Base de dados : MEDLINE
Pesquisa : D08.811.520.224.600 [Categoria DeCS]
Referências encontradas : 1714 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 172 ir para página                         

  1 / 1714 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28468827
[Au] Autor:Zhao L; Fan J; Xia S; Pan Y; Liu S; Qian G; Qian Z; Kang HB; Arbiser JL; Pollack BP; Kudchadkar RR; Lawson DH; Rossi M; Abdel-Wahab O; Merghoub T; Khoury HJ; Khuri FR; Boise LH; Lonial S; Chen F; Chen J; Lin R
[Ad] Endereço:From the Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory, Emory University School of Medicine, Atlanta, Georgia 30322.
[Ti] Título:HMG-CoA synthase 1 is a synthetic lethal partner of BRAF in human cancers.
[So] Source:J Biol Chem;292(24):10142-10152, 2017 06 16.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Contributions of metabolic changes to cancer development and maintenance have received increasing attention in recent years. Although many human cancers share similar metabolic alterations, it remains unclear whether oncogene-specific metabolic alterations are required for tumor development. Using an RNAi-based screen targeting the majority of the known metabolic proteins, we recently found that oncogenic BRAF up-regulates HMG-CoA lyase (HMGCL), which converts HMG-CoA to acetyl-CoA and a ketone body, acetoacetate, that selectively enhances BRAF -dependent MEK1 activation in human cancer. Here, we identified HMG-CoA synthase 1 (HMGCS1), the upstream ketogenic enzyme of HMGCL, as an additional "synthetic lethal" partner of BRAF Although HMGCS1 expression did not correlate with BRAF mutation in human melanoma cells, HMGCS1 was selectively important for proliferation of BRAF -positive melanoma and colon cancer cells but not control cells harboring active N/KRAS mutants, and stable knockdown of HMGCS1 only attenuated colony formation and tumor growth potential of BRAF melanoma cells. Moreover, cytosolic HMGCS1 that co-localized with HMGCL and BRAF was more important than the mitochondrial HMGCS2 isoform in BRAF -expressing cancer cells in terms of acetoacetate production. Interestingly, HMGCL knockdown did not affect HMGCS1 expression levels, whereas HMGCS1 knockdown caused a compensating increase in HMGCL protein level because of attenuated protein degradation. However, this increase did not reverse the reduced ketogenesis in HMGCS1 knockdown cells. Mechanistically, HMGCS1 inhibition decreased intracellular acetoacetate levels, leading to reduced BRAF -MEK1 binding and consequent MEK1 activation. We conclude that the ketogenic HMGCS1-HMGCL-acetoacetate axis may represent a promising therapeutic target for managing BRAF -positive human cancers.
[Mh] Termos MeSH primário: Neoplasias do Colo/enzimologia
Hidroximetilglutaril-CoA Sintase/metabolismo
MAP Quinase Quinase 1/metabolismo
Melanoma/enzimologia
Proteínas de Neoplasias/metabolismo
Oxo-Ácido-Liases/metabolismo
Proteínas Proto-Oncogênicas B-raf/metabolismo
[Mh] Termos MeSH secundário: Acetoacetatos/metabolismo
Substituição de Aminoácidos
Animais
Linhagem Celular Tumoral
Proliferação Celular
Neoplasias do Colo/metabolismo
Neoplasias do Colo/patologia
Citosol/enzimologia
Citosol/metabolismo
Ativação Enzimática
Estabilidade Enzimática
Feminino
Seres Humanos
Hidroximetilglutaril-CoA Sintase/antagonistas & inibidores
Hidroximetilglutaril-CoA Sintase/genética
Isoenzimas/antagonistas & inibidores
Isoenzimas/genética
Isoenzimas/metabolismo
MAP Quinase Quinase 1/química
Melanoma/metabolismo
Melanoma/patologia
Camundongos Nus
Mutação
Proteínas de Neoplasias/antagonistas & inibidores
Proteínas de Neoplasias/química
Proteínas de Neoplasias/genética
Transplante de Neoplasias
Oxo-Ácido-Liases/antagonistas & inibidores
Oxo-Ácido-Liases/química
Oxo-Ácido-Liases/genética
Proteólise
Proteínas Proto-Oncogênicas B-raf/genética
Interferência de RNA
Carga Tumoral
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Acetoacetates); 0 (Isoenzymes); 0 (Neoplasm Proteins); 4ZI204Y1MC (acetoacetic acid); EC 2.3.3.10 (HMGCS1 protein, human); EC 2.3.3.10 (Hydroxymethylglutaryl-CoA Synthase); EC 2.7.11.1 (BRAF protein, human); EC 2.7.11.1 (Proto-Oncogene Proteins B-raf); EC 2.7.12.2 (MAP Kinase Kinase 1); EC 2.7.12.2 (MAP2K1 protein, human); EC 4.1.3.- (Oxo-Acid-Lyases); EC 4.1.3.4 (3-hydroxy-3-methylglutaryl-coenzyme A lyase)
[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:170505
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.788778


  2 / 1714 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28956599
[Au] Autor:Reddick JJ; Sirkisoon S; Dahal RA; Hardesty G; Hage NE; Booth WT; Quattlebaum AL; Mills SN; Meadows VG; Adams SLH; Doyle JS; Kiel BE
[Ad] Endereço:Department of Chemistry and Biochemistry, University of North Carolina at Greensboro , Greensboro, North Carolina 27402, United States.
