Base de dados : MEDLINE
Pesquisa : D04.345.566.040 [Categoria DeCS]
Referências encontradas : 587 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 59 ir para página                         

  1 / 587 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29340383
[Au] Autor:Syryamina VN; De Zotti M; Toniolo C; Formaggio F; Dzuba SA
[Ad] Endereço:Institute of Chemical Kinetics and Combustion, RAS, Novosibirsk 630090, Russian Federation. dzuba@kinetics.nsc.ru.
[Ti] Título:Alamethicin self-assembling in lipid membranes: concentration dependence from pulsed EPR of spin labels.
[So] Source:Phys Chem Chem Phys;20(5):3592-3601, 2018 Jan 31.
[Is] ISSN:1463-9084
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The antimicrobial action of the peptide antibiotic alamethicin (Alm) is commonly related to peptide self-assembling resulting in the formation of voltage-dependent channels in bacterial membranes, which induces ion permeation. To obtain a deeper insight into the mechanism of channel formation, it is useful to know the dependence of self-assembling on peptide concentration. With this aim, we studied Alm F50/5 spin-labeled analogs in a model 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membrane, for peptide-to-lipid (P/L) ratios varying between 1/1500 and 1/100. Pulsed electron-electron double resonance (PELDOR) spectroscopy reveals that even at the lowest concentration investigated, the Alm molecules assemble into dimers. Moreover, under these conditions, electron spin echo envelope modulation (ESEEM) spectroscopy of D O-hydrated membranes shows an abrupt change from the in-plane to the trans-membrane orientation of the peptide. Therefore, we hypothesize that dimer formation and peptide reorientation are concurrent processes and represent the initial step of peptide self-assembling. By increasing peptide concentration, higher oligomers are formed. A simple kinetic model of equilibrium among monomers, dimers, and pentamers allows for satisfactorily describing the experimental PELDOR data. The inter-label distances in the oligomers obtained from PELDOR experiments become better resolved with increasing P/L ratio, thus suggesting that the supramolecular organization of the higher-order oligomers becomes more defined.
[Mh] Termos MeSH primário: Alameticina/química
Bicamadas Lipídicas/química
[Mh] Termos MeSH secundário: Alameticina/metabolismo
Sequência de Aminoácidos
Dimerização
Espectroscopia de Ressonância de Spin Eletrônica
Cinética
Bicamadas Lipídicas/metabolismo
Fosfatidilcolinas/química
Marcadores de Spin
Água/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Lipid Bilayers); 0 (Phosphatidylcholines); 0 (Spin Labels); 059QF0KO0R (Water); 27061-78-5 (Alamethicin); TE895536Y5 (1-palmitoyl-2-oleoylphosphatidylcholine)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180226
[Lr] Data última revisão:
180226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180118
[St] Status:MEDLINE
[do] DOI:10.1039/c7cp07298h


  2 / 587 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28450394
[Au] Autor:Korge P; John SA; Calmettes G; Weiss JN
[Ad] Endereço:From the UCLA Cardiovascular Research Laboratory and the Departments of Medicine (Cardiology) and Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095.
[Ti] Título:Reactive oxygen species production induced by pore opening in cardiac mitochondria: The role of complex II.
