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1.
Salud colect ; 11(1): 115-128, ene.-mar. 2015.
Article Dans Espagnol | LILACS | ID: lil-746688

Résumé

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.


Sujets)
Protéines bactériennes/composition chimique , Biophysique/méthodes , Protéines de liaison à l'ADN/composition chimique , Microscopie à force atomique/méthodes , Liaison hydrogène , Cinétique , Modèles moléculaires , Modèles statistiques , Méthode de Monte Carlo , Peptostreptococcus/métabolisme , Conformation des protéines , Dénaturation des protéines , Pliage des protéines , Structure secondaire des protéines , Structure tertiaire des protéines , Protéines/composition chimique , Contrainte mécanique , Température , Facteurs temps , Ubiquitine/composition chimique
3.
Rev. bras. parasitol. vet ; 23(4): 456-462, Oct-Dec/2014. tab, graf
Article Dans Anglais | LILACS, SES-SP | ID: lil-731255

Résumé

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.


Sujets)
Protéines de liaison à l'ADN/physiologie , DNA-directed RNA polymerases/composition chimique , Escherichia coli/enzymologie , Facteur sigma/composition chimique , Facteurs de transcription/physiologie , Protéines virales/physiologie , ADN , Protéines de liaison à l'ADN/composition chimique , DNA-directed RNA polymerases/physiologie , Facteur sigma/physiologie , Facteurs de transcription/composition chimique , Transcription génétique , Techniques de double hybride , Protéines virales/composition chimique
4.
Yonsei Medical Journal ; : 772-777, 2013.
Article Dans Anglais | WPRIM | ID: wpr-211908

Résumé

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.


Sujets)
Animaux , Humains , Rats , Dibutyryl AMP cyclique/pharmacologie , Lignée cellulaire , Colforsine/pharmacologie , AMP cyclique/métabolisme , Protéines de liaison à l'ADN/composition chimique , Régulation de l'expression des gènes , Luciferases/analyse , Neurones/métabolisme , Cellules PC12 , Régions promotrices (génétique) , ARN messager/métabolisme , Rat Wistar , Protéines de fusion recombinantes/analyse , Éléments de réponse , Facteurs de transcription/composition chimique
5.
Indian J Cancer ; 2011 Jul-Sept; 48(3): 351-360
Article Dans Anglais | IMSEAR | ID: sea-144494

Résumé

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.


Sujets)
Différenciation cellulaire , Prolifération cellulaire , Protéines de liaison à l'ADN/composition chimique , Protéines de liaison à l'ADN/génétique , Protéines de liaison à l'ADN/métabolisme , Humains , Tumeurs du pancréas/génétique , Tumeurs du pancréas/métabolisme , Tumeurs du pancréas/anatomopathologie , Phosphorylation , Récepteurs TGF-bêta/génétique , Récepteurs TGF-bêta/métabolisme , Transduction du signal , Protéine Smad-4/composition chimique , Protéine Smad-4/génétique , Protéine Smad-4/métabolisme , Protéine Smad6/génétique , Protéine Smad6/métabolisme , Protéine Smad7/génétique , Protéine Smad7/métabolisme , Facteur de croissance transformant bêta/génétique , Facteur de croissance transformant bêta/métabolisme
6.
Experimental & Molecular Medicine ; : 71-83, 2008.
Article Dans Anglais | WPRIM | ID: wpr-77112

Résumé

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.


Sujets)
Animaux , Humains , Rats , Protéines de liaison à l'ADN/composition chimique , Sous-unité alpha du facteur-1 induit par l'hypoxie/génétique , Modèles biologiques , Cellules PC12 , Liaison aux protéines , Maturation post-traductionnelle des protéines , Structure tertiaire des protéines , Récepteurs cytoplasmiques et nucléaires/composition chimique , Récepteurs aux stéroïdes/composition chimique , Thermodynamique , Facteurs de transcription/composition chimique , Activation de la transcription/génétique , Ubiquitination , Régulation positive/génétique , Protéine Von Hippel-Lindau supresseur de tumeur/antagonistes et inhibiteurs
7.
J Biosci ; 2007 Jan; 32(1): 17-29
Article Dans Anglais | IMSEAR | ID: sea-111328

Résumé

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.


Sujets)
Séquence d'acides aminés , Helicase/composition chimique , Protéines de liaison à l'ADN/composition chimique , Geminiviridae/composition chimique , Données de séquences moléculaires , Phylogenèse , Structure secondaire des protéines , Recombinaison génétique , Alignement de séquences , Transactivateurs/composition chimique , Protéines virales/composition chimique , Réplication virale
8.
Indian J Exp Biol ; 2006 Jan; 44(1): 7-13
Article Dans Anglais | IMSEAR | ID: sea-61164

Résumé

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.


Sujets)
Adenosine triphosphatases/composition chimique , Protéines bactériennes/composition chimique , Séquence nucléotidique , Clonage moléculaire , Réparation de l'ADN , ADN bactérien/génétique , Protéines de liaison à l'ADN/composition chimique , Escherichia coli/génétique , Protéines Escherichia coli/génétique , Gènes bactériens , Test de complémentation , Haemophilus influenzae/génétique , Masse moléculaire , Radiotolérance , Protéines recombinantes/composition chimique , Délétion de séquence , Rayons ultraviolets
9.
J Biosci ; 2005 Dec; 30(5): 657-67
Article Dans Anglais | IMSEAR | ID: sea-110857

Résumé

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.


