure, function and regulation of various participating Smad family members, and their individual roles in determining the progression and outcome of pancreatic cancer patients, with a special emphasis on Smad4.


Assuntos
Diferenciação Celular , Proliferação de Células , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fosforilação , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais , Proteína Smad4/química , Proteína Smad4/genética , Proteína Smad4/metabolismo , Proteína Smad6/genética , Proteína Smad6/metabolismo , Proteína Smad7/genética , Proteína Smad7/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
6.
Experimental & Molecular Medicine ; : 71-83, 2008.
Artigo em Inglês | WPRIM | ID: wpr-77112

RESUMO

In this study, we investigated the role of Nur77, an orphan nuclear receptor, in HIF-alpha transcriptional activity. We found that Nur77 associates and stabilizes HIF-1alpha via indirect interaction. Nur77 was found to interact with pVHL in vivo via the alpha-domain of pVHL. By binding to pVHL, Nur77 competed with elongin C for pVHL binding. Moreover, Nur77-binding to pVHL inhibited the pVHL-mediated ubiquitination of HIF-1alpha and ultimately increased the stability and transcriptional activity of HIF-1alpha. The ligand-binding domain of Nur77 was found to interact with pVHL and the expression of this ligand-binding domain was sufficient to stabilize and transactivate HIF-1alpha. Under the conditions that cobalt chloride was treated or pVHL was knocked down, Nur77 could not stabilize HIF-alpha. Moreover, Nur77 could not further stabilize HIF-2alpha in A498/VHL stable cells, which is consistent with our finding that Nur77 indirectly stabilizes HIF-alpha by binding to pVHL. Thus, our results suggest that an orphan nuclear receptor Nur77 binds to pVHL, thereby stabilizes and increases HIF-alpha transcriptional activity under the non- hypoxic conditions.


Assuntos
Animais , Humanos , Ratos , Proteínas de Ligação a DNA/química , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Modelos Biológicos , Células PC12 , Ligação Proteica , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína , Receptores Citoplasmáticos e Nucleares/química , Receptores de Esteroides/química , Termodinâmica , Fatores de Transcrição/química , Ativação Transcricional/genética , Ubiquitinação , Regulação para Cima/genética , Proteína Supressora de Tumor Von Hippel-Lindau/antagonistas & inibidores
7.
J Biosci ; 2007 Jan; 32(1): 17-29
Artigo em Inglês | IMSEAR | ID: sea-111328

RESUMO

The sequence motifs present in the replication initiator protein (Rep) of geminiviruses have been compared with those present in all known rolling circle replication initiators. The predicted secondary structures of Rep representing each group of organisms have been compared and found to be conserved. Regions of recombination in the Rep gene and the adjoining 5' intergenic region (IR)of representative species of Geminiviridae have been identified using Recombination Detection Programs. The possible implications of such recombinations on the increasing host range of geminivirus infections are discussed.


Assuntos
Sequência de Aminoácidos , DNA Helicases/química , Proteínas de Ligação a DNA/química , Geminiviridae/química , Dados de Sequência Molecular , Filogenia , Estrutura Secundária de Proteína , Recombinação Genética , Alinhamento de Sequência , Transativadores/química , Proteínas Virais/química , Replicação Viral
8.
Indian J Exp Biol ; 2006 Jan; 44(1): 7-13
Artigo em Inglês | IMSEAR | ID: sea-61164

RESUMO

UV-sensitive mutant strain of Haemophilus influenzae Rd MBH3, is 20 times more sensitive to UV irradiation than the wild type strain. The mutation responsible for increased UV sensitivity of the strain was identified as G --> A transition predicting synthesis of truncated UvrAdeltaC44 protein (Balsara & Joshi). Recombinant UvrAdeltaC44 protein was purified for the first time under denaturing conditions. The molecular weight of the recombinant protein was estimated as approximately100 kDa. Recombinant UvrAdeltaC44 protein was found to be less efficient in its ATPase and DNA binding activity as compared to the wild type protein. Recombinant plasmid carrying uvrAdeltaC44 gene could partially complement the UvrA deficiency in E. coli UvrA mutant.