[So] Source:J Biol Chem;292(24):9896-9905, 2017 06 16.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Succinate-driven reverse electron transport (RET) through complex I is hypothesized to be a major source of reactive oxygen species (ROS) that induces permeability transition pore (PTP) opening and damages the heart during ischemia/reperfusion. Because RET can only generate ROS when mitochondria are fully polarized, this mechanism is self-limiting once PTP opens during reperfusion. In the accompanying article (Korge, P., Calmettes, G., John, S. A., and Weiss, J. N. (2017) 292, 9882-9895), we showed that ROS production after PTP opening can be sustained when complex III is damaged (simulated by antimycin). Here we show that complex II can also contribute to sustained ROS production in isolated rabbit cardiac mitochondria following inner membrane pore formation induced by either alamethicin or calcium-induced PTP opening. Two conditions are required to maximize malonate-sensitive ROS production by complex II in isolated mitochondria: ( ) complex II inhibition by atpenin A5 or complex III inhibition by stigmatellin that results in succinate-dependent reduction of the dicarboxylate-binding site of complex II (site II ); ( ) pore opening in the inner membrane resulting in rapid efflux of succinate/fumarate and other dicarboxylates capable of competitively binding to site II The decrease in matrix [dicarboxylate] allows O access to reduced site II , thereby making electron donation to O possible, explaining the rapid increase in ROS production provided that site II is reduced. Because ischemia is known to inhibit complexes II and III and increase matrix succinate/fumarate levels, we hypothesize that by allowing dicarboxylate efflux from the matrix, PTP opening during reperfusion may activate sustained ROS production by this mechanism after RET-driven ROS production has ceased.
[Mh] Termos MeSH primário: Complexo II de Transporte de Elétrons/metabolismo
Mitocôndrias Cardíacas/metabolismo
Modelos Moleculares
Espécies Reativas de Oxigênio/agonistas
[Mh] Termos MeSH secundário: Alameticina/farmacologia
Animais
Sítios de Ligação
Ligação Competitiva
Biocatálise/efeitos dos fármacos
Sinalização do Cálcio/efeitos dos fármacos
Transporte de Elétrons/efeitos dos fármacos
Complexo II de Transporte de Elétrons/antagonistas & inibidores
Complexo II de Transporte de Elétrons/química
Inibidores Enzimáticos/farmacologia
Fumaratos/metabolismo
Ionóforos/farmacologia
Potencial da Membrana Mitocondrial/efeitos dos fármacos
Mitocôndrias Cardíacas/química
Mitocôndrias Cardíacas/efeitos dos fármacos
Oxirredução
Permeabilidade/efeitos dos fármacos
Polienos/farmacologia
Porosidade
Piridonas/farmacologia
Coelhos
Espécies Reativas de Oxigênio/metabolismo
Ácido Succínico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Fumarates); 0 (Ionophores); 0 (Polyenes); 0 (Pyridones); 0 (Reactive Oxygen Species); 119509-24-9 (atpenin A5); 27061-78-5 (Alamethicin); 91682-96-1 (stigmatellin); AB6MNQ6J6L (Succinic Acid); EC 1.3.5.1 (Electron Transport Complex II)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:180205
[Lr] Data última revisão:
180205
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M116.768325


  3 / 587 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28450391
[Au] Autor:Korge P; Calmettes G; John SA; Weiss JN
[Ad] Endereço:From the UCLA Cardiovascular Research Laboratory and the Departments of Medicine (Cardiology) and Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095.
[Ti] Título:Reactive oxygen species production induced by pore opening in cardiac mitochondria: The role of complex III.
[So] Source:J Biol Chem;292(24):9882-9895, 2017 06 16.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Recent evidence has implicated succinate-driven reverse electron transport (RET) through complex I as a major source of damaging reactive oxygen species (ROS) underlying reperfusion injury after prolonged cardiac ischemia. However, this explanation may be incomplete, because RET on reperfusion is self-limiting and therefore transient. RET can only generate ROS when mitochondria are well polarized, and it ceases when permeability transition pores (PTP) open during reperfusion. Because prolonged ischemia/reperfusion also damages electron transport complexes, we investigated whether such damage could lead to ROS production after PTP opening has occurred. Using isolated cardiac mitochondria, we demonstrate a novel mechanism by which antimycin-inhibited complex III generates significant amounts of ROS in the presence of Mg and NAD and the absence of exogenous substrates upon inner membrane pore formation by alamethicin or Ca -induced PTP opening. We show that H O production under these conditions is related to Mg -dependent NADH generation by malic enzyme. H O production is blocked by stigmatellin, indicating its origin from complex III, and by piericidin, demonstrating the importance of NADH-related ubiquinone reduction for ROS production under these conditions. For maximal ROS production, the rate of NADH generation has to be equal or below that of NADH oxidation, as further increases in [NADH] elevate ubiquinol-related complex III reduction beyond the optimal range for ROS generation. These results suggest that if complex III is damaged during ischemia, PTP opening may result in succinate/malate-fueled ROS production from complex III due to activation of malic enzyme by increases in matrix [Mg ], [NAD ], and [ADP].