Sujets)
Séquence d'acides aminés , Technique de Northern/méthodes , Capsicum/génétique , Basse température , Séquence consensus , Protéines de liaison à l'ADN/composition chimique , Déshydratation/génétique , Régulation négative , Congélation , Expression des gènes/génétique , Analyse de profil d'expression de gènes , Régulation de l'expression des gènes végétaux/génétique , Protéines à homéodomaine/composition chimique , Données de séquences moléculaires , Séquençage par oligonucléotides en batterie/méthodes , Phylogenèse , Protéines végétales/composition chimique , Similitude de séquences d'acides nucléiques , Chlorure de sodium , Facteurs de transcription/composition chimique , Régulation positive
10.
Journal of Huazhong University of Science and Technology (Medical Sciences) ; (6): 104-6, 2005.
Article Dans Anglais | WPRIM | ID: wpr-634233

Résumé

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.


Sujets)
Sites de fixation , Cytochrome P-450 CYP1A1/génétique , Cytosol/métabolisme , Protéines de liaison à l'ADN/composition chimique , Exodeoxyribonucleases/composition chimique , Foie/métabolisme , Réaction de polymérisation en chaîne , Rat Sprague-Dawley , Récepteurs à hydrocarbure aromatique/composition chimique , Dibenzodioxines polychlorées/analogues et dérivés , Dibenzodioxines polychlorées/composition chimique
11.
Experimental & Molecular Medicine ; : 601-607, 2005.
Article Dans Anglais | WPRIM | ID: wpr-24114

Résumé

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.


Sujets)
Humains , Épissage alternatif/génétique , Séquence d'acides aminés , Séquence nucléotidique , Noyau de la cellule , Cellules cultivées , Protéines de liaison à l'ADN/composition chimique , Exons/génétique , Facteur de transcription GATA-4/métabolisme , Analyse de profil d'expression de gènes , Gènes rapporteurs , Protéines à homéodomaine/composition chimique , Introns/génétique , Données de séquences moléculaires , Régions promotrices (génétique) , ARN messager/génétique , Activation de la transcription , Transfection
13.
J Biosci ; 2003 Jun; 28(4): 443-53
Article Dans Anglais | IMSEAR | ID: sea-111163

Résumé

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.


Sujets)
Séquence d'acides aminés , Animaux , Technique de Southern , Bombyx/génétique , Clonage moléculaire , Séquence conservée , ADN/métabolisme , Protéines de liaison à l'ADN/composition chimique , Banque de gènes , Vecteurs génétiques , Génome , Inde , Données de séquences moléculaires , Famille multigénique , Cadres ouverts de lecture , Phylogenèse , Réaction de polymérisation en chaîne , Analyse de séquence d'ADN , Similitude de séquences d'acides aminés , Séquences répétées terminales , Transposases
14.
Experimental & Molecular Medicine ; : 122-125, 1999.
Article Dans Anglais | WPRIM | ID: wpr-36360

Résumé

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.


Sujets)
Anticorps antinucléaires , ADN/immunologie , ADN/analyse , Protéines de liaison à l'ADN/composition chimique , Or , Membrane artificielle , Réaction de polymérisation en chaîne , Polyvinyles/composition chimique , Dosage radioimmunologique/méthodes , Acide lipoïque/composition chimique
15.
Indian J Biochem Biophys ; 1996 Apr; 33(2): 83-7
Article Dans Anglais | IMSEAR | ID: sea-28513

Résumé

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.


Sujets)
Animaux , Séquence nucléotidique , Protéines de liaison à l'ADN/composition chimique , Motifs à hélice-boucle-hélice , Modèles moléculaires , Structure secondaire des protéines
16.
Indian J Biochem Biophys ; 1995 Dec; 32(6): 447-55
Article Dans Anglais | IMSEAR | ID: sea-27625

Résumé

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.


Sujets)
Protéines bactériennes/composition chimique , ADN bactérien/composition chimique , Protéines de liaison à l'ADN/composition chimique , Conformation d'acide nucléique , Sulfolobus acidocaldarius/composition chimique
17.
Indian J Biochem Biophys ; 1992 Jun; 29(3): 236-44
Article Dans Anglais | IMSEAR | ID: sea-27587

Résumé

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.


Sujets)
Séquence d'acides aminés , Sites de fixation , Protéines de liaison à l'ADN/composition chimique , Humains , Modèles moléculaires , Données de séquences moléculaires , Conformation d'acide nucléique , Oligodésoxyribonucléotides/composition chimique , Conformation des protéines , Récepteurs à la progestérone/composition chimique
18.
Indian J Biochem Biophys ; 1992 Feb; 29(1): 13-9
Article Dans Anglais | IMSEAR | ID: sea-28726

Résumé

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.


Sujets)
Animaux , Carcinome d'Ehrlich/composition chimique , Fractionnement cellulaire , Chromatine/composition chimique , ADN simple brin/composition chimique , Protéines de liaison à l'ADN/composition chimique , Souris , Protéines tumorales/composition chimique , Phosphorylation , Liaison aux protéines
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