[Ti] Título:First Biochemical Characterization of a Methylcitric Acid Cycle from Bacillus subtilis Strain 168.
[So] Source:Biochemistry;56(42):5698-5711, 2017 Oct 24.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The genome of Bacillus subtilis strain 168 contains the mother cell metabolic gene (mmg) operon that encodes homologues from the methylcitric acid cycle. We showed that the three genes, mmgDE and yqiQ(mmgF), provide three of the five steps of the methylcitric acid cycle. We also showed that the fourth step can be supplied by citB (aconitase), and we suggest that the fifth missing step, the propionyl-CoA synthetase, is probably skipped because the ß-oxidation of methyl-branched fatty acids by the enzymes encoded by mmgABC should produce propionyl-CoA. We also noted interesting enzymology for MmgD and MmgE. First, MmgD is a bifunctional citrate synthase/2-methylcitrate synthase with 2.3-fold higher activity as a 2-methylcitrate synthase. This enzyme catalyzes the formation of either (2S,3R)- or (2R,3S)-2-methylcitrate, but reports of 2-methylcitrate synthases from other species indicated that they produced the (2S,3S) isomer. However, we showed that MmgD and PrpC (from Escherichia coli) in fact produce the same stereoisomer. Second, the MmgE enzyme is not a stereospecific 2-methylcitrate dehydratase because it can dehydrate at least two of the four diastereomers of 2-methylcitrate to yield either (E)-2-methylaconitate or (Z)-2-methylaconitate. We also showed for the first time that the E. coli homologue PrpD exhibited the same lack of stereospecificity. However, the physiological pathways proceed via (Z)-2-methylaconitate, which served as the substrate for the citB enzyme in the synthesis of 2-methylisocitrate. We completed our characterization of this pathway by showing that the 2-methylisocitrate produced by CitB is converted to pyruvate and succinate by the enzyme YqiQ(MmgF).
[Mh] Termos MeSH primário: Bacillus subtilis/metabolismo
Citratos/metabolismo
Óperon/fisiologia
Oxo-Ácido-Liases/metabolismo
[Mh] Termos MeSH secundário: Bacillus subtilis/genética
Escherichia coli/genética
Escherichia coli/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Hidroliases/genética
Hidroliases/metabolismo
Oxirredução
Oxo-Ácido-Liases/genética
Estereoisomerismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Citrates); 0 (Escherichia coli Proteins); 6061-96-7 (2-methylcitric acid); EC 2.3.3.5 (2-methylcitrate synthase); EC 4.1.3.- (Oxo-Acid-Lyases); EC 4.2.1.- (Hydro-Lyases); EC 4.2.1.79 (methylcitrate dehydratase, E coli)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170929
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00778


  3 / 1714 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28791861
[Au] Autor:Wang Z; Zhuang W; Cheng J; Sun W; Wu J; Chen Y; Ying H
[Ad] Endereço:State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University , No. 5 Xinmofan Road, Nanjing 210009, China.