[Mh] Termos MeSH primário: Complexo III da Cadeia de Transporte de Elétrons/metabolismo
Malato Desidrogenase/metabolismo
Mitocôndrias Cardíacas/metabolismo
Espécies Reativas de Oxigênio/agonistas
[Mh] Termos MeSH secundário: Difosfato de Adenosina/metabolismo
Alameticina/farmacologia
Animais
Antimicina A/análogos & derivados
Antimicina A/farmacologia
Biocatálise/efeitos dos fármacos
Sinalização do Cálcio/efeitos dos fármacos
Complexo III da Cadeia de Transporte de Elétrons/antagonistas & inibidores
Ativação Enzimática/efeitos dos fármacos
Inibidores Enzimáticos/farmacologia
Peróxido de Hidrogênio/metabolismo
Ionóforos/farmacologia
Magnésio/metabolismo
Malato Desidrogenase/química
Mitocôndrias Cardíacas/química
Mitocôndrias Cardíacas/efeitos dos fármacos
NAD/metabolismo
Oxirredução
Polienos/farmacologia
Porosidade/efeitos dos fármacos
Piridinas/farmacologia
Coelhos
Espécies Reativas de Oxigênio/metabolismo
Ubiquinona/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Ionophores); 0 (Polyenes); 0 (Pyridines); 0 (Reactive Oxygen Species); 0U46U6E8UK (NAD); 11118-72-2 (antimycin); 1339-63-5 (Ubiquinone); 27061-78-5 (Alamethicin); 61D2G4IYVH (Adenosine Diphosphate); 642-15-9 (Antimycin A); 8VT513UJ9R (piericidin A); 91682-96-1 (stigmatellin); BBX060AN9V (Hydrogen Peroxide); EC 1.1.1.37 (Malate Dehydrogenase); EC 1.10.2.2 (Electron Transport Complex III); I38ZP9992A (Magnesium)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171228
[Lr] Data última revisão:
171228
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M116.768317


  4 / 587 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28445757
[Au] Autor:Faust JE; Yang PY; Huang HW
[Ad] Endereço:Department of Physics and Astronomy, Rice University, Houston, Texas.
[Ti] Título:Action of Antimicrobial Peptides on Bacterial and Lipid Membranes: A Direct Comparison.
[So] Source:Biophys J;112(8):1663-1672, 2017 Apr 25.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The bacterial membrane represents an attractive target for the design of new antibiotics to combat widespread bacterial resistance. Understanding how antimicrobial peptides (AMPs) and other membrane-active agents attack membranes could facilitate the design of new, effective antimicrobials. Despite intense study of AMPs on model membranes, we do not know how well the mechanism of attack translates to real biological membranes. To that end, we have characterized the attack of AMPs on Escherichia coli cytoplasmic membranes and directly compared this action to model membranes. AMPs induce membrane permeability in E. coli spheroplasts or giant unilamellar vesicles (GUVs) under well-defined concentrations of AMPs and fluorescent molecules. The action of AMPs on spheroplasts is unique in producing an intracellular fluorescence intensity time curve that increases in a sigmoidal fashion to a steady state. This regular pattern is reproducible by melittin, LL37, and alamethicin but not by CCCP or daptomycin, agents known to cause ion leakage. Remarkably, a similar pattern was also reproduced in GUVs. Indeed the steady-state membrane permeability induced by AMPs is quantitatively the same in spheroplasts and GUVs. There are, however, interesting dissimilarities in details that reveal differences between bacterial and lipid membranes. Spheroplast membranes are permeabilized by a wide range of AMP concentrations to the same steady-state membrane permeability. In contrast, only a narrow range of AMP concentrations permeabilized GUVs to a steady state. Tension in GUVs also influences the action of AMPs, whereas the spheroplast membranes are tensionless. Despite these differences, our results provide a strong support for using model membranes to study the molecular interactions of AMPs with bacterial membranes. As far as we know, this is the first time the actions of AMPs, on bacterial membranes and on model membranes, have been directly and quantitatively compared.
