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Pesquisa : D12.776.543.750.720.200 [Categoria DeCS]
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[PMID]:27045856
[Au] Autor:Li YH; Li FN; Wu L; Liu YY; Wei HK; Li TJ; Tan BE; Kong XF; Wu F; Duan YH; Oladele OA; Yin YL
[Ad] Endereço:Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Ch
[Ti] Título:Reduced dietary protein level influences the free amino acid and gene expression profiles of selected amino acid transceptors in skeletal muscle of growing pigs.
[So] Source:J Anim Physiol Anim Nutr (Berl);101(1):96-104, 2017 Feb.
[Is] ISSN:1439-0396
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:This study was conducted to evaluate the effect of reduced dietary protein level on growth performance, muscle mass weight, free amino acids (FAA) and gene expression profile of selected amino acid transceptors in different fibre type of skeletal muscle tissues (longissimus dorsi, psoas major, biceps femoris) of growing pigs. A total of 18 cross-bred growing pigs (Large White × Landrace × Duroc) with initial body weight (9.57 ± 0.67 kg) were assigned into three dietary treatments: 20% crude protein (CP) diet (normal recommended, NP), 17% CP diet (low protein, LP) and 14% CP diet (very low protein, VLP). The results indicated improved feed-to-gain ratio was obtained for pigs fed LP and NP diets (p < 0.01), while the pigs fed VLP diet showed the worst growth performance (p < 0.01). There was no significant difference in the weights of longissimus dorsi and psoas major muscle between LP and NP groups (p > 0.05). Majority of the determined FAA concentration of LP group were greater than or equal to those of NP group in both longissimus dorsi and psoas major muscle (p < 0.01). Further, the mRNA expression levels of sodium-coupled neutral amino acid transceptor 2, L-type amino acid transceptor 1 and proton-assisted amino acid transceptors 2 were higher in skeletal muscle tissue in LP group compared to those of the pigs fed NP or VLP diet. These results suggested that reduced dietary protein level (3 points of percentage less than recommended level) would upregulate the mRNA expression of amino acid transceptors to enhance the absorption of FAA in skeletal muscle of growing pigs. There seems to be a relationship between response of AA transceptors to the dietary protein level in skeletal muscle tissue of different fibre type. To illustrate the underlying mechanisms will be beneficial to animal nutrition.
[Mh] Termos MeSH primário: Aminoácidos/metabolismo
Proteínas na Dieta/administração & dosagem
Receptores de Aminoácido/metabolismo
Suínos/crescimento & desenvolvimento
Transcriptoma
[Mh] Termos MeSH secundário: Ração Animal/análise
Fenômenos Fisiológicos da Nutrição Animal
Animais
Dieta/veterinária
Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Receptores de Aminoácido/genética
Suínos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acids); 0 (Dietary Proteins); 0 (RNA, Messenger); 0 (Receptors, Amino Acid)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170811
[Lr] Data última revisão:
170811
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160406
[St] Status:MEDLINE
[do] DOI:10.1111/jpn.12514


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[PMID]:27292793
[Au] Autor:Mise T
[Ad] Endereço:2-19-3 Misato, Okinawa-shi, Okinawa 904-2153, Japan.
[Ti] Título:Structural Analysis of the Ligand-Binding Domain of the Aspartate Receptor Tar from Escherichia coli.
[So] Source:Biochemistry;55(26):3708-13, 2016 Jul 05.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The Escherichia coli cell-surface aspartate receptor Tar mediates bacterial chemotaxis toward an attractant, aspartate (Asp), and away from a repellent, Ni(2+). These signals are transmitted from the extracellular region of Tar to the cytoplasmic region via the transmembrane domain. The mechanism by which extracellular signals are transmitted into the cell through conformational changes in Tar is predicted to involve a piston displacement of one of the α4 helices of the homodimer. To understand the molecular mechanisms underlying the induction of Tar activity by an attractant, the three-dimensional structures of the E. coli Tar periplasmic domain with and without bound aspartate, Asp-Tar and apo-Tar, respectively, were determined. Of the two ligand-binding sites, only one site was occupied, and it clearly showed the electron density of an aspartate. The slight changes in conformation and the electrostatic surface potential around the aspartate-binding site were observed. In addition, the presence of an aspartate stabilized residues Phe-150' and Arg-73. A pistonlike displacement of helix α4b' was also induced by aspartate binding as predicted by the piston model. Taken together, these small changes might be related to the induction of Tar activity and might disturb binding of the second aspartate to the second binding site in E. coli.
[Mh] Termos MeSH primário: Ácido Aspártico/metabolismo
Proteínas de Escherichia coli/química
Escherichia coli/metabolismo
Receptores de Aminoácido/química
Receptores de Superfície Celular/química
[Mh] Termos MeSH secundário: Sítios de Ligação
Quimiotaxia
Proteínas de Escherichia coli/metabolismo
Modelos Moleculares
Conformação Proteica
Receptores de Aminoácido/metabolismo
Receptores de Superfície Celular/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Receptors, Amino Acid); 0 (Receptors, Cell Surface); 0 (Tar protein, E coli); 0 (aspartic acid receptor); 30KYC7MIAI (Aspartic Acid)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170502
[Lr] Data última revisão:
170502
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160614
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.6b00160


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[PMID]:27031335
[Au] Autor:Schwarzer C; Fischer H; Machen TE
[Ad] Endereço:Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America.
[Ti] Título:Chemotaxis and Binding of Pseudomonas aeruginosa to Scratch-Wounded Human Cystic Fibrosis Airway Epithelial Cells.
[So] Source:PLoS One;11(3):e0150109, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Confocal imaging was used to characterize interactions of Pseudomonas aeruginosa (PA, expressing GFP or labeled with Syto 11) with CF airway epithelial cells (CFBE41o-, grown as confluent monolayers with unknown polarity on coverglasses) in control conditions and following scratch wounding. Epithelia and PAO1-GFP or PAK-GFP (2 MOI) were incubated with Ringer containing typical extracellular salts, pH and glucose and propidium iodide (PI, to identify dead cells). PAO1 and PAK swam randomly over and did not bind to nonwounded CFBE41o- cells. PA migrated rapidly (began within 20 sec, maximum by 5 mins) and massively (10-80 fold increase, termed "swarming"), but transiently (random swimming after 15 mins), to wounds, particularly near cells that took up PI. Some PA remained immobilized on cells near the wound. PA swam randomly over intact CFBE41o- monolayers and wounded monolayers that had been incubated with medium for 1 hr. Expression of CFTR and altered pH of the media did not affect PA interactions with CFBE41o- wounds. In contrast, PAO1 swarming and immobilization along wounds was abolished in PAO1 (PAO1ΔcheYZABW, no expression of chemotaxis regulatory components cheY, cheZ, cheA, cheB and cheW) and greatly reduced in PAO1 that did not express amino acid receptors pctA, B and C (PAO1ΔpctABC) and in PAO1 incubated in Ringer containing a high concentration of mixed amino acids. Non-piliated PAKΔpilA swarmed normally towards wounded areas but bound infrequently to CFBE41o- cells. In contrast, both swarming and binding of PA to CFBE41o- cells near wounds were prevented in non-flagellated PAKΔfliC. Data are consistent with the idea that (i) PA use amino acid sensor-driven chemotaxis and flagella-driven swimming to swarm to CF airway epithelial cells near wounds and (ii) PA use pili to bind to epithelial cells near wounds.
[Mh] Termos MeSH primário: Aderência Bacteriana/fisiologia
Fibrose Cística/patologia
Pseudomonas aeruginosa/fisiologia
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Linhagem Celular
Quimiotaxia
Fibrose Cística/metabolismo
Regulador de Condutância Transmembrana em Fibrose Cística/genética
Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo
Células Epiteliais/citologia
Células Epiteliais/metabolismo
Seres Humanos
Proteínas de Membrana/deficiência
Proteínas de Membrana/genética
Microscopia de Fluorescência
Microscopia de Vídeo
Pseudomonas aeruginosa/genética
Receptores de Aminoácido/deficiência
Receptores de Aminoácido/genética
Mucosa Respiratória/citologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Membrane Proteins); 0 (Receptors, Amino Acid); 126880-72-6 (Cystic Fibrosis Transmembrane Conductance Regulator)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:160415
[Lr] Data última revisão:
160415
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160401
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0150109


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[PMID]:26923153
[Au] Autor:Machuca MA; Liu YC; Beckham SA; Gunzburg MJ; Roujeinikova A
[Ad] Endereço:Infection and Immunity Program, Monash Biomedicine Discovery Institute, Australia; Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia.
[Ti] Título:The crystal structure of the tandem-PAS sensing domain of Campylobacter jejuni chemoreceptor Tlp1 suggests indirect mechanism of ligand recognition.
[So] Source:J Struct Biol;194(2):205-13, 2016 May.
[Is] ISSN:1095-8657
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Chemotaxis and motility play an important role in the colonisation of avian and human hosts by Campylobacter jejuni. Chemotactic recognition of extracellular signals is mediated by the periplasmic sensing domain of methyl-accepting chemotactic proteins (membrane-embedded receptors). In this work, we report a high-resolution structure of the periplasmic sensing domain of transducer-like protein 1 (Tlp1), an aspartate receptor of C. jejuni. Crystallographic analysis revealed that it contains two Per-Arnt-Sim (PAS) subdomains. An acetate and chloride ions (both from the crystallisation buffer) were observed bound to the membrane-proximal and membrane-distal PAS subdomains, respectively. Surprisingly, despite being crystallised in the presence of aspartate, the structure did not show any electron density corresponding to this amino acid. Furthermore, no binding between the sensing domain of Tlp1 and aspartate was detected by microcalorimetric experiments. These structural and biophysical data suggest that Tlp1 does not sense aspartate directly; instead, ligand recognition is likely to occur indirectly via an as yet unidentified periplasmic binding protein.
[Mh] Termos MeSH primário: Ácido Aspártico/química
Proteínas de Bactérias/química
Campylobacter jejuni/química
Receptores de Aminoácido/química
[Mh] Termos MeSH secundário: Ácido Aspártico/metabolismo
Proteínas de Bactérias/metabolismo
Campylobacter jejuni/metabolismo
Quimiotaxia/fisiologia
Cristalografia por Raios X
Ligantes
Modelos Moleculares
Domínios Proteicos
Estrutura Secundária de Proteína
Receptores de Aminoácido/metabolismo
Proteínas Recombinantes/química
Proteínas Recombinantes/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Ligands); 0 (Receptors, Amino Acid); 0 (Recombinant Proteins); 0 (aspartic acid receptor); 30KYC7MIAI (Aspartic Acid)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160301
[St] Status:MEDLINE


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[PMID]:26878914
[Au] Autor:Nishiyama S; Takahashi Y; Yamamoto K; Suzuki D; Itoh Y; Sumita K; Uchida Y; Homma M; Imada K; Kawagishi I
[Ad] Endereço:Department of Frontier Bioscience, Hosei University, Kajino-cho, Koganei, Tokyo 184-8584, Japan.
[Ti] Título:Identification of a Vibrio cholerae chemoreceptor that senses taurine and amino acids as attractants.
[So] Source:Sci Rep;6:20866, 2016 Feb 16.
[Is] ISSN:2045-2322
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Vibrio cholerae, the etiological agent of cholera, was found to be attracted by taurine (2-aminoethanesulfonic acid), a major constituent of human bile. Mlp37, the closest homolog of the previously identified amino acid chemoreceptor Mlp24, was found to mediate taxis to taurine as well as L-serine, L-alanine, L-arginine, and other amino acids. Methylation of Mlp37 was enhanced upon the addition of taurine and amino acids. Isothermal titration calorimetry demonstrated that a purified periplasmic fragment of Mlp37 binds directly to taurine, L-serine, L-alanine and L-arginine. Crystal structures of the periplamic domain of Mlp37 revealed that L-serine and taurine bind to the membrane-distal PAS domain in essentially in the same way. The structural information was supported by characterising the in vivo properties of alanine-substituted mutant forms of Mlp37. The fact that the ligand-binding domain of the L-serine complex had a small opening, which would accommodate a larger R group, accounts for the broad ligand specificity of Mlp37 and allowed us to visualise ligand binding to Mlp37 with fluorescently labelled L-serine. Taken together, we conclude that Mlp37 serves as the major chemoreceptor for taurine and various amino acids.
[Mh] Termos MeSH primário: Receptores de Aminoácido/metabolismo
Receptores de Neurotransmissores/metabolismo
Vibrio cholerae/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Bile/química
Fatores Quimiotáticos
Quimiotaxia
Ligantes
Modelos Moleculares
Mutação
Ligação Proteica
Conformação Proteica
Receptores de Aminoácido/química
Receptores de Aminoácido/genética
Receptores de Neurotransmissores/química
Receptores de Neurotransmissores/genética
Taurina/química
Vibrio cholerae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Chemotactic Factors); 0 (Ligands); 0 (Receptors, Amino Acid); 0 (Receptors, Neurotransmitter); 0 (taurine receptor); 1EQV5MLY3D (Taurine)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160217
[St] Status:MEDLINE
[do] DOI:10.1038/srep20866


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[PMID]:25754253
[Au] Autor:Nair SS; Prathibha P; Syam Das S; Kavitha S; Indira M
[Ad] Endereço:Department of Biochemistry, University of Kerala, Kariavattom, Thiruvananthapuram-695 581, Kerala, India.
[Ti] Título:All trans retinoic acid (ATRA) mediated modulation of N-methyl D-aspartate receptor (NMDAR) and Kruppel like factor 11 (KLF11) expressions in the mitigation of ethanol induced alterations in the brain.
[So] Source:Neurochem Int;83-84:41-7, 2015 Apr-May.
[Is] ISSN:1872-9754
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Damaging effects that chronic ethanol exposure causes to the brain and the neurons are well documented. Ethanol and its toxic metabolites increase the oxidative stress in brain. Chronic exposure to ethanol leads to upregulation of N-methyl D-aspartate receptors (NMDAR) and also activates Kruppel like factor 11 (KLF11) mediated death cascade and thereby neurodegeneration. OBJECTIVE: Ethanol depletes vitamin A stores. But supplementation of vitamin A exacerbates ethanol induced toxicity since alcohol and its metabolites are competitive inhibitors of the enzymes involved in the metabolism of vitamin A. Hence, in this study we investigated the impact of co-administration of ethanol and all trans retinoic acid (ATRA), active metabolite of vitamin A, on ethanol induced alterations to the brain. MATERIALS AND METHODS: Male Sprague Dawley rats, adolescent, were grouped as follows and maintained for 90 days. I - Control, II - Ethanol (4 g/kg b.w.), III - ATRA (100 µg/kg b.w.), IV - Ethanol (4 g/kg b.w.), +ATRA (100 µg/kg b.w.). Oxidative stress and the mRNA expression of various receptors for the neurotransmitter involved in glutamergic, serotonergic and gabaergic pathways were studied in the brain homogenate. RESULTS: Ethanol treatment was shown to decrease brain weight and it was increased on ATRA treatment. Increase in oxidative stress due to ethanol treatment was also brought down on ATRA administration. Ethanol induced upregulation of NMDAR and KLF11 was also downregulated on ATRA supplementation. The alterations in the levels of neurotransmitters and the expression of their receptors due to ethanol treatment also were ameliorated on ATRA supplementation. CONCLUSION: Our results show that ATRA supplementation mitigates the ethanol induced alterations in the brain by reducing oxidative stress in the brain with concurrent suppression of NMDAR and KLF11 expression leading to enhanced catabolism of neurotransmitters.
[Mh] Termos MeSH primário: Encéfalo/efeitos dos fármacos
Etanol/farmacologia
Receptores de N-Metil-D-Aspartato/metabolismo
Transativadores/metabolismo
Tretinoína/metabolismo
[Mh] Termos MeSH secundário: Animais
Encéfalo/metabolismo
Masculino
Estresse Oxidativo/efeitos dos fármacos
Ratos
Receptores de Aminoácido/metabolismo
Vitamina A/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Receptors, Amino Acid); 0 (Receptors, N-Methyl-D-Aspartate); 0 (TIEG2 protein, rat); 0 (Trans-Activators); 0 (aspartic acid receptor); 11103-57-4 (Vitamin A); 3K9958V90M (Ethanol); 5688UTC01R (Tretinoin)
[Em] Mês de entrada:1605
[Cu] Atualização por classe:150414
[Lr] Data última revisão:
150414
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150311
[St] Status:MEDLINE


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[PMID]:25195895
[Au] Autor:Mise T; Matsunami H; Samatey FA; Maruyama IN
[Ad] Endereço:Information Processing Biology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami, Okinawa 904-0495, Japan.
[Ti] Título:Crystallization and preliminary X-ray diffraction analysis of the periplasmic domain of the Escherichia coli aspartate receptor Tar and its complex with aspartate.
[So] Source:Acta Crystallogr F Struct Biol Commun;70(Pt 9):1219-23, 2014 Sep.
[Is] ISSN:2053-230X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The cell-surface receptor Tar mediates bacterial chemotaxis toward an attractant, aspartate (Asp), and away from a repellent, Ni(2+). To understand the molecular mechanisms underlying the induction of Tar activity by its ligands, the Escherichia coli Tar periplasmic domain with and without bound aspartate (Asp-Tar and apo-Tar, respectively) were each crystallized in two different forms. Using ammonium sulfate as a precipitant, crystals of apo-Tar1 and Asp-Tar1 were grown and diffracted to resolutions of 2.10 and 2.40 Å, respectively. Alternatively, using sodium chloride as a precipitant, crystals of apo-Tar2 and Asp-Tar2 were grown and diffracted to resolutions of 1.95 and 1.58 Å, respectively. Crystals of apo-Tar1 and Asp-Tar1 adopted space group P41212, while those of apo-Tar2 and Asp-Tar2 adopted space groups P212121 and C2, respectively.
[Mh] Termos MeSH primário: Ácido Aspártico/química
Proteínas de Bactérias/química
Escherichia coli/química
Periplasma/química
Receptores de Aminoácido/química
[Mh] Termos MeSH secundário: Sequência de Bases
Cristalização
Cristalografia por Raios X
Primers do DNA
Plasmídeos
Reação em Cadeia da Polimerase
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA Primers); 0 (Receptors, Amino Acid); 0 (aspartic acid receptor); 30KYC7MIAI (Aspartic Acid)
[Em] Mês de entrada:1505
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140909
[St] Status:MEDLINE
[do] DOI:10.1107/S2053230X14014733


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[PMID]:24841754
[Au] Autor:Sal-Man N; Gerber D; Shai Y
[Ad] Endereço:Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel; Department of Microbiology and Immunology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. Electronic address: salmanne@bgu.ac.il.
[Ti] Título:Proline localized to the interaction interface can mediate self-association of transmembrane domains.
[So] Source:Biochim Biophys Acta;1838(9):2313-8, 2014 Sep.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Assembly of transmembrane domains (TMDs) is a critical step in the function of membrane proteins. In recent years, the role of specific amino acids in TMD-TMD interactions has been better characterized, with more emphasis on polar and aromatic residues. Despite the high abundance of proline residues in TMDs, contribution of proline to TMD-TMD association has not been intensively studied. Here, we evaluated statistically the frequency of appearance, and experimentally the contribution of proline, compared to other hydrophobic amino acids (Gly, Ala, Val, Leu, Ile, and Met), with regard to TMD-TMD self-assembly. Our model system is the assembly motif ((22)QxxS(25)) found previously in TMDs of the Escherichia coli aspartate receptor (Tar-1). Statistically, our data revealed that all different motifs, except PxxS (P/S), have frequencies similar to their theoretical random expectancy within a database of 41916 sequences of TMDs, while PxxS motif is underrepresented. Experimentally, using the ToxR assembly system, the SDS-gel running pattern of biotin-conjugated TMD peptides, and FRET experiments between fluorescence-labeled peptides, we found that only the P/S motif preserves the dimerization ability of wild-type Tar-1 TMD. Although proline is known as a helix breaker in solution, Circular Dichroism spectroscopy revealed that the secondary structure of the P/S and the wild-type peptides are similar. All together, these data suggest that proline can stabilize TM self-assembly when localized to the interaction interface of a transmembrane oligomer. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.
[Mh] Termos MeSH primário: Membrana Celular/química
Proteínas de Membrana/química
Prolina/química
Estrutura Terciária de Proteína
[Mh] Termos MeSH secundário: Motivos de Aminoácidos/genética
Dimerização
Escherichia coli/química
Isoleucina/química
Prolina/genética
Estrutura Secundária de Proteína
Receptores de Aminoácido/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Membrane Proteins); 0 (Receptors, Amino Acid); 0 (aspartic acid receptor); 04Y7590D77 (Isoleucine); 9DLQ4CIU6V (Proline)
[Em] Mês de entrada:1409
[Cu] Atualização por classe:161126
[Lr] Data última revisão:
161126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140521
[St] Status:MEDLINE


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[PMID]:24274333
[Au] Autor:Koshy SS; Eyles SJ; Weis RM; Thompson LK
[Ad] Endereço:Department of Chemistry, ‡Department of Biochemistry and Molecular Biology, and §Program in Molecular and Cellular Biology, University of Massachusetts , Amherst, Massachusetts 01003, United States.
[Ti] Título:Hydrogen exchange mass spectrometry of functional membrane-bound chemotaxis receptor complexes.
[So] Source:Biochemistry;52(49):8833-42, 2013 Dec 10.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The transmembrane signaling mechanism of bacterial chemotaxis receptors is thought to involve changes in receptor conformation and dynamics. The receptors function in ternary complexes with two other proteins, CheA and CheW, that form extended membrane-bound arrays. Previous studies have shown that attractant binding induces a small (∼2 Å) piston displacement of one helix of the periplasmic and transmembrane domains toward the cytoplasm, but it is not clear how this signal propagates through the cytoplasmic domain to control the kinase activity of the CheA bound at the membrane-distal tip, nearly 200 Å away. The cytoplasmic domain has been shown to be highly dynamic, which raises the question of how a small piston motion could propagate through a dynamic domain to control CheA kinase activity. To address this, we have developed a method for measuring dynamics of the receptor cytoplasmic fragment (CF) in functional complexes with CheA and CheW. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) measurements of global exchange of the CF demonstrate that the CF exhibits significantly slower exchange in functional complexes than in solution. Because the exchange rates in functional complexes are comparable to those of other proteins with similar structures, the CF appears to be a well-structured protein within these complexes, which is compatible with its role in propagating a signal that appears to be a tiny conformational change in the periplasmic and transmembrane domains of the receptor. We also demonstrate the feasibility of this protocol for local exchange measurements by incorporating a pepsin digest step to produce peptides with 87% sequence coverage and only 20% back exchange. This method extends HDX-MS to membrane-bound functional complexes without detergents that may perturb the stability or structure of the system.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Proteínas de Escherichia coli/química
Escherichia coli
Proteínas de Membrana/química
Receptores de Aminoácido/química
[Mh] Termos MeSH secundário: Quimiotaxia
Medição da Troca de Deutério
Histidina Quinase
Cinética
Membranas Artificiais
Proteínas Quimiotáticas Aceptoras de Metil
Peso Molecular
Multimerização Proteica
Soluções
Espectrometria de Massas em Tandem
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (CheW protein, E coli); 0 (Escherichia coli Proteins); 0 (Membrane Proteins); 0 (Membranes, Artificial); 0 (Methyl-Accepting Chemotaxis Proteins); 0 (Receptors, Amino Acid); 0 (Solutions); 0 (aspartic acid receptor); EC 2.7.13.1 (Histidine Kinase); EC 2.7.13.3 (cheA protein, E coli)
[Em] Mês de entrada:1402
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:131127
[St] Status:MEDLINE
[do] DOI:10.1021/bi401261b


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[PMID]:23799472
[Au] Autor:Amiry-Moghaddam M; Ottersen OP
[Ad] Endereço:Laboratory of Molecular Neuroscience, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
[Ti] Título:Immunogold cytochemistry in neuroscience.
[So] Source:Nat Neurosci;16(7):798-804, 2013 Jul.
[Is] ISSN:1546-1726
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The complexity of the central nervous system calls for immunocytochemical procedures that allow target proteins to be localized with high precision and with opportunities for quantitation. Immunogold procedures stand out as particularly powerful in this regard. Although these procedures have found wide application in the neuroscience community, they present limitations and pitfalls that must be taken into account. At the same time, these procedures offer potentials that remain to be fully realized.
[Mh] Termos MeSH primário: Histocitoquímica
Imuno-Histoquímica/métodos
Neurônios/ultraestrutura
Neurociências
[Mh] Termos MeSH secundário: Animais
Seres Humanos
Imuno-Histoquímica/instrumentação
Neurônios/metabolismo
Neurotransmissores/metabolismo
Receptores de Aminoácido/metabolismo
Receptores de Aminoácido/ultraestrutura
Sinapses/metabolismo
Sinapses/ultraestrutura
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Neurotransmitter Agents); 0 (Receptors, Amino Acid)
[Em] Mês de entrada:1309
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130627
[St] Status:MEDLINE
[do] DOI:10.1038/nn.3418



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