[Ti] Título:In Vivo Multienzyme Complex Coconstruction of N-Acetylneuraminic Acid Lyase and N-Acetylglucosamine-2-epimerase for Biosynthesis of N-Acetylneuraminic Acid.
[So] Source:J Agric Food Chem;65(34):7467-7475, 2017 Aug 30.
[Is] ISSN:1520-5118
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Metabolic channeling enables efficient transfer of the intermediates by forming a multienzyme complex. To leverage the metabolic channeling for improved biosynthesis, we coexpressed N-acetylneuraminic acid lyase from C. glutamicum ATCC 13032 (CgNal) and N-acetylglucosamine-2-epimerase from Anabaena sp. CH1 (anAGE) in Escherichia coli and used the whole cell to synthesize N-acetylneuraminic acid (Neu5Ac) from N-acetylglucosamine (GlcNAc) and pyruvate. To get the multienzyme complex, polycistronic plasmid with high levels of CgNal and anAGE expression was constructed by tuning the orders of the genes. The Shine-Dalgarno (SD) sequence and aligned spacing (AS) distance were optimized. The E. coli Rosetta harboring the polycistronic plasmid pET-28a-SD -AS -CgNal-SD-AS-anAGE increased the production of Neu5Ac by 58.7% to 92.5 g/L in 36 h by whole-cell catalysis and by 21.9% up to 112.8 g/L in 24 h with the addition of Triton X-100.
[Mh] Termos MeSH primário: Anabaena/enzimologia
Proteínas de Bactérias/metabolismo
Corynebacterium glutamicum/enzimologia
Oxo-Ácido-Liases/metabolismo
Racemases e Epimerases/metabolismo
[Mh] Termos MeSH secundário: Acetilglucosamina/metabolismo
Proteínas de Bactérias/genética
Estabilidade Enzimática
Escherichia coli/genética
Escherichia coli/metabolismo
Expressão Gênica
Oxo-Ácido-Liases/química
Oxo-Ácido-Liases/genética
Racemases e Epimerases/química
Racemases e Epimerases/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); EC 4.1.3.- (Oxo-Acid-Lyases); EC 4.1.3.3 (N-acetylneuraminate lyase); EC 5.1.- (Racemases and Epimerases); V956696549 (Acetylglucosamine)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170915
[Lr] Data última revisão:
170915
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170810
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jafc.7b02708


  4 / 1714 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28578265
[Au] Autor:Ouattara HD; Ouattara HG; Droux M; Reverchon S; Nasser W; Niamke SL
[Ad] Endereço:Laboratoire de Biotechnologies, UFR Biosciences, Université Félix HOUPHOUET-BOIGNY Abidjan, 22 bp 582 Abidjan, Côte d'Ivoire; Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon1, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois, F-69622 Villeurbanne, France.
[Ti] Título:Lactic acid bacteria involved in cocoa beans fermentation from Ivory Coast: Species diversity and citrate lyase production.
[So] Source:Int J Food Microbiol;256:11-19, 2017 Sep 01.
[Is] ISSN:1879-3460
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Microbial fermentation is an indispensable process for high quality chocolate from cocoa bean raw material. lactic acid bacteria (LAB) are among the major microorganisms responsible for cocoa fermentation but their exact role remains to be elucidated. In this study, we analyzed the diversity of LAB in six cocoa producing regions of Ivory Coast. Ribosomal 16S gene sequence analysis showed that Lactobacillus plantarum and Leuconostoc mesenteroides are the dominant LAB species in these six regions. In addition, other species were identified as the minor microbial population, namely Lactobacillus curieae, Enterococcus faecium, Fructobacillus pseudoficulneus, Lactobacillus casei, Weissella paramesenteroides and Weissella cibaria. However, in each region, the LAB microbial population was composed of a restricted number of species (maximum 5 species), which varied between the different regions. LAB implication in the breakdown of citric acid was investigated as a fundamental property for a successful cocoa fermentation process. High citrate lyase producer strains were characterized by rapid citric acid consumption, as revealed by a 4-fold decrease in citric acid concentration in the growth medium within 12h, concomitant with an increase in acetic acid and lactic acid concentration. The production of citrate lyase was strongly dependent on environmental conditions, with optimum production at acidic pH (pH<5), and moderate temperature (30-40°C), which corresponds to conditions prevailing in the early stage of natural cocoa fermentation. This study reveals that one of the major roles of LAB in the cocoa fermentation process involves the breakdown of citric acid during the early stage of cocoa fermentation through the activity of citrate lyase.
[Mh] Termos MeSH primário: Cacau/microbiologia
Ácido Cítrico/metabolismo
Fermentação/fisiologia
Lactobacillus plantarum/metabolismo
Leuconostoc mesenteroides/metabolismo
Complexos Multienzimáticos/metabolismo
Oxo-Ácido-Liases/metabolismo
[Mh] Termos MeSH secundário: Ácido Acético/metabolismo
Chocolate
Costa do Marfim
Meios de Cultura/metabolismo
Ácido Láctico/metabolismo
Lactobacillus plantarum/classificação
Lactobacillus plantarum/genética
Lactobacillus plantarum/isolamento & purificação
Leuconostoc mesenteroides/classificação
Leuconostoc mesenteroides/genética
Leuconostoc mesenteroides/isolamento & purificação
Complexos Multienzimáticos/biossíntese
Oxo-Ácido-Liases/biossíntese
RNA Ribossômico 16S/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Culture Media); 0 (Multienzyme Complexes); 0 (RNA, Ribosomal, 16S); 2968PHW8QP (Citric Acid); 33X04XA5AT (Lactic Acid); EC 4.1.3.- (Oxo-Acid-Lyases); EC 4.1.3.6 (citrate (pro-3S)-lyase); Q40Q9N063P (Acetic Acid)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170605
[St] Status:MEDLINE


  5 / 1714 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28381263
[Au] Autor:Tao W; Lv L; Chen GQ
[Ad] Endereço:School of Life Sciences, Tsinghua University, Beijing, 100084, China.
[Ti] Título:Engineering Halomonas species TD01 for enhanced polyhydroxyalkanoates synthesis via CRISPRi.
[So] Source:Microb Cell Fact;16(1):48, 2017 Apr 06.
[Is] ISSN:1475-2859
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Clustered regularly interspaced short palindromic repeats interference (CRISPRi) has provided an efficient approach for targeted gene inhibition. A non-model microorganism Halomonas species TD01 has been developed as a promising industrial producer of polyhydroxyalkanoates (PHA), a family of biodegradable polyesters accumulated by bacteria as a carbon and energy reserve compound. A controllable gene repression system, such as CRISPRi, is needed for Halomonas sp. TD01 to regulate its gene expression levels. RESULTS: For the first time CRISPRi was successfully used in Halomonas sp. TD01 to repress expression of ftsZ gene encoding bacterial fission ring formation protein, leading to an elongated cell morphology with typical filamentous shape similar to phenomenon observed with Escherichia coli. CRISPRi was employed to regulate expressions of prpC gene encoding 2-methylcitrate synthase for regulating 3-hydroxyvalerate monomer ratio in PHBV copolymers of 3-hydroxybutyrate (HB) and 3-hydroxyvalerate (HV). Percentages of HV in PHBV copolymers were controllable ranging from less than 1 to 13%. Furthermore, repressions on gltA gene encoding citrate synthase channeled more acetyl-CoA from the tricarboxylic acid (TCA) cycle to poly(3-hydroxybutyrate) (PHB) synthesis. The PHB accumulation by Halomonas sp. TD01 with its gltA gene repressed in various intensities via CRISPRi was increased by approximately 8% compared with the wild type control containing the CRISPRi vector without target. CONCLUSIONS: It has now been confirmed that the CRISPRi system can be applied to Halomonas sp. TD01, a promising industrial strain for production of various PHA and chemicals under open and continuous fermentation process conditions. In details, the CRISPRi system was successfully designed in this study to target genes of ftsZ, prpC and gltA, achieving longer cell sizes, channeling more substrates to PHBV and PHB synthesis, respectively. CRISPRi can be expected to use for more metabolic engineering applications in non-model organisms.
[Mh] Termos MeSH primário: Sistemas CRISPR-Cas
Halomonas/genética
Engenharia Metabólica/métodos
Poli-Hidroxialcanoatos/biossíntese
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Citrato (si)-Sintase/genética
Proteínas do Citoesqueleto/genética
Inativação Gênica
Halomonas/metabolismo
Hidroxibutiratos/metabolismo
Oxo-Ácido-Liases/genética
Poliésteres/metabolismo
Poli-Hidroxialcanoatos/metabolismo
Biologia Sintética/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Cytoskeletal Proteins); 0 (FtsZ protein, Bacteria); 0 (Hydroxybutyrates); 0 (Polyesters); 0 (Polyhydroxyalkanoates); 0 (poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate)); 26063-00-3 (poly-beta-hydroxybutyrate); EC 2.3.3.1 (Citrate (si)-Synthase); EC 2.3.3.5 (2-methylcitrate synthase); EC 4.1.3.- (Oxo-Acid-Lyases)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170424
[Lr] Data última revisão:
170424
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170407
[St] Status:MEDLINE
[do] DOI:10.1186/s12934-017-0655-3


  6 / 1714 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28349380
[Au] Autor:Szemiako K; Sledzinska A; Krawczyk B
[Ad] Endereço:Department of Molecular Biotechnology and Microbiology, Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland.
[Ti] Título:A new assay based on terminal restriction fragment length polymorphism of homocitrate synthase gene fragments for Candida species identification.
[So] Source:J Appl Genet;58(3):409-414, 2017 Aug.
[Is] ISSN:2190-3883
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Candida sp. have been responsible for an increasing number of infections, especially in patients with immunodeficiency. Species-specific differentiation of Candida sp. is difficult in routine diagnosis. This identification can have a highly significant association in therapy and prophylaxis. This work has shown a new application of the terminal restriction fragment length polymorphism (t-RFLP) method in the molecular identification of six species of Candida, which are the most common causes of fungal infections. Specific for fungi homocitrate synthase gene was chosen as a molecular target for amplification. The use of three restriction enzymes, DraI, RsaI, and BglII, for amplicon digestion can generate species-specific fluorescence labeled DNA fragment profiles, which can be used to determine the diagnostic algorithm. The designed method can be a cost-efficient high-throughput molecular technique for the identification of six clinically important Candida species.
[Mh] Termos MeSH primário: Candida/genética
Oxo-Ácido-Liases/genética
Polimorfismo de Fragmento de Restrição
[Mh] Termos MeSH secundário: Candida/enzimologia
DNA Fúngico/genética
Genes Fúngicos
Especificidade da Espécie
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Fungal); EC 2.3.3.14 (homocitrate synthase); EC 4.1.3.- (Oxo-Acid-Lyases)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170814
[Lr] Data última revisão:
170814
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170329
[St] Status:MEDLINE
[do] DOI:10.1007/s13353-017-0394-5


  7 / 1714 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28263400
[Au] Autor:Dong L; Liu Y
[Ad] Endereço:School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong, 250100, China.
[Ti] Título:Comparative studies of the catalytic mechanisms of two chorismatases: CH-fkbo and CH-Hyg5.
[So] Source:Proteins;85(6):1146-1158, 2017 Jun.
[Is] ISSN:1097-0134
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Chorismatase is an important enzyme involved in Shikimate pathway, which catalyzes the conversion of chorismate into pyruvate and (dihydro)-benzoic acid derivatives. According to the outcomes of catalytic reactions, chorismatases can be divided into three subfamilies: CH-Fkbo, CH-Hyg5 and CH-XanB2. Recently, the crystal structures of CH-Fkbo and CH-Hyg5 from Streptomyces hygroscopicus have been successfully obtained, allowing us to perform QM/MM calculations to explore the reaction details. Our calculation results support the proposal that CH-Fkbo and CH-Hyg5 employ different catalytic mechanisms and gave the mechanistic details. Fkbo follows a typical hydrolytic mechanism, which contains three consecutive steps, including the protonation step of the methylene group of substrate, the nucleophilic attack of the resulted carbocation by activated water and cleavage of C2'-O8 bond of tetrahedral intermediate (hemiketal). The protonation of methylene group and the C2'-O8 cleavage correspond to similar energy barriers (26.5 and 24.8 kcal/mol), suggesting both steps to be rate-limiting. Whereas Hyg5 employs an intramolecular mechanism, in which the oxygen from C4 migrates to C3 via an arene oxide intermediate. The first step of Hyg5, which corresponds to the concerted protonation of methylene group and the cleavage of C3-O8, is calculated to be rate-limiting with an energy barrier of 26.3 kcal/mol. The nonconserved active site residue G240 (or A244 °) is suggested to be responsible for leading to different reaction mechanism in CH-Fkbo and CH-Hyg5. During the catalytic reaction, residue C327 plays an important role in directing the product selectivity in Hyg5 enzyme. Proteins 2017; 85:1146-1158. © 2017 Wiley Periodicals, Inc.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Ácido Corísmico/química
Oxo-Ácido-Liases/química
Prótons
Ácido Pirúvico/química
Streptomyces/enzimologia
[Mh] Termos MeSH secundário: Alanina/química
Alanina/metabolismo
Motivos de Aminoácidos
Proteínas de Bactérias/metabolismo
Biocatálise
Domínio Catalítico
Ácido Corísmico/metabolismo
Cisteína/química
Cisteína/metabolismo
Glicina/química
Glicina/metabolismo
Hidrólise
Cinética
Modelos Moleculares
Oxo-Ácido-Liases/metabolismo
Ácido Pirúvico/metabolismo
Teoria Quântica
Streptomyces/química
Relação Estrutura-Atividade
Termodinâmica
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Protons); 8558G7RUTR (Pyruvic Acid); EC 4.1.3.- (Oxo-Acid-Lyases); EC 4.1.3.- (chorismate pyruvate lyase); GI1BLY82Y1 (Chorismic Acid); K848JZ4886 (Cysteine); OF5P57N2ZX (Alanine); TE7660XO1C (Glycine)
[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:170307
[St] Status:MEDLINE
[do] DOI:10.1002/prot.25279


  8 / 1714 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27920298
[Au] Autor:Borjian F; Han J; Hou J; Xiang H; Zarzycki J; Berg IA
[Ad] Endereço:Mikrobiologie, Fakultät Biologie, Universität Freiburg, Freiburg, Germany.
[Ti] Título:Malate Synthase and ß-Methylmalyl Coenzyme A Lyase Reactions in the Methylaspartate Cycle in Haloarcula hispanica.
[So] Source:J Bacteriol;199(4), 2017 Feb 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Haloarchaea are extremely halophilic heterotrophic microorganisms belonging to the class Halobacteria (Euryarchaeota). Almost half of the haloarchaea possesses the genes coding for enzymes of the methylaspartate cycle, a recently discovered anaplerotic acetate assimilation pathway. In this cycle, the enzymes of the tricarboxylic acid cycle together with the dedicated enzymes of the methylaspartate cycle convert two acetyl coenzyme A (acetyl-CoA) molecules to malate. The methylaspartate cycle involves two reactions catalyzed by homologous enzymes belonging to the CitE-like enzyme superfamily, malyl-CoA lyase/thioesterase (haloarchaeal malate synthase [hMS]; Hah_2476 in Haloarcula hispanica) and ß-methylmalyl-CoA lyase (haloarchaeal ß-methylmalyl-CoA lyase [hMCL]; Hah_1341). Although both enzymes catalyze the same reactions, hMS was previously proposed to preferentially catalyze the formation of malate from acetyl-CoA and glyoxylate (malate synthase activity) and hMCL was proposed to primarily cleave ß-methylmalyl-CoA to propionyl-CoA and glyoxylate. Here we studied the physiological functions of these enzymes during acetate assimilation in H. hispanica by using biochemical assays of the wild type and deletion mutants. Our results reveal that the main physiological function of hMS is malyl-CoA (not malate) formation and that hMCL catalyzes a ß-methylmalyl-CoA lyase reaction in vivo The malyl-CoA thioesterase activities of both enzymes appear to be not essential for growth on acetate. Interestingly, despite the different physiological functions of hMS and hMCL, structural comparisons predict that these two proteins have virtually identical active sites, thus highlighting the need for experimental validation of their catalytic functions. Our results provide further proof of the operation of the methylaspartate cycle and indicate the existence of a distinct, yet-to-be-discovered malyl-CoA thioesterase in haloarchaea. IMPORTANCE: Acetate is one of the most important substances in natural environments. The activated form of acetate, acetyl coenzyme A (acetyl-CoA), is the high-energy intermediate at the crossroads of central metabolism: its oxidation generates energy for the cell, and about a third of all biosynthetic fluxes start directly from acetyl-CoA. Many organic compounds enter the central carbon metabolism via this key molecule. To sustain growth on acetyl-CoA-generating compounds, a dedicated assimilation (anaplerotic) pathway is required. The presence of an anaplerotic pathway is a prerequisite for growth in many environments, being important for environmentally, industrially, and clinically important microorganisms. Here we studied specific reactions of a recently discovered acetate assimilation pathway, the methylaspartate cycle, functioning in extremely halophilic archaea.
[Mh] Termos MeSH primário: Ácido Aspártico/análogos & derivados
Regulação da Expressão Gênica em Archaea/fisiologia
Regulação Enzimológica da Expressão Gênica/fisiologia
Haloarcula/enzimologia
Malato Sintase/metabolismo
Oxo-Ácido-Liases/metabolismo
[Mh] Termos MeSH secundário: Ácido Aspártico/metabolismo
Extratos Celulares
Haloarcula/genética
Haloarcula/metabolismo
Malato Sintase/genética
Mutação
Oxo-Ácido-Liases/genética
Filogenia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cell Extracts); 30KYC7MIAI (Aspartic Acid); EC 2.3.3.9 (Malate Synthase); EC 4.1.3.- (Oxo-Acid-Lyases); EC 4.1.3.- (beta-methylmalyl-coenzyme A lyase)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170815
[Lr] Data última revisão:
170815
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161207
[St] Status:MEDLINE


  9 / 1714 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27848098
[Au] Autor:Cheng J; Zhuang W; Tang C; Chen Y; Wu J; Guo T; Ying H
[Ad] Endereço:State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, No. 5, Xinmofan Road, Nanjing, 210009, People's Republic of China.
[Ti] Título:Efficient immobilization of AGE and NAL enzymes onto functional amino resin as recyclable and high-performance biocatalyst.
[So] Source:Bioprocess Biosyst Eng;40(3):331-340, 2017 Mar.
[Is] ISSN:1615-7605
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:N-Acetylglucosamine-2-epimerase (AGE) and N-acetylneuraminic acid lyase (NAL) were immobilized for synthesis of N-acetylneuraminic acid (Neu5Ac) on three resins: Amberzyme oxirane resin (AOR), poly (styrene-co-DVB)-Br resin (PBR) and amino resin (AR). The loading capacity and immobilized enzyme activity showed that AR was the best carrier. Three methods of glutaraldehyde cross-linking were tested and simultaneous cross-linking and immobilization was demonstrated to be the best method. The functional properties of immobilized AGE and NAL were studied and compared to those of the free enzyme. The highest enzyme activities of free and immobilized AGE were obtained in 0.1 M potassium phosphate buffer at pH 7.5 and a temperature of 37 °C. Comparatively, the highest NAL activities were at pH 8.5. Meanwhile, an increase in K (from 1.14 to 1.31 mg·mL for AGE and from 1.05 to 1.25 mg·mL for NAL) and a decrease in V (from 177.53 to 106.37 µg·min mL for AGE and from 126.41 to 95.96 µg·min mL for NAL) were recorded after immobilization. The AR-glutaraldehyde-enzyme system exhibited better thermal stability than the free enzyme, and retained 72% of its initial activity even after eight repeated runs. The apparent activation energy (E ) of the free and immobilized AGE (NAL) was 117.14 kJ·mol (124.21 kJ·mol ) and 78.45 kJ·mol (66.64 kJ·mol ), respectively, implying that the catalytic efficiency of the immobilized enzyme was restricted by mass-transfer rather than kinetic limit. Subsequently, Neu5Ac production from GlcNAc using immobilized enzymes in one reactor was carried out resulting 101.45 g·L of Neu5Ac and the highest conversion ratio of 82%. This method of enzyme immobilization may have a promising future for Neu5Ac production in industry.