[Mh] Termos MeSH primário: Alameticina/metabolismo
Peptídeos Catiônicos Antimicrobianos/metabolismo
Membrana Celular/metabolismo
Escherichia coli/metabolismo
Meliteno/metabolismo
[Mh] Termos MeSH secundário: Anti-Infecciosos/farmacologia
Membrana Celular/efeitos dos fármacos
Permeabilidade da Membrana Celular
Escherichia coli/efeitos dos fármacos
Corantes Fluorescentes
Bicamadas Lipídicas/química
Microscopia Confocal
Esferoplastos/metabolismo
Lipossomas Unilamelares/metabolismo
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Infective Agents); 0 (Antimicrobial Cationic Peptides); 0 (Fluorescent Dyes); 0 (Lipid Bilayers); 0 (Unilamellar Liposomes); 143108-26-3 (CAP18 lipopolysaccharide-binding protein); 20449-79-0 (Melitten); 27061-78-5 (Alamethicin)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170807
[Lr] Data última revisão:
170807
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170427
[St] Status:MEDLINE


  5 / 587 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28063425
[Au] Autor:Afanasyeva EF; Syryamina VN; Dzuba SA
[Ad] Endereço:Voevodsky Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, 630090 Novosibirsk, Russia and Department of Physics, Novosibirsk State University, 630090 Novosibirsk, Russia.
[Ti] Título:Communication: Alamethicin can capture lipid-like molecules in the membrane.
[So] Source:J Chem Phys;146(1):011103, 2017 Jan 07.
[Is] ISSN:1089-7690
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Alamethicin (Alm) is a 19-mer antimicrobial peptide produced by fungus Trichoderma viride. Above a threshold concentration, Alm forms pores across the membrane, providing a mechanism of its antimicrobial action. Here we show that at a small concentration which is below the threshold value, Alm participates in formation of nanoscale lipid-mediated clusters of guest lipid-like molecules in the membrane. These results are obtained by electron spin echo (ESE) technique-a pulsed version of electron paramagnetic resonance-on spin-labeled stearic acid in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer with Alm added at 1/200 peptide-to-lipid ratio. ESE decay measurements are interpreted assuming that stearic acid molecules in the membrane are assembling around the Alm molecule. One may suggest that this Alm capturing effect on the guest lipid-like molecules could be important for the peptide antimicrobial action.
[Mh] Termos MeSH primário: Alameticina/farmacologia
Membrana Celular/efeitos dos fármacos
Membrana Celular/metabolismo
Fosfatidilcolinas/metabolismo
[Mh] Termos MeSH secundário: Alameticina/química
Sequência de Aminoácidos
Espectroscopia de Ressonância de Spin Eletrônica
Fosfatidilcolinas/química
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Phosphatidylcholines); 27061-78-5 (Alamethicin); TE895536Y5 (1-palmitoyl-2-oleoylphosphatidylcholine)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170731
[Lr] Data última revisão:
170731
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170109
[St] Status:MEDLINE
[do] DOI:10.1063/1.4973703


  6 / 587 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27940284
[Au] Autor:Vollmer M; Klingebiel M; Rohn S; Maul R
[Ad] Endereço:Institute of Food Chemistry, Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany. Electronic address: Maren.Vollmer@chemie.uni-hamburg.de.
[Ti] Título:Alamethicin for using in bioavailability studies? - Re-evaluation of its effect.
