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[PMID]: 28684313 [Au] Autor: Potvin-Fournier K; Valois-Paillard G; Lefèvre T; Cantin L; Salesse C; Auger M [Ad] Endereço: Département de Chimie, Regroupement Québécois de Recherche sur la Fonction, L'ingénierie et L'application des Protéines (PROTEO), Centre de Recherche sur les Matériaux Avancés (CERMA), Centre Québécois sur les Matériaux Fonctionnels (CQMF), Université Laval, Pavillon Alexandre-Vachon, 1045 Avenue de [Ti] Título: Membrane fluidity is a driving force for recoverin myristoyl immobilization in zwitterionic lipids. [So] Source: Biochem Biophys Res Commun;490(4):1268-1273, 2017 Sep 02. [Is] ISSN: 1090-2104 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Recoverin is the only protein for which the phenomenon of calcium-myristoyl switch has been demonstrated without ambiguity. It is located in rod disk membranes where the highest content in polyunsaturated lipid acyl chains can be found. However, although essential to better understand the inactivation of the phototransduction process, the role of membrane fluidity on recoverin recruitment is unclear. We have therefore investigated the immobilization of the recoverin myristoyl moiety in the presence of phosphocholine bilayers using H solid-state NMR spectroscopy. Several lipids with different acyl chains were selected to investigate model membranes characterized by different fluidity. Immobilization of the recoverin myristoyl moiety was successfully observed but only in the presence of calcium and in specific lipid disordered states, showing that an optimal fluidity is required for recoverin immobilization. [Mh] Termos MeSH primário: Cálcio/química Bicamadas Lipídicas/química Ácido Mirístico/química Recoverina/química Tensoativos/química [Mh] Termos MeSH secundário: Dimiristoilfosfatidilcolina/química Difenilexatrieno/química Espectroscopia de Ressonância Magnética Fluidez de Membrana Fosfatidilcolinas/química Fosfatidilgliceróis/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Lipid Bilayers); 0 (Phosphatidylcholines); 0 (Phosphatidylglycerols); 0 (RCVRN protein, human); 0 (Surface-Active Agents); 0 (didocosahexaenoylphosphatidylcholine); 0I3V7S25AW (Myristic Acid); 135844-11-0 (Recoverin); 1720-32-7 (Diphenylhexatriene); 66322-31-4 (1,2-dioleoyl-sn-glycero-3-phosphoglycerol); EDS2L3ODLV (1,2-oleoylphosphatidylcholine); SY7Q814VUP (Calcium); U86ZGC74V5 (Dimyristoylphosphatidylcholine) [Em] Mês de entrada: 1708 [Cu] Atualização por classe: 171116 [Lr] Data última revisão: 171116 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170708 [St] Status: MEDLINE

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[PMID]: 27987460 [Au] Autor: Tanaka H; Oasa S; Kinjo M; Tange K; Nakai Y; Harashima H; Akita H [Ad] Endereço: Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Sapporo City, Hokkaido 060-0812, Japan. [Ti] Título: Temperature and pH sensitivity of a stabilized self-nanoemulsion formed using an ionizable lipid-like material via an oil-to-surfactant transition. [So] Source: Colloids Surf B Biointerfaces;151:95-101, 2017 Mar 01. [Is] ISSN: 1873-4367 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: Lipids functionalized with tertiary amines (ionizable lipids) for a pH-dependent positive charge have been developed extensively as a carrier material for delivering nucleic acids. We previously developed an SS-cleavable proton-activated lipid-like material (ssPalm) as a component of a functionalized lipid envelope structure of a nanoparticle that encapsulated plasmid DNA and short interfering RNA. In this study, we report on the unique characteristics of such an ionizable lipid: the formation of a nano-sized emulsion (ave. 40nm) via pH-triggered self-emulsification in the absence of a cargo (nucleic acids). The particle has a neutral charge at physiological pH and is stabilized by helper lipids and polyethyleneglycol (PEG)-conjugated lipids. The generalized polarization of 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan), which indicates the surface polarity caused by the invasion of water onto the surface, changes dynamically in response to pH and temperature, while the fluidity of the intra-particle compartment, as measured by the fluorescence anisotropy of 1,6-Diphenyl-1,3,5-hexatriene (DPH), is not affected. Even when