[Mh] Termos MeSH primário: Carboidratos Epimerases/química
Enzimas Imobilizadas/química
Liases/química
Ácido N-Acetilneuramínico/química
Oxo-Ácido-Liases/química
Racemases e Epimerases/química
[Mh] Termos MeSH secundário: Acetilglucosamina
Tampões (Química)
Catálise
Reagentes para Ligações Cruzadas/química
Compostos de Epóxi/química
Escherichia coli/enzimologia
Glutaral/química
Concentração de Íons de Hidrogênio
Cinética
Ácidos Neuramínicos/química
Fosfatos/química
Compostos de Potássio/química
Reprodutibilidade dos Testes
Resinas Sintéticas
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Buffers); 0 (Cross-Linking Reagents); 0 (Enzymes, Immobilized); 0 (Epoxy Compounds); 0 (Neuraminic Acids); 0 (Phosphates); 0 (Potassium Compounds); 0 (Resins, Synthetic); B7862WZ632 (potassium phosphate); EC 4.- (Lyases); EC 4.1.3.- (Oxo-Acid-Lyases); EC 4.1.3.3 (N-acetylneuraminate lyase); EC 5.1.- (Racemases and Epimerases); EC 5.1.3.- (Carbohydrate Epimerases); GZP2782OP0 (N-Acetylneuraminic Acid); T3C89M417N (Glutaral); V956696549 (Acetylglucosamine)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170317
[Lr] Data última revisão:
170317
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161117
[St] Status:MEDLINE
[do] DOI:10.1007/s00449-016-1700-z


  10 / 1714 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27742850
[Au] Autor:Richard E; Blouin JM; Harambat J; Llanas B; Bouchet S; Acquaviva C; de la Faille R
[Ad] Endereço:1 Biothérapies des Maladies Génétiques, Inflammatoires et Cancers, Université de Bordeaux, Bordeaux, France.
[Ti] Título:Late diagnosis of primary hyperoxaluria type III.
[So] Source:Ann Clin Biochem;54(3):406-411, 2017 May.
[Is] ISSN:1758-1001
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We report the case of a 78-year-old patient with late diagnosis of hyperoxaluria type III (PH3). He developed renal failure after nephrectomy for clear cell papillary renal carcinoma and complained of recurrent urolithiasis for some 30 years, whose aetiology was never identified. Biochemical laboratory investigations of urine and urolithiasis composition revealed marked hyperoxaluria but normal concentrations of urinary glyceric and glycolic acid as well as stones of idiopathic calcium-oxalate appearance. Furthermore, the dietary survey showed excessive consumption of food supplements containing massive amounts of oxalate precursors. However, the persistence of excessive hyperoxaluria after his eating habits was changed leading us to perform molecular genetic testing. We found heterozygous mutations of the recently PH3-associated HOGA1 gene when sequencing PH genes. This is the first description of late diagnosis primary PH3 in a patient with several additional pro-lithogenic factors. This case illustrates the importance of undertaking a complete biological work-up to determine the aetiology of hyperoxaluria. This may reveal underdiagnosed primary hyperoxaluria, even in older patients.
[Mh] Termos MeSH primário: Diagnóstico Tardio
Hiperoxalúria Primária/diagnóstico
Mutação
Oxo-Ácido-Liases/genética
Urolitíase/diagnóstico
[Mh] Termos MeSH secundário: Idoso
Carcinoma de Células Renais/diagnóstico
Carcinoma de Células Renais/patologia
Carcinoma de Células Renais/cirurgia
Expressão Gênica
Ácidos Glicéricos/urina
Glicolatos/urina
Seres Humanos
Hiperoxalúria Primária/complicações
Hiperoxalúria Primária/genética
Hiperoxalúria Primária/urina
Rim/metabolismo
Rim/patologia
Rim/cirurgia
Neoplasias Renais/diagnóstico
Neoplasias Renais/patologia
Neoplasias Renais/cirurgia
Masculino
Nefrectomia
Oxo-Ácido-Liases/metabolismo
Urolitíase/complicações
Urolitíase/genética
Urolitíase/urina
[Pt] Tipo de publicação:CASE REPORTS; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Glyceric Acids); 0 (Glycolates); 0WT12SX38S (glycolic acid); 70KH64UX7G (glyceric acid); EC 4.1.3.- (Oxo-Acid-Lyases); EC 4.1.3.16 (4-hydroxy-2-oxoglutarate aldolase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170529
[Lr] Data última revisão:
170529
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161016
[St] Status:MEDLINE
[do] DOI:10.1177/0004563216677101



página 1 de 172 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