[So] Source:Toxicol In Vitro;39:111-118, 2017 Mar.
[Is] ISSN:1879-3177
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A major pathway for the elimination of drugs is the biliary and renal excretion following the formation of more hydrophilic secondary metabolites such as glucuronides. For in vitro investigations of the phase II metabolism, hepatic microsomes are commonly used in the combination with the pore-forming peptide alamethicin, also to give estimates for the in vivo situation. Thus, alamethicin may represent a neglected parameter in the characterization of microsomal in vitro assays. In the present study, the influence of varying alamethicin concentrations on glucuronide formation of selected phenolic compounds was investigated systematically. A correlation between the alamethicin impact and the lipophilicity of the investigated substrates was analyzed as well. Lipophilicity was determined by the logarithm of the octanol-water partition coefficient. For every substrate, a distinct alamethicin concentration could be detected leading to a maximal glucuronidation activity. Further increase of the alamethicin application led to negative effects. The differences between the maximum depletion rates with and without alamethicin addition varied between 2.7% and 18.2% depending on the substrate. A dependence on the lipophilicity could not be confirmed. Calculation of the apparent intrinsic clearance led to a more than 2-fold increase using the most effective alamethicin concentration compared to the alamethicin free control.
[Mh] Termos MeSH primário: Alameticina/farmacologia
Glucuronídeos/metabolismo
Fenóis/farmacologia
[Mh] Termos MeSH secundário: 1-Octanol/química
Animais
Antibacterianos/farmacologia
Disponibilidade Biológica
Interações Medicamentosas
Masculino
Microssomos Hepáticos/metabolismo
Fenóis/química
Ratos Sprague-Dawley
Água/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Glucuronides); 0 (Phenols); 059QF0KO0R (Water); 27061-78-5 (Alamethicin); NV1779205D (1-Octanol)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170327
[Lr] Data última revisão:
170327
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161213
[St] Status:MEDLINE


  7 / 587 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27926846
[Au] Autor:Salnikov ES; Raya J; De Zotti M; Zaitseva E; Peggion C; Ballano G; Toniolo C; Raap J; Bechinger B
[Ad] Endereço:Institute of Chemistry, University of Strasbourg/CNRS, UMR7177, Strasbourg, France.
[Ti] Título:Alamethicin Supramolecular Organization in Lipid Membranes from F Solid-State NMR.
[So] Source:Biophys J;111(11):2450-2459, 2016 Dec 06.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Alamethicins (ALMs) are antimicrobial peptides of fungal origin. Their sequences are rich in hydrophobic amino acids and strongly interact with lipid membranes, where they cause a well-defined increase in conductivity. Therefore, the peptides are thought to form transmembrane helical bundles in which the more hydrophilic residues line a water-filled pore. Whereas the peptide has been well characterized in terms of secondary structure, membrane topology, and interactions, much fewer data are available regarding the quaternary arrangement of the helices within lipid bilayers. A new, to our knowledge, fluorine-labeled ALM derivative was prepared and characterized when reconstituted into phospholipid bilayers. As a part of these studies, C F -labeled compounds were characterized and calibrated for the first time, to our knowledge, for F solid-state NMR distance and oligomerization measurements by centerband-only detection of exchange (CODEX) experiments, which opens up a large range of potential labeling schemes. The F- F CODEX solid-state NMR experiments performed with ALM in POPC lipid bilayers and at peptide/lipid ratios of 1:13 are in excellent agreement with molecular-dynamics calculations of dynamic pentameric assemblies. When the peptide/lipid ratio was lowered to 1:30, ALM was found in the dimeric form, indicating that the supramolecular organization is tuned by equilibria that can be shifted by changes in environmental conditions.