the particle contains a high density of PEG on the surface, it shows a high fusogenecity to negatively charged liposomes in response to an acidic pH to a higher degree than a conventional cationic lipid. These characteristics suggest that the ssPalm particle possesses unique properties for delivering lipophilic drugs across the biomembrane. [Mh] Termos MeSH primário: 2-Naftilamina/análogos & derivados Lauratos/química Lipídeos/química Lipossomos/química Tensoativos/química [Mh] Termos MeSH secundário: 2-Naftilamina/química Anisotropia Difenilexatrieno/química Emulsões Etanol/química Concentração de Íons de Hidrogênio Nanopartículas/química Ácidos Nucleicos/química Óleos Tamanho da Partícula Plasmídeos/metabolismo Polietilenoglicóis/química RNA Interferente Pequeno/metabolismo Solubilidade Propriedades de Superfície Temperatura Ambiente Água/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Emulsions); 0 (Laurates); 0 (Lipids); 0 (Liposomes); 0 (Nucleic Acids); 0 (Oils); 0 (RNA, Small Interfering); 0 (Surface-Active Agents); 059QF0KO0R (Water); 1720-32-7 (Diphenylhexatriene); 30IQX730WE (Polyethylene Glycols); 3K9958V90M (Ethanol); CKR7XL41N4 (2-Naphthylamine); Y97FBL93VW (laurdan) [Em] Mês de entrada: 1703 [Cu] Atualização por classe: 170328 [Lr] Data última revisão: 170328 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161218 [St] Status: MEDLINE

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[PMID]: 27745558 [Au] Autor: Lopes PA; Martins AP; Martins SV; Madeira MS; Santos NC; Moura TF; Prates JA; Soveral G [Ad] Endereço: 1CIISA, Faculdade de Medicina Veterinária,Universidade de Lisboa,1300-477 Lisboa,Portugal. [Ti] Título: Higher membrane fluidity mediates the increased subcutaneous fatty acid content in pigs fed reduced protein diets. [So] Source: Animal;11(4):713-719, 2017 Apr. [Is] ISSN: 1751-732X [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: The production of pork with moderate amounts of intramuscular fat (IMF) without an increase in subcutaneous fat is highly desirable for the meat industry. Several studies indicate that dietary protein reduction during the growing-finishing period of pigs enhances IMF content, but its consequence on carcass fat deposition is still contradictory. In this study, we hypothesized that the effects of reduced protein diets (RPD), corrected or not with the limiting amino acid lysine, on subcutaneous fat deposition from pigs with distinct genotypes are mediated by adipose membranes biophysical properties. In total, 36 crossbred (Large White×Landrace×Pietrain - a lean genotype) and purebred (Alentejana breed - a fatty genotype) male pigs were randomly assigned to the control group, the RPD group or the reduced protein diet equilibrated for lysine (RPDL) group, allowing a 2×3 factorial arrangement (n=6). Backfat thickness and total fatty acid content were higher in Alentejana relative to crossbred pigs. Although dietary treatments did not change backfat thickness, RPD and RPDL increased total fatty acids content of subcutaneous fat. In order to understand this effect, adipose tissue membranes isolated from pig's subcutaneous fat were assayed for glycerol permeability and fluidity, using 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-(4-(trimethylamino)-phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) probes. The glycerol transport across adipose membranes was not mediated by aquaglyceroporins and remained unchanged across dietary groups. Regardless of lysine correction, RPD increased membrane fluidity at the hydrocarbon region (lower DPH fluorescence anisotropy) in both genotypes of pigs. This result was associated with a lower ratio between oleic acid and linoleic acid on membrane's fatty acid composition. Adipose membrane's cholesterol content was independent from genotype and diet. Taken together, the present study shows that dietary protein reduction is successful in maintaining backfat thickness, although a negative side effect was observed on total fatty acids in subcutaneous fat, which may be due to changes in the fluidity of adipose membranes. [Mh] Termos MeSH primário: Dieta com Restrição de Proteínas/veterinária Ácidos Graxos/análise Fluidez de Membrana Carne Vermelha/normas Gordura Subcutânea/química Suínos/fisiologia [Mh] Termos MeSH secundário: Tecido Adiposo/metabolismo Animais Composição Corporal Cruzamento Proteínas na Dieta/administração & dosagem Proteínas na Dieta/metabolismo Difenilexatrieno/análogos & derivados Lisina/metabolismo Masculino Obesidade/metabolismo Gordura Subcutânea/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Dietary Proteins); 0 (Fatty Acids); 1720-32-7 (Diphenylhexatriene); 71316-28-4 (1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene); K3Z4F929H6 (Lysine) [Em] Mês de entrada: 1706 [Cu] Atualização por classe: 170629 [Lr] Data última revisão: 170629 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161018 [St] Status: MEDLINE [do] DOI: 10.1017/S1751731116001968

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[PMID]: 27886150 [Au] Autor: Liao ZG; Tang T; Guan XJ; Dong W; Zhang J; Zhao GW; Yang M; Liang XL [Ad] Endereço: Key Laboratory of Modern Preparation of TCM, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, China. lyzlyg@163.com. [Ti] Título: Improvement of Transmembrane Transport Mechanism Study of Imperatorin on P-Glycoprotein-Mediated Drug Transport. [So] Source: Molecules;21(12), 2016 Nov 24. [Is] ISSN: 1420-3049 [Cp] País de publicação: Switzerland [La] Idioma: eng [Ab] Resumo: P-glycoprotein (P-gp) affects the transport of many drugs; including puerarin and vincristine. Our previous study demonstrated that imperatorin increased the intestinal absorption of puerarin and vincristine by inhibiting P-gp-mediated drug efflux. However; the underlying mechanism was not known. The present study investigated the mechanism by which imperatorin promotes P-gp-mediated drug transport. We used molecular docking to predict the binding force between imperatorin and P-gp and the effect of imperatorin on P-gp activity. P-gp efflux activity and P-gp ATPase activity were measured using a rhodamine 123 (Rh-123) accumulation assay and a Pgp-Glo™ assay; respectively. The fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH) was used to assess cellular membrane fluidity in MDCK-MDR1 cells. Western blotting was used to analyze the effect of imperatorin on P-gp expression; and P-gp mRNA levels were assessed by qRT-PCR. Molecular docking results demonstrated that the binding force between imperatorin and P-gp was much weaker than the force between P-gp and verapamil (a P-gp substrate). Imperatorin activated P-gp ATPase activity; which had a role in the inhibition of P-gp activity. Imperatorin promoted Rh-123 accumulation in MDCK-MDR1 cells and decreased cellular membrane fluidity. Western blotting demonstrated that imperatorin inhibited P-gp expression; and qRT-PCR revealed that imperatorin down-regulated P-gp (MDR1) gene expression. Imperatorin decreased P-gp-mediated drug efflux by inhibiting P-gp activity and the expression of P-gp mRNA and protein. Our results suggest that imperatorin could down-regulate P-gp expression to overcome multidrug resistance in tumors. [Mh] Termos MeSH primário: Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo Furocumarinas/farmacologia Isoflavonas/metabolismo Preparações de Plantas/farmacologia Vincristina/metabolismo [Mh] Termos MeSH secundário: Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética Angelica/química Animais Transporte Biológico/efeitos dos fármacos Linhagem Celular Difenilexatrieno/química Cães Células Madin Darby de Rim Canino Simulação de Acoplamento Molecular RNA Mensageiro/biossíntese [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (ATP-Binding Cassette, Sub-Family B, Member 1); 0 (Furocoumarins); 0 (Isoflavones); 0 (Plant Preparations); 0 (RNA, Messenger); 1720-32-7 (Diphenylhexatriene); 5J49Q6B70F (Vincristine); K713N25C78 (imperatorin); Z9W8997416 (puerarin) [Em] Mês de entrada: 1704 [Cu] Atualização por classe: 171116 [Lr] Data última revisão: 171116 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161126 [St] Status: MEDLINE

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[PMID]: 27475296 [Au] Autor: do Canto AMTM; Robalo JR; Santos PD; Carvalho AJP; Ramalho JPP; Loura LMS [Ad] Endereço: Centro de Química de Évora e Departamento de Química, Escola de Ciências e Tecnologia, Colégio Luís Verney, Rua Romão Ramalho 59, P-7002-554 Évora, Portugal. [Ti] Título: Diphenylhexatriene membrane probes DPH and TMA-DPH: A comparative molecular dynamics simulation study. [So] Source: Biochim Biophys Acta;1858(11):2647-2661, 2016 Nov. [Is] ISSN: 0006-3002 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: Fluorescence spectroscopy and microscopy have been utilized as tools in membrane biophysics for decades now. Because phospholipids are non-fluorescent, the use of extrinsic membrane probes in this context is commonplace. Among the latter, 1,6-diphenylhexatriene (DPH) and its trimethylammonium derivative (TMA-DPH) have been extensively used. It is widely believed that, owing to its additional charged group, TMA-DPH is anchored at the lipid/water interface and reports on a bilayer region that is distinct from that of the hydrophobic DPH. In this study, we employ atomistic MD simulations to characterize the behavior of DPH and TMA-DPH in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and POPC/cholesterol (4:1) bilayers. We show that although the dynamics of TMA-DPH in these membranes is noticeably more hindered than that of DPH, the location of the average fluorophore of TMA-DPH is only ~3-4Å more shallow than that of DPH. The hindrance observed in the translational and rotational motions of TMA-DPH compared to DPH is mainly not due to significant differences in depth, but to the favorable electrostatic interactions of the former with electronegative lipid atoms instead. By revealing detailed insights on the behavior of these two probes, our results are useful both in the interpretation of past work and in the planning of future experiments using them as membrane reporters. [Mh] Termos MeSH primário: Colesterol/química Difenilexatrieno/análogos & derivados Difenilexatrieno/química Corantes Fluorescentes/química Simulação de Dinâmica Molecular Fosfatidilcolinas/química [Mh] Termos MeSH secundário: Fluorescência Polarização de Fluorescência Interações Hidrofóbicas e Hidrofílicas Bicamadas Lipídicas/química Fluidez de Membrana Eletricidade Estática Termodinâmica Água/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Fluorescent Dyes); 0 (Lipid Bilayers); 0 (Phosphatidylcholines); 059QF0KO0R (Water); 1720-32-7 (Diphenylhexatriene); 71316-28-4 (1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene); 97C5T2UQ7J (Cholesterol); TE895536Y5 (1-palmitoyl-2-oleoylphosphatidylcholine) [Em] Mês de entrada: 1706 [Cu] Atualização por classe: 170812 [Lr] Data última revisão: 170812 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160801 [St] Status: MEDLINE

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[PMID]: 27022833 [Au] Autor: Suga K; Akizaki K; Umakoshi H [Ad] Endereço: Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan. [Ti] Título: Quantitative Monitoring of Microphase Separation Behaviors in Cationic Liposomes Using HHC, DPH, and Laurdan: Estimation of the Local Electrostatic Potentials in Microdomains. [So] Source: Langmuir;32(15):3630-6, 2016 Apr 19. [Is] ISSN: 1520-5827 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Microphase separation behaviors of cationic liposomes have been investigated using a pH-sensitive fluorescent probe with 4-heptadecyl-7-hydroxycoumarin (HHC), 1,6-diphenyl-1,3,5-hexatriene, and 6-lauroyl-2-dimethylaminonaphthalene, and to estimate localized electrostatic potentials. Shifts of the apparent pKa values of HHC were observed in cationic liposomes in proportion to the amount of cationic lipids. Two pKa values were obtained with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/3ß-[N(N',N'-dimethylaminoethane)-carbamoyl] cholesterol hydrochloride (DC-Ch) liposomes, while only one pKa value was generated with either DOPC/1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) or DOPC/dimethyldioctadecylammonium-bromide (DODAB) liposomes. The physicochemical membrane property analyses, focusing on membrane fluidity and membrane polarity, revealed heterogeneity among DOPC/DC-Ch liposomes. By analyzing the pH titration curves using sigmoidal fitting, the localized electrostatic potentials were estimated. For DOPC/DOTAP = (7/3), the membrane was in the liquid-disordered phase and the density of cationic molecules was 0.41 cation/nm(2). For DOPC/DC-Ch = (7/3), the membrane was heterogeneous and the densities of cationic molecules in liquid-disordered and liquid-ordered phases were 0.25 and 1.24 cation/nm(2), respectively. We thereby conclude that the DC-Ch molecules can form nanodomains when these molecules are concentrated to 59%. [Mh] Termos MeSH primário: 2-Naftilamina/análogos & derivados Difenilexatrieno/química Corantes Fluorescentes/química Lauratos/química Lipossomos/química Umbeliferonas/química [Mh] Termos MeSH secundário: 2-Naftilamina/química Colesterol/análogos & derivados Colesterol/química Ácidos Graxos Monoinsaturados/química Concentração de Íons de Hidrogênio Fluidez de Membrana Fosfatidilcolinas/química Compostos de Amônio Quaternário/química Espectrometria de Fluorescência [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Fatty Acids, Monounsaturated); 0 (Fluorescent Dyes); 0 (Laurates); 0 (Liposomes); 0 (Phosphatidylcholines); 0 (Quaternary Ammonium Compounds); 0 (Umbelliferones); 137056-72-5 (3-(N-(N',N'-dimethylaminoethane)carbamoyl)cholesterol); 1720-32-7 (Diphenylhexatriene); 26038-83-5 (4-heptadecylumbelliferone); 97C5T2UQ7J (Cholesterol); CKR7XL41N4 (2-Naphthylamine); EDS2L3ODLV (1,2-oleoylphosphatidylcholine); MR86K0XRQP (1,2-dioleoyloxy-3-(trimethylammonium)propane); Y97FBL93VW (laurdan) [Em] Mês de entrada: 1706 [Cu] Atualização por classe: 171116 [Lr] Data última revisão: 171116 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160330 [St] Status: MEDLINE [do] DOI: 10.1021/acs.langmuir.5b04682

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[PMID]: 26456556 [Au] Autor: Neves AR; Nunes C; Reis S [Ad] Endereço: UCIBIO, REQUIMTE, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal. [Ti] Título: Resveratrol induces ordered domains formation in biomembranes: Implication for its pleiotropic action. [So] Source: Biochim Biophys Acta;1858(1):12-8, 2016 Jan. [Is] ISSN: 0006-3002 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: Resveratrol is a polyphenol compound with great value in cancer therapy, cardiovascular protection, and neurodegenerative disorders. The mechanism by which resveratrol exerts such pleiotropic effects is not yet clear and there is a huge need to understand the influence of this compound on the regulation of lipid domains formation on membrane structure. The aim of the present study was to reveal potential molecular interactions between resveratrol and lipid rafts found in cell membranes by means of Förster resonance energy transfer, DPH fluorescence quenching, and triton X-100 detergent resistance assay. Liposomes composed of egg phosphatidylcholine, cholesterol, and sphingomyelin were used as model membranes. The results revealed that resveratrol induces phase separation and formation of liquid-ordered domains in bilayer structures. The formation of such tightly packed lipid rafts is important for different signal transduction pathways, through the regulation of membrane-associating proteins, that can justify several pharmacological activities of this compound. [Mh] Termos MeSH primário: Bicamadas Lipídicas/química Lipossomos/química Microdomínios da Membrana/efeitos dos fármacos Estilbenos/farmacologia [Mh] Termos MeSH secundário: Animais Galinhas Colesterol/química Óxidos N-Cíclicos/química Difenilexatrieno/química Transferência Ressonante de Energia de Fluorescência Corantes Fluorescentes/química Microdomínios da Membrana/química Octoxinol/química Fosfatidilcolinas/química Esfingomielinas/química Estilbenos/química Termodinâmica [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Cyclic N-Oxides); 0 (Fluorescent Dyes); 0 (Lipid Bilayers); 0 (Liposomes); 0 (Phosphatidylcholines); 0 (Sphingomyelins); 0 (Stilbenes); 1720-32-7 (Diphenylhexatriene); 9002-93-1 (Octoxynol); 97C5T2UQ7J (Cholesterol); Q369O8926L (resveratrol); VQN7359ICQ (TEMPO) [Em] Mês de entrada: 1604 [Cu] Atualização por classe: 161126 [Lr] Data última revisão: 161126 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 151013 [St] Status: MEDLINE

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[PMID]: 26302022 [Au] Autor: Swain J; Kumar Mishra A [Ad] Endereço: Department of Chemistry, Indian Institute of Technology Madras , Chennai 600 036, India. [Ti] Título: Location, Partitioning Behavior, and Interaction of Capsaicin with Lipid Bilayer Membrane: Study Using Its Intrinsic Fluorescence. [So] Source: J Phys Chem B;119(36):12086-93, 2015 Sep 10. [Is] ISSN: 1520-5207 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Capsaicin is an ingredient of a wide variety of red peppers, and it has various pharmacological and biological applications. The present study explores the interaction of capsaicin with dimyristoylphosphatidylcholine (DMPC) lipid bilayer membrane by monitoring various photophysical parameters using its intrinsic fluorescence. In order to have a clearer understanding of the photophysical responses of capsaicin, studies involving (i) its solvation behavior in different solvents, (ii) the partition coefficient of capsaicin in different thermotropic phase states of lipid bilayer membrane, and (iii) its location inside lipid bilayer membrane have been carried out. Capsaicin has a reasonably high partition coefficient for DMPC liposome membrane, in both solid gel (2.8 ± 0.1 × 10(5)) and liquid crystalline (2.6 ± 0.1 × 10(5)) phases. Fluorescence quenching study using cetylpyridinium chloride (CPC) as quencher suggests that the phenolic group of capsaicin molecule is generally present near the headgroup region and hydrophobic tail present inside hydrophobic core region of the lipid bilayer membrane. The intrinsic fluorescence intensity and lifetime of capsaicin sensitively respond to the temperature dependent phase changes of liposome membrane. Above 15 mol %, capsaicin in the aqueous liposome suspension medium lowers the thermotropic phase transition temperature by about 3 °C, and above 30 mol %, the integrity of the membrane is significantly lost. [Mh] Termos MeSH primário: Capsaicina/química Membrana Celular/química Bicamadas Lipídicas/química [Mh] Termos MeSH secundário: Dimiristoilfosfatidilcolina/química Difenilexatrieno/química Lipossomos/química Modelos Moleculares Conformação Molecular Transição de Fase Espectrometria de Fluorescência Temperatura Ambiente [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Lipid Bilayers); 0 (Liposomes); 1720-32-7 (Diphenylhexatriene); S07O44R1ZM (Capsaicin); U86ZGC74V5 (Dimyristoylphosphatidylcholine) [Em] Mês de entrada: 1606 [Cu] Atualização por classe: 150911 [Lr] Data última revisão: 150911 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150825 [St] Status: MEDLINE [do] DOI: 10.1021/acs.jpcb.5b05351

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[PMID]: 26147344 [Au] Autor: Majumdar A; Kundu D; Sarkar M [Ad] Endereço: †Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064, India. [Ti] Título: Differential Effect of Oxicam Non-Steroidal Anti-Inflammatory Drugs on Membranes and Their Consequence on Membrane Fusion. [So] Source: J Phys Chem B;119(30):9627-39, 2015 Jul 30. [Is] ISSN: 1520-5207 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Non-steroidal anti-inflammatory drugs (NSAIDs) are the most commonly used analgesics and antipyretics, which form an interesting drug group because of their new and alternate functions. The ability of the NSAIDs belonging to the oxicam chemical group to induce membrane fusion at low physiologically relevant concentrations is a new function that has drawn considerable attention. Membrane fusion is dependent on the interplay of physicochemical properties of both drugs and membranes. Here, we have elucidated the effects of different oxicam drugs, Meloxicam, Piroxicam, Tenoxicam, Lornoxicam, and Isoxicam, on an identical membrane-mimetic system. This highlights only the differential effects of the drugs on drug-membrane interactions, which in turn modulate their role as membrane fusogens. The partitioning behavior and the location of the drugs in dimyristoylphosphatidylcholine vesicles have been studied using second-derivative absorption spectroscopy, fluorescence quenching, steady-state fluorescence anisotropy, and time-resolved fluorescence lifetime measurements. Fusion kinetics has been monitored by fluorescence assays and dynamic light scattering was used to provide a snapshot of the vesicle diameter distribution at different time points. The differential perturbing effect of the drugs on the membrane is dependent both on their partitioning and location. Although partitioning governs the extent of fusion, the location modulates the rates of each step. [Mh] Termos MeSH primário: Anti-Inflamatórios não Esteroides/farmacologia Membrana Celular/efeitos dos fármacos Membrana Celular/metabolismo Fusão de Membrana/efeitos dos fármacos Tiazinas/farmacologia [Mh] Termos MeSH secundário: Anisotropia Membrana Celular/química Difenilexatrieno/química Cinética Bicamadas Lipídicas/química Bicamadas Lipídicas/metabolismo Fluidez de Membrana/efeitos dos fármacos [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Anti-Inflammatory Agents, Non-Steroidal); 0 (Lipid Bilayers); 0 (Thiazines); 1720-32-7 (Diphenylhexatriene) [Em] Mês de entrada: 1605 [Cu] Atualização por classe: 150730 [Lr] Data última revisão: 150730 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150707 [St] Status: MEDLINE [do] DOI: 10.1021/acs.jpcb.5b03918

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[PMID]: 25843678 [Au] Autor: Wrobel D; Appelhans D; Signorelli M; Wiesner B; Fessas D; Scheler U; Voit B; Maly J [Ad] Endereço: Department of Biology, Jan Evangelista Purkinje University, Usti nad Labem, Czech Republic. Electronic address: dominika.wrobel@ujep.cz. [Ti] Título: Interaction study between maltose-modified PPI dendrimers and lipidic model membranes. [So] Source: Biochim Biophys Acta;1848(7):1490-501, 2015 Jul. [Is] ISSN: 0006-3002 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: The influence of maltose-modified poly(propylene imine) (PPI) dendrimers on dimyristoylphosphatidylcholine (DMPC) or dimyristoylphosphatidylcholine/dimyristoylphosphatidylglycerol (DMPC/DMPG) (3%) liposomes was studied. Fourth generation (G4) PPI dendrimers with primary amino surface groups were partially (open shell glycodendrimers - OS) or completely (dense shell glycodendrimers - DS) modified with maltose residues. As a model membrane, two types of 100nm diameter liposomes were used to observe differences in the interactions between neutral DMPC and negatively charged DMPC/DMPG bilayers. Interactions were studied using fluorescence spectroscopy to evaluate the membrane fluidity of both the hydrophobic and hydrophilic parts of the lipid bilayer and using differential scanning calorimetry to investigate thermodynamic parameter changes. Pulsed-filed gradient NMR experiments were carried out to evaluate common diffusion coefficient of DMPG and DS PPI in D2O when using below critical micelle concentration of DMPG. Both OS and DS PPI G4 dendrimers show interactions with liposomes. Neutral DS dendrimers exhibit stronger changes in membrane fluidity compared to OS dendrimers. The bilayer structure seems more rigid in the case of anionic DMPC/DMPG liposomes in comparison to pure and neutral DMPC liposomes. Generally, interactions of dendrimers with anionic DMPC/DMPG and neutral DMPC liposomes were at the same level. Higher concentrations of positively charged OS dendrimers induced the aggregation process with negatively charged liposomes. For all types of experiments, the presence of NaCl decreased the strength of the interactions between glycodendrimers and liposomes. Based on NMR diffusion experiments we suggest that apart from electrostatic interactions for OS PPI hydrogen bonds play a major role in maltose-modified PPI dendrimer interactions with anionic and neutral model membranes where a contact surface is needed for undergoing multiple H-bond interactions between maltose shell of glycodendrimers and surface membrane of liposome. [Mh] Termos MeSH primário: Dendrímeros/química Bicamadas Lipídicas/química Maltose/química Lipídeos de Membrana/química Polipropilenos/química [Mh] Termos MeSH secundário: Varredura Diferencial de Calorimetria Dendrímeros/metabolismo Dimiristoilfosfatidilcolina/química Dimiristoilfosfatidilcolina/metabolismo Difenilexatrieno/química Polarização de Fluorescência Ligações de Hidrogênio Interações Hidrofóbicas e Hidrofílicas Bicamadas Lipídicas/metabolismo Lipossomos/química Lipossomos/metabolismo Espectroscopia de Ressonância Magnética Maltose/metabolismo Fluidez de Membrana Lipídeos de Membrana/metabolismo Fosfatidilgliceróis/química Fosfatidilgliceróis/metabolismo Polipropilenos/metabolismo Eletricidade Estática [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Dendrimers); 0 (Lipid Bilayers); 0 (Liposomes); 0 (Membrane Lipids); 0 (Phosphatidylglycerols); 0 (Polypropylenes); 0 (poly(propyleneimine)); 1720-32-7 (Diphenylhexatriene); 69-79-4 (Maltose); BI71WT9P3R (dimyristoylphosphatidylglycerol); U86ZGC74V5 (Dimyristoylphosphatidylcholine) [Em] Mês de entrada: 1509 [Cu] Atualização por classe: 161126 [Lr] Data última revisão: 161126 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150407 [St] Status: MEDLINE

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