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Referências encontradas : 208 [refinar]
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[PMID]:29277370
[Au] Autor:Chand S; Ray S; Wanigasekara E; Yadav P; Crawford JA; Armstrong DW; Rajeshwar K; Pierce BS
[Ad] Endereço:Department of Chemistry and Biochemistry, The University of Texas at Arlington, Texas 76019, USA; Department of Biology, Catholic University of America, Washington DC 20064, USA.
[Ti] Título:Improved rate of substrate oxidation catalyzed by genetically-engineered myoglobin.
[So] Source:Arch Biochem Biophys;639:44-51, 2018 02 01.
[Is] ISSN:1096-0384
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:This study showcases the potential of unnatural amino acids to enable non-natural functions when incorporated in the protein scaffold of heme metalloproteins. For this purpose, a genetically-engineered myoglobin (Mb) mutant was created by incorporating redox-active 3-amino-l-tyrosine (NH Tyr) into its active site, replacing the distal histidine (H64) with NH Tyr. In peroxide-shunt assays, this variant exhibits an increased rate of turnover for thioanisole and benzaldehyde oxidation as compared to the wild-type (WT) Mb. Indeed, in the presence of excess hydrogen peroxide (H O ), a 9-fold and 81-fold increase in activity was observed over multiple turnovers for thioanisole sulfoxidation and benzoic acid formation, respectively. The increased oxidation activity in the H64NH Tyr Mb mutant underlined the role of NH Tyr in the distal active-site scaffold in peroxide activation. Kinetic, electrochemical, and EPR spectroscopic experiments were performed. On the basis of these studies, it is argued that the single NH Tyr residue within the Mb variant simultaneously serves the role of the conserved His/Arg-pair within the distal pocket of horseradish peroxidase.
[Mh] Termos MeSH primário: Substituição de Aminoácidos
Ácido Benzoico/química
Mioglobina/química
Sulfetos/química
[Mh] Termos MeSH secundário: Animais
Mutação de Sentido Incorreto
Mioglobina/genética
Oxirredução
Cachalote
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Myoglobin); 0 (Sulfides); 8SKN0B0MIM (Benzoic Acid); BB4K737YF4 (methylphenylsulfide)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180214
[Lr] Data última revisão:
180214
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171227
[St] Status:MEDLINE


  2 / 208 MEDLINE  
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[PMID]:28758387
[Au] Autor:Kanai Y; Harada A; Shibata T; Nishimura R; Namiki K; Watanabe M; Nakamura S; Yumoto F; Senda T; Suzuki A; Neya S; Yamamoto Y
[Ad] Endereço:Department of Chemistry, University of Tsukuba , Tsukuba 305-8571, Japan.
[Ti] Título:Characterization of Heme Orientational Disorder in a Myoglobin Reconstituted with a Trifluoromethyl-Group-Substituted Heme Cofactor.
[So] Source:Biochemistry;56(34):4500-4508, 2017 Aug 29.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The orientation of a CF -substituted heme in sperm whale myoglobin and L29F, H64L, L29F/H64Q, and H64Q variant proteins has been investigated using F NMR spectroscopy to elucidate structural factors responsible for the thermodynamic stability of the heme orientational disorder, i.e., the presence of two heme orientations differing by a 180° rotation about the 5-15 meso axis, with respect to the protein moiety. Crystal structure of the met-aquo form of the wild-type myoglobin reconstituted with 13,17-bis(2-carboxylatoethyl)-3,8-diethyl-2,12,18-trimethyl-7-trifluoromethylporphyrinatoiron(III), determined at resolution of 1.25 Å, revealed the presence of the heme orientational disorder. Alterations of the salt bridge between the heme 13-propionate and Arg45(CD3) side chains due to the mutations resulted in equilibrium constants of the heme orientational disorder ranging between 0.42 and 1.4. Thus, the heme orientational disorder is affected by the salt bridge associated with the heme 13-propionate side chain, confirming the importance of the salt bridge in the heme binding to the protein.
[Mh] Termos MeSH primário: Heme/química
Mutação de Sentido Incorreto
Mioglobina/química
[Mh] Termos MeSH secundário: Substituição de Aminoácidos
Animais
Sítios de Ligação
Cristalografia por Raios X
Heme/metabolismo
Mioglobina/genética
Mioglobina/metabolismo
Cachalote
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Myoglobin); 42VZT0U6YR (Heme)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170831
[Lr] Data última revisão:
170831
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170801
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00457