[Mh] Termos MeSH primário: Alameticina/química
Antibacterianos/química
Membrana Celular/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Membrana Celular/metabolismo
Fenômenos Eletrofisiológicos
Espectroscopia de Ressonância Magnética
Fosfatidilcolinas/metabolismo
Multimerização Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Phosphatidylcholines); 27061-78-5 (Alamethicin); TE895536Y5 (1-palmitoyl-2-oleoylphosphatidylcholine)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170704
[Lr] Data última revisão:
170704
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161208
[St] Status:MEDLINE


  8 / 587 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27653483
[Au] Autor:Perrin BS; Pastor RW
[Ad] Endereço:Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.
[Ti] Título:Simulations of Membrane-Disrupting Peptides I: Alamethicin Pore Stability and Spontaneous Insertion.
[So] Source:Biophys J;111(6):1248-1257, 2016 Sep 20.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:An all-atom molecular dynamics simulation of the archetype barrel-stave alamethicin (alm) pore in a 1,2-dioleoyl-sn-glycero-3-phosphocholine bilayer at 313 K indicates that ∼7 µs is required for equilibration of a preformed 6-peptide pore; the pore remains stable for the duration of the remaining 7 µs of the trajectory, and the structure factors agree well with experiment. A 5 µs simulation of 10 surface-bound alm peptides shows significant peptide unfolding and some unbinding, but no insertion. Simulations at 363 and 413 K with a -0.2 V electric field yield peptide insertion in 1 µs. Insertion is initiated by the folding of residues 3-11 into an α-helix, and mediated by membrane water or by previously inserted peptides. The stability of five alm pore peptides at 413 K with a -0.2 V electric field demonstrates a significant preference for a transmembrane orientation. Hence, and in contrast to the cationic antimicrobial peptide described in the following article, alm shows a strong preference for the inserted over the surface-bound state.
[Mh] Termos MeSH primário: Alameticina/química
Antibacterianos/química
Bicamadas Lipídicas/química
[Mh] Termos MeSH secundário: Alameticina/metabolismo
Animais
Antibacterianos/metabolismo
Peptídeos Catiônicos Antimicrobianos/química
Campos Eletromagnéticos
Proteínas de Peixes/química
Peixes
Proteínas Fúngicas/química
Proteínas Fúngicas/metabolismo
Glicerilfosforilcolina/análogos & derivados
Glicerilfosforilcolina/química
Interações Hidrofóbicas e Hidrofílicas
Simulação de Dinâmica Molecular
Fosfatidilcolinas
Ligação Proteica
Conformação Proteica em alfa-Hélice
Dobramento de Proteína
Trichoderma
Viscosidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Antimicrobial Cationic Peptides); 0 (Fish Proteins); 0 (Fungal Proteins); 0 (Lipid Bilayers); 0 (Phosphatidylcholines); 0 (moronecidin protein, Morone saxatilis); 27061-78-5 (Alamethicin); 60M22SGW66 (Glycerylphosphorylcholine); EDS2L3ODLV (1,2-oleoylphosphatidylcholine)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160923
[St] Status:MEDLINE


  9 / 587 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27378130
[Au] Autor:Meena S; Mehla J; Kumar R; Sood SK
[Ad] Endereço:Division of Animal Biochemistry, National Dairy Research Institute, Karnal, Haryana, 132001, India. sunitameena1188@gmail.com.
[Ti] Título:Common Mechanism of Cross-Resistance Development in Pathogenic Bacteria Bacillus cereus Against Alamethicin and Pediocin Involves Alteration in Lipid Composition.
[So] Source:Curr Microbiol;73(4):534-41, 2016 Oct.