Assuntos
Adenosina Trifosfatases/química , Proteínas de Bactérias/química , Sequência de Bases , Clonagem Molecular , Reparo do DNA , DNA Bacteriano/genética , Proteínas de Ligação a DNA/química , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Genes Bacterianos , Teste de Complementação Genética , Haemophilus influenzae/genética , Peso Molecular , Tolerância a Radiação , Proteínas Recombinantes/química , Deleção de Sequência , Raios Ultravioleta
9.
J Biosci ; 2005 Dec; 30(5): 657-67
Artigo em Inglês | IMSEAR | ID: sea-110857

RESUMO

In an attempt to determine a cold defense mechanism in plants, we have attempted to characterize changes occurring in the expression of cold-regulated transcript levels in the hot pepper (Capsicum annum), using cDNA microarray analysis, combined with Northern blot analysis. After analysing a 3.1 K hot pepper cDNA microarray, we isolated a total of 317 cold inducible genes. We selected 42 genes which were up-regulated and three genes which were down-regulated due to cold treatment, for further analysis. Among the 45 genes which appeared to be up-regulated by cold, 19 genes appeared to be simultaneously regulated by salt stress. Among the up-regulated cold-stress genes, we identified a variety of transcription factors, including: a family of 4 ethylene-responsive element binding protein (EREBP, designated CaEREBP-C1 to C4) genes, a bZIP protein (CaBZ1), RVA1, Ring domain protein, HSF1, and the WRKY (CaWRKY1) protein. As mentioned earlier, several genes appeared to be induced not only by cold stress, but also simultaneously by salt stress. These genes included: CaEREBP-C3, CaBZ1, putative trans-activator factor, NtPRp27, malate dehydrogenase, putative auxin-repressed protein, protein phosphatase (CaTPP1), SAR8.2 protein precursor, late-embryogenesis abundant protein 5 (LEA5), DNAJ protein homologue, xyloglucanendo-1,4-beta-D-gucanase precursor, PR10, and the putative non-specific lipid transfer protein StnsLTP.


Assuntos
Sequência de Aminoácidos , Northern Blotting/métodos , Capsicum/genética , Temperatura Baixa , Sequência Consenso , Proteínas de Ligação a DNA/química , Desidratação/genética , Regulação para Baixo , Congelamento , Expressão Gênica/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Homeodomínio/química , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Filogenia , Proteínas de Plantas/química , Homologia de Sequência do Ácido Nucleico , Cloreto de Sódio , Fatores de Transcrição/química , Regulação para Cima
10.
Journal of Huazhong University of Science and Technology (Medical Sciences) ; (6): 104-6, 2005.
Artigo em Inglês | WPRIM | ID: wpr-634233

RESUMO

A novel exonuclease protection mediated PCR assay (EPM-PCR) to detect the interaction of protein and DNA at a dioxin-responsive enhancer (DRE) upstream of the CYP1A1 gene in rat hepatic cytosol was established. A double-stranded DNA fragment containing two binding sites was designed and incubated with the aryl hydrocarbon receptor (AhR) transformed by 2,3,7,8-tetrachlorodibenzo-p dioxin (TCDD) to generate TCDD: AhR: DNA complex which could protect receptor-binding DNA against exonuclease II (Exo III) digestion. With Exo III treatment, free DNAs were digested and receptor-bound DNAs remained that could be amplified by PCR. By agarose gel electrophoreses a clear band (285bp) was detected using TCDD-treated sample, while nothing with control samples. To detect transformed AhR-DRE complex, 2 fmol DNAs and 3 ug cytosol proteins were found to be sufficient in the experiment. Compared with gel retardation assay, this new method is more sensitive for monitoring the Ah receptor-enhancer interaction without radioactive pollution.


Assuntos
Sítios de Ligação , Citocromo P-450 CYP1A1/genética , Citosol/metabolismo , Proteínas de Ligação a DNA/química , Exodesoxirribonucleases/química , Fígado/metabolismo , Reação em Cadeia da Polimerase , Ratos Sprague-Dawley , Receptores de Hidrocarboneto Arílico/química , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/química
11.
Experimental & Molecular Medicine ; : 601-607, 2005.
Artigo em Inglês | WPRIM | ID: wpr-24114

RESUMO

Nanog, a homeodomain (HD) transcription factor, plays a critical role in the maintenance of embryonic stem (ES) cell self-renewal. Here, we report the identification of an alternatively-spliced variant of nanog. This variant lacked a stretch of amino acids (residues 168-183) located between the HD and tryptophan-repeat (WR) of the previously-reported full length sequence, suggesting that the deleted sequence functions as a linker and possibly affects the flexibility of the C-terminal transactivation domain relative to the DNA binding domain. Expression of mRNA encoding the splice variant, designated as nanog-delta 48, was much lower than that of the full length version in human ES cells. The ratio of nanog-delta 48 transcript to full length transcript increased, however, in multipotent adult progenitor cells. EMSA analysis revealed that both forms of Nanog were able to bind a nanog binding sequence with roughly the same affinity. A reporter plasmid assay also showed that both variants of nanog modestly repressed transactivation of gata-4, whose expression is proposed to be inhibited by nanog, with comparable potency. We conclude that, despite the difference in primary structure and expression pattern in various stem cells, the alternatively-spliced variant of Nanog has similar activity to that of the full length version.


Assuntos
Humanos , Processamento Alternativo/genética , Sequência de Aminoácidos , Sequência de Bases , Núcleo Celular , Células Cultivadas , Proteínas de Ligação a DNA/química , Éxons/genética , Fator de Transcrição GATA4/metabolismo , Perfilação da Expressão Gênica , Genes Reporter , Proteínas de Homeodomínio/química , Íntrons/genética , Dados de Sequência Molecular , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Ativação Transcricional , Transfecção
13.
J Biosci ; 2003 Jun; 28(4): 443-53
Artigo em Inglês | IMSEAR | ID: sea-111163

RESUMO

Mariner like elements (MLEs) are widely distributed type II transposons with an open reading frame (ORF) for transposase. We studied comparative phylogenetic evolution and inverted terminal repeat (ITR) conservation of MLEs from Indian saturniid silkmoth, Antheraea mylitta with other full length MLEs submitted in the database. Full length elements from A. mylitta were inactive with multiple mutations. Many conserved amino acid blocks were identified after aligning transposase sequences. Mariner signature sequence, DD(34)D was almost inva ri able although a few new class of elements had different signatures. A. mylitta MLEs (Anmmar) get phylogene ti cally classified under cecropia subfamily and cluster closely with the elements from other Bombycoidea superfamily members implying vertical transmission from a common ancestor. ITR analysis showed a conserved sequence of AGGT(2-8N)ATAAGT for forward repeat and AGGT(2-8N)ATGAAAT for reverse repeat. These results and additional work may help us to understand the dynamics of MLE distribution in A. mylitta and construction of appropriate vectors for mariner mediated transgenics.


Assuntos
Sequência de Aminoácidos , Animais , Southern Blotting , Bombyx/genética , Clonagem Molecular , Sequência Conservada , DNA/metabolismo , Proteínas de Ligação a DNA/química , Biblioteca Gênica , Vetores Genéticos , Genoma , Índia , Dados de Sequência Molecular , Família Multigênica , Fases de Leitura Aberta , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Sequências Repetidas Terminais , Transposases
14.
Experimental & Molecular Medicine ; : 122-125, 1999.
Artigo em Inglês | WPRIM | ID: wpr-36360

RESUMO

High selectivity provided by biomolecules such as antibodies and enzymes has been exploited during the last two decades for development of biosensors. Of particular importance are efficient immobilization methods for biomolecules in order to preserve their biological activities. In this study, we have evaluated immobilization strategies for an anti-DNA antibody on a self-assembled monolayer of omega-functionalized thiols. The antibody was immobilized via peptide bond formation between the primary amines in the antibody and the carboxyl groups on the self-assembled monolayer. The peptide bond coupling was achieved by activating COOH groups on the surface through N-Hydroxysuccimide (NHS)-ester formation, followed by acylation of NH2 group in the antibody. DNA binding activity of the immobilized antibody was examined by counting beta emission from 35S-labeled DNA.


Assuntos
Anticorpos Antinucleares , DNA/imunologia , DNA/análise , Proteínas de Ligação a DNA/química , Ouro , Membranas Artificiais , Reação em Cadeia da Polimerase , Polivinil/química , Radioimunoensaio/métodos , Ácido Tióctico/química
15.
Indian J Biochem Biophys ; 1996 Apr; 33(2): 83-7
Artigo em Inglês | IMSEAR | ID: sea-28513

RESUMO

How a short DNA sequence interacts in a sequence specific manner with appropriate protein is understood only in certain systems for which high resolution crystal structures of the protein-DNA complexes are available. The base sequence of DNA is sensed directly (read-out) by the protein through the major or minor groove, while DNA shape also is sensed through multiple interactions with the sugar phosphate backbone. Several repressors, activators and restriction endonucleases complexed with their cognate DNA oligomers are now known and reviewed here. If the binding site on DNA has two fold symmetry, the protein interacts as dimer and uses a variety of structural motifs for specific interaction. The level of specificity of interaction is enhanced by flexibility and/or distortion in either the DNA or protein tertiary structure.


Assuntos
Animais , Sequência de Bases , Proteínas de Ligação a DNA/química , Sequências Hélice-Alça-Hélice , Modelos Moleculares , Estrutura Secundária de Proteína
16.
Indian J Biochem Biophys ; 1995 Dec; 32(6): 447-55
Artigo em Inglês | IMSEAR | ID: sea-27625

RESUMO

Helix stabilising nucleoid protein (HSNP-C') from an acidothermophilic archaeon Sulfolobus acidocaldarius has been characterised with respect to interaction with nucleic acids by gel retardation assay, binding to nucleic acid columns, fluorescence titrations and electron microscopy. The protein exists in solution as very large multimeric aggregates as indicated by cross-linking studies. The protein binds strongly and co-operatively to double stranded DNA. Electron microscopy of the complexes of the protein with DNA shows compact structures suggesting that the protein condenses DNA.


Assuntos
Proteínas de Bactérias/química , DNA Bacteriano/química , Proteínas de Ligação a DNA/química , Conformação de Ácido Nucleico , Sulfolobus acidocaldarius/química
17.
Indian J Biochem Biophys ; 1992 Jun; 29(3): 236-44
Artigo em Inglês | IMSEAR | ID: sea-27587

RESUMO

Structures of (i) 66 amino-acid fragment (residues 567-633) from DNA binding domain of human progesterone receptor (hPR), (ii) a ten base pair DNA sequence d(AGGTCATGCT)2 from hormone responsive element (HRE) and (iii) a complex of these two are optimised by computer modelling and molecular mechanics technique using extensive steric constraints from secondary structure predictions, comparison with the structures of known metalloproteins, geometric constraints imposed by tetrahedral coordination with the zinc ion and comparison with structures of DNA binding domains of human glucocorticoid and estrogen receptors (hGR and hER). Structure of the complex was obtained using genetic modification data on steroid receptors and general consensus about protein-DNA interaction. DNA is in distorted B conformation. Sequence dependent as well as protein-induced conformation changes are noticed. There is change in propeller twist, buckle and angle between glycosyl bonds. However, H-bonding network is preserved. The complex is stabilized with eighteen hydrogen-bonds, mainly between peptide side-chains and backbone phosphate. There are five specific H-bonds between basic amino acid side chains, Lys 22, Lys 26 and Arg 27, and DNA bases, A1, G3, G16 and A17. Gly 19, Ser 20 and Val 23 are in close proximity of DNA.


Assuntos
Sequência de Aminoácidos , Sítios de Ligação , Proteínas de Ligação a DNA/química , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Conformação Proteica , Receptores de Progesterona/química
18.
Indian J Biochem Biophys ; 1992 Feb; 29(1): 13-9
Artigo em Inglês | IMSEAR | ID: sea-28726

RESUMO

To assess the possible functional role of single-strand DNA-binding (SSB) proteins in eucaryotic cell, a comparative study was made of SSB-proteins isolated from chromatin and the nonchromatin fractions of Ehrlich ascites tumour (EAT) cells. No appreciable differences between the two groups could be found either in SDS-gel electrophoretic patterns or in the ssDNA-binding capacity and stimulation of DNA replication in permeable EAT cells. However, the chromatin SSB-proteins incorporated 1.4-times more labelled phosphate in vivo; phosphate assays in the isolated chromatin and nonchromatin SSB-proteins yielded ca. 3 and 2 moles Pi/mole protein, respectively. Both preparations could be further phosphorylated in vitro with Ca-phospholipid-dependent protein kinase and the catalytic subunit of cAMP-dependent protein kinase, but the non-chromatin proteins were phosphorylated to a greater degree. In parallel with phosphorylation, the SSB-proteins displayed stronger binding to ssDNA cellulose. Phosphorylation may thus be a means of regulating the functions of SSB-proteins, in particular their interaction with chromatin.


Assuntos
Animais , Carcinoma de Ehrlich/química , Fracionamento Celular , Cromatina/química , DNA de Cadeia Simples/química , Proteínas de Ligação a DNA/química , Camundongos , Proteínas de Neoplasias/química , Fosforilação , Ligação Proteica
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