  3 / 208 MEDLINE  
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[PMID]:28606113
[Au] Autor:Alstrup AKO; Munk OL; Jensen TH; Jensen LF; Hedayat A; Hansen B
[Ad] Endereço:Department of Nuclear Medicine and PET Center, Institute of Clinical Medicine, Aarhus University Hospital, Nørrebrogade 44, 10C, 8000, Aarhus, Denmark. aagols@rm.dk.
[Ti] Título:Magnetic resonance imaging and computed tomography as tools for the investigation of sperm whale (Physeter macrocephalus) teeth and eye.
[So] Source:Acta Vet Scand;59(1):38, 2017 Jun 12.
[Is] ISSN:1751-0147
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Scanning techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) are useful tools in veterinary and human medicine. Here we demonstrate the usefulness of these techniques in the study of the anatomy of wild marine mammals as part of a necropsy. MRI and CT scans of sperm whale teeth (n = 4) were performed. The methods were compared and further compared to current standard methods for evaluation of tooth layering. For MRI a zero echo time sequence was used, as previously done for imaging of intact human teeth. For CT two different clinical scanners were used. RESULTS: The three scanners did not provide sufficient information to allow age estimation, but both MRI and CT provided anatomical information about the tooth cortex and medulla without the need for sectioning the teeth. MRI scanning was also employed for visualizing the vascularization of an intact eye from one of the stranded sperm whale. CONCLUSIONS: Clearly, MRI was useful for investigation of the retinal vasculation, but optimum results would require well-preserved tissue. It was not possible to estimate age based on CT scans of tooth growth lines. Further research is needed to clarify the usability of MRI and CT as tools for marine mammal research when samples need to remain intact or when a spatial (three dimensional) arrangement of features needs to be determined.
[Mh] Termos MeSH primário: Olho/anatomia & histologia
Cachalote/anatomia & histologia
Dente/anatomia & histologia
[Mh] Termos MeSH secundário: Animais
Olho/diagnóstico por imagem
Imagem por Ressonância Magnética/veterinária
Especificidade da Espécie
Tomografia Computadorizada por Raios X/veterinária
Dente/diagnóstico por imagem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171107
[Lr] Data última revisão:
171107
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170614
[St] Status:MEDLINE
[do] DOI:10.1186/s13028-017-0307-y


  4 / 208 MEDLINE  
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[PMID]:28601072
[Au] Autor:Balobanov VA; Katina NS; Finkelstein AV; Bychkova VE
[Ad] Endereço:Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia. uralm62@rambler.ru.
[Ti] Título:Intermediate States of Apomyoglobin: Are They Parts of the Same Area of Conformations Diagram?
[So] Source:Biochemistry (Mosc);82(5):625-631, 2017 May.
[Is] ISSN:1608-3040
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Several research teams have reported detection and characterization of various apomyoglobin intermediate states different in their accumulation mode, thus putting a natural question as to proportions of these intermediates. The current report presents spectral properties of sperm whale apomyoglobin studied over a wide range of conditions with the use of circular dichroism and fluorescence techniques. Based on the experimental data, a diagram of apomyoglobin conformational states has been constructed. It shows that though induced by various denaturants, all the observed intermediates belong to one and the same area in the diagram.
[Mh] Termos MeSH primário: Apoproteínas/química
Mioglobina/química
Desnaturação Proteica
Ureia/química
[Mh] Termos MeSH secundário: Animais
Dicroísmo Circular
Conformação Proteica
Cachalote
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Apoproteins); 0 (Myoglobin); 0 (apomyoglobin); 8W8T17847W (Urea)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170621
[Lr] Data última revisão:
170621
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170612
[St] Status:MEDLINE
[do] DOI:10.1134/S0006297917050108


  5 / 208 MEDLINE  
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[PMID]:28500397
[Au] Autor:Ackleh AS; Chiquet RA; Ma B; Tang T; Caswell H; Veprauskas A; Sidorovskaia N
[Ad] Endereço:Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA, 70504-1010, USA. ackleh@louisiana.edu.
[Ti] Título:Analysis of lethal and sublethal impacts of environmental disasters on sperm whales using stochastic modeling.
[So] Source:Ecotoxicology;26(6):820-830, 2017 Aug.
[Is] ISSN:1573-3017
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mathematical models are essential for combining data from multiple sources to quantify population endpoints. This is especially true for species, such as marine mammals, for which data on vital rates are difficult to obtain. Since the effects of an environmental disaster are not fixed, we develop time-varying (nonautonomous) matrix population models that account for the eventual recovery of the environment to the pre-disaster state. We use these models to investigate how lethal and sublethal impacts (in the form of reductions in the survival and fecundity, respectively) affect the population's recovery process. We explore two scenarios of the environmental recovery process and include the effect of demographic stochasticity. Our results provide insights into the relationship between the magnitude of the disaster, the duration of the disaster, and the probability that the population recovers to pre-disaster levels or a biologically relevant threshold level. To illustrate this modeling methodology, we provide an application to a sperm whale population. This application was motivated by the 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico that has impacted a wide variety of species populations including oysters, fish, corals, and whales.
[Mh] Termos MeSH primário: Monitoramento Ambiental
Modelos Teóricos
Cachalote/psicologia
Poluentes Químicos da Água/toxicidade
[Mh] Termos MeSH secundário: Animais
Desastres
Meio Ambiente
Peixes
Campos de Petróleo e Gás
Petróleo
Poluição por Petróleo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Petroleum); 0 (Water Pollutants, Chemical)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170514
[St] Status:MEDLINE
[do] DOI:10.1007/s10646-017-1813-4


  6 / 208 MEDLINE  
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[PMID]:28375148
[Au] Autor:Owen RL; Axford D; Sherrell DA; Kuo A; Ernst OP; Schulz EC; Miller RJ; Mueller-Werkmeister HM
[Ad] Endereço:Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
[Ti] Título:Low-dose fixed-target serial synchrotron crystallography.
[So] Source:Acta Crystallogr D Struct Biol;73(Pt 4):373-378, 2017 Apr 01.
[Is] ISSN:2059-7983
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The development of serial crystallography has been driven by the sample requirements imposed by X-ray free-electron lasers. Serial techniques are now being exploited at synchrotrons. Using a fixed-target approach to high-throughput serial sampling, it is demonstrated that high-quality data can be collected from myoglobin crystals, allowing room-temperature, low-dose structure determination. The combination of fixed-target arrays and a fast, accurate translation system allows high-throughput serial data collection at high hit rates and with low sample consumption.
[Mh] Termos MeSH primário: Cristalografia por Raios X/instrumentação
Mioglobina/química
[Mh] Termos MeSH secundário: Animais
Cristalização/instrumentação
Desenho de Equipamento
Dispositivos Lab-On-A-Chip
Modelos Moleculares
Cachalote
Síncrotrons
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Myoglobin)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171106
[Lr] Data última revisão:
171106
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170405
[St] Status:MEDLINE
[do] DOI:10.1107/S2059798317002996


  7 / 208 MEDLINE  
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[PMID]:28274434
[Au] Autor:Grunwald EW; Tatiyaborworntham N; Faustman C; Richards MP
[Ad] Endereço:Meat Science and Muscle Biology Laboratory, Department of Animal Sciences, University of Wisconsin-Madison, Madison, WI 53706, United States.
[Ti] Título:Effect of 4-hydroxy-2-nonenal on myoglobin-mediated lipid oxidation when varying histidine content and hemin affinity.
[So] Source:Food Chem;227:289-297, 2017 Jul 15.
[Is] ISSN:0308-8146
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The compound 4-hydroxy-2-nonenal (HNE) dissolved in water was examined to remove potential effects of using ethanol to solubilize the aldehyde such as altering protein structure or redox properties of myoglobin (Mb). HNE became covalently bound to sperm whale Mb at up to five sites based on ESI-MS analysis. Adducted Mb promoted lipid oxidation in washed muscle more effectively than non-adducted Mb. Alkylation of P88H/Q152HMb with HNE accelerated metMb formation and subsequent lipid oxidation. P88H/Q152HMb exposed to HNE enhanced lipid oxidation compared to wild-type Mb exposed to HNE. Results using H97A Mb suggested that the combination of HNE and low hemin affinity facilitated rapid decomposition of preformed lipid hydroperoxides to secondary lipid oxidation products. HNE and HHE (4-hydroxy-2-hexenal) facilitated Mb-mediated lipid oxidation similarly. The potential mechanisms by which Mb binding of α,ß-unsaturated aldehydes affect Mb oxidation and the onset of lipid oxidation are discussed.
[Mh] Termos MeSH primário: Aldeídos/metabolismo
Hemina/metabolismo
Histidina/metabolismo
Metabolismo dos Lipídeos
Mioglobina/metabolismo
[Mh] Termos MeSH secundário: Animais
Hemina/química
Histidina/química
Cinética
Lipídeos/química
Músculos/química
Músculos/metabolismo
Mioglobina/química
Mioglobina/genética
Oxirredução
Cachalote
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Aldehydes); 0 (Lipids); 0 (Myoglobin); 4QD397987E (Histidine); 743LRP9S7N (Hemin); K1CVM13F96 (4-hydroxy-2-nonenal)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170501
[Lr] Data última revisão:
170501
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170310
[St] Status:MEDLINE


  8 / 208 MEDLINE  
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[PMID]:27706153
[Au] Autor:Gero S; Whitehead H
[Ad] Endereço:Zoophysiology, Institute for Bioscience, Aarhus University, Aarhus, Denmark.
[Ti] Título:Critical Decline of the Eastern Caribbean Sperm Whale Population.
[So] Source:PLoS One;11(10):e0162019, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Sperm whale (Physeter macrocephalus) populations were expected to rebuild following the end of commercial whaling. We document the decline of the population in the eastern Caribbean by tracing demographic changes of well-studied social units. We address hypotheses that, over a ten-year period of dedicated effort (2005-2015), unit size, numbers of calves and/or calving rates have each declined. Across 16 units, the number of adults decreased in 12 units, increased in two, and showed no change in two. The number of adults per unit decreased at -0.195 individuals/yr (95% CI: -0.080 to -0.310; P = 0.001). The number of calves also declined, but the decline was not significant. This negative trend of -4.5% per year in unit size started in about 2010, with numbers being fairly stable until then. There are several natural and anthropogenic threats, but no well-substantiated cause for the decline.
[Mh] Termos MeSH primário: Cachalote/fisiologia
[Mh] Termos MeSH secundário: Animais
Região do Caribe
Fotometria
Densidade Demográfica
Cachalote/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170620
[Lr] Data última revisão:
170620
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161006
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0162019


  9 / 208 MEDLINE  
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[PMID]:27539635
[Au] Autor:Unger B; Rebolledo ELB; Deaville R; Gröne A; IJsseldijk LL; Leopold MF; Siebert U; Spitz J; Wohlsein P; Herr H
[Ad] Endereço:Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation. Werftstr. 6, 25761 Büsum, Germany.
[Ti] Título:Large amounts of marine debris found in sperm whales stranded along the North Sea coast in early 2016.
[So] Source:Mar Pollut Bull;112(1-2):134-141, 2016 Nov 15.
[Is] ISSN:1879-3363
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:30 sperm whales (Physeter macrocephalus) stranded along the coasts of the North Sea between January and February 2016. The gastro-intestinal tracts of 22 of the carcasses were investigated. Marine debris including netting, ropes, foils, packaging material and a part of a car were found in nine of the 22 individuals. Here we provide details about the findings and consequences for the animals. While none of the items was responsible for the death of the animal, the findings demonstrate the high level of exposure to marine debris and associated risks for large predators, such as the sperm whale.
[Mh] Termos MeSH primário: Monitoramento Ambiental
Plásticos/análise
Cachalote/metabolismo
Resíduos/análise
Poluentes da Água/análise
[Mh] Termos MeSH secundário: Animais
Masculino
Mar do Norte
Plásticos/metabolismo
Poluentes da Água/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Plastics); 0 (Waste Products); 0 (Water Pollutants)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170917
[Lr] Data última revisão:
170917
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160820
[St] Status:MEDLINE


  10 / 208 MEDLINE  
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[PMID]:27487825
[Au] Autor:Oghbaey S; Sarracini A; Ginn HM; Pare-Labrosse O; Kuo A; Marx A; Epp SW; Sherrell DA; Eger BT; Zhong Y; Loch R; Mariani V; Alonso-Mori R; Nelson S; Lemke HT; Owen RL; Pearson AR; Stuart DI; Ernst OP; Mueller-Werkmeister HM; Miller RJ
[Ad] Endereço:Department of Physics and Chemistry, University of Toronto, 60 St George Street, Toronto, ON M5S 1A7, Canada.
[Ti] Título:Fixed target combined with spectral mapping: approaching 100% hit rates for serial crystallography.
[So] Source:Acta Crystallogr D Struct Biol;72(Pt 8):944-55, 2016 08.
[Is] ISSN:2059-7983
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The advent of ultrafast highly brilliant coherent X-ray free-electron laser sources has driven the development of novel structure-determination approaches for proteins, and promises visualization of protein dynamics on sub-picosecond timescales with full atomic resolution. Significant efforts are being applied to the development of sample-delivery systems that allow these unique sources to be most efficiently exploited for high-throughput serial femtosecond crystallography. Here, the next iteration of a fixed-target crystallography chip designed for rapid and reliable delivery of up to 11 259 protein crystals with high spatial precision is presented. An experimental scheme for predetermining the positions of crystals in the chip by means of in situ spectroscopy using a fiducial system for rapid, precise alignment and registration of the crystal positions is presented. This delivers unprecedented performance in serial crystallography experiments at room temperature under atmospheric pressure, giving a raw hit rate approaching 100% with an effective indexing rate of approximately 50%, increasing the efficiency of beam usage and allowing the method to be applied to systems where the number of crystals is limited.
[Mh] Termos MeSH primário: Cristalização/métodos
Cristalografia por Raios X/métodos
Proteínas/química
[Mh] Termos MeSH secundário: Animais
Cristalização/economia
Cristalização/instrumentação
Cristalografia por Raios X/economia
Cristalografia por Raios X/instrumentação
Desenho de Equipamento
Mioglobina/química
Cachalote
Temperatura Ambiente
Fatores de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Myoglobin); 0 (Proteins)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171117
[Lr] Data última revisão:
171117
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160805
[St] Status:MEDLINE
[do] DOI:10.1107/S2059798316010834



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