[Is] ISSN:1432-0991
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:To understand the mechanism of development of cross-resistance in food pathogen Bacillus cereus against an antimicrobial peptide pediocin and antibiotic alamethicin, the present study was designed. Pediococcus pentosaceus was taken as a source of pediocin, and it was purified by ammonium sulphate precipitation followed by cation exchange chromatography with 14.01-fold purity and 14.4 % recovery. B. cereus strains alamethicin-resistant strains (IC50 3.23 µg/ml) were selected from sensitive population with IC50 2.37 µg/ml. The development of resistance in B. cereus against alamethicin was associated with decrease in alamethicin-membrane interaction observed by in vitro assay. Resistant strain of B. cereus was found to harbour one additional general lipid as compared to sensitive strain, one amino group lacking phospholipid and one amino group containing phospholipid (ACP). In addition, ACP content was increased in resistant mutant (29.7 %) as compared to sensitive strain (14.56 %). The alamethicin-resistant mutant B. cereus also showed increased IC50 (58.8 AU/ml) for pediocin as compared to sensitive strain (IC50 47.8 AU/ml). Cross-resistance to pediocin and alamethicin in resistant mutant of B. cereus suggested a common mechanism of resistance. Therefore, this understanding could result in the development of peptide which will be effective against the resistant strains that share same mechanism of resistance.
[Mh] Termos MeSH primário: Alameticina/farmacologia
Antibacterianos/farmacologia
Bacillus cereus/efeitos dos fármacos
Bacillus cereus/metabolismo
Farmacorresistência Bacteriana
Pediocinas/farmacologia
Fosfolipídeos/metabolismo
[Mh] Termos MeSH secundário: Alameticina/isolamento & purificação
Alameticina/metabolismo
Antibacterianos/isolamento & purificação
Antibacterianos/metabolismo
Bacillus cereus/química
Bacillus cereus/genética
Pediocinas/isolamento & purificação
Pediocinas/metabolismo
Pediococcus/química
Pediococcus/metabolismo
Fosfolipídeos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Pediocins); 0 (Phospholipids); 27061-78-5 (Alamethicin)
[Em] Mês de entrada:1701
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160706
[St] Status:MEDLINE
[do] DOI:10.1007/s00284-016-1090-0


  10 / 587 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
[PMID]:26947351
[Au] Autor:Ladd MA; Fitzsimmons PN; Nichols JW
[Ad] Endereço:a United States Environmental Protection Agency (US EPA), ORD, NHEERL, Mid-Continent Ecology Division , Duluth , MN , USA.
[Ti] Título:Optimization of a UDP-glucuronosyltransferase assay for trout liver S9 fractions: activity enhancement by alamethicin, a pore-forming peptide.
[So] Source:Xenobiotica;46(12):1066-1075, 2016 Dec.
[Is] ISSN:1366-5928
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:1. An existing assay for UDP-glucuronosyltransferase (UGT) activity in trout liver microsomes was optimized using trout liver S9 fractions. Individual experiments were conducted to determine the time dependence of UGT activity as well as optimal levels of S9 protein, uridine 5'-diphosphoglucuronic acid (UDPGA), substrate (p-nitrophenol) and alamethicin, a pore-forming agent added to eliminate latency. 2. Addition of Mg (to 1 mM) or bovine serum albumin (BSA; to 2% w/v) had variable effects on activity, but these effects were minor. Eliminating alamethicin from the system resulted in very low levels of activity. A portion of this activity could be recovered by adding Triton X-100 or Brij 58; however, the optimal concentration range for either detergent was very narrow. 3. When expressed on a pmol/min/g liver basis, UGT activities determined using this updated assay were substantially higher than those reported previously for uninduced trout. 4. These results clearly demonstrate the advantages of using alamethicin for the removal of latency in UGT activity studies with trout and may have broad implications for the study of UGTs in other fish species.
[Mh] Termos MeSH primário: Alameticina/farmacologia
Bioensaio/métodos
Glucuronosiltransferase/metabolismo
Ionóforos/farmacologia
Extratos Hepáticos/metabolismo
[Mh] Termos MeSH secundário: Animais
Fígado
Truta
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Ionophores); 0 (Liver Extracts); 27061-78-5 (Alamethicin); EC 2.4.1.17 (Glucuronosyltransferase)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170214
[Lr] Data última revisão:
170214
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160308
[St] Status:MEDLINE



página 1 de 59 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde