RESUMO
Catechol 1,2 dioxygenases (C12DOs) have been studied for its ability to cleavage the benzene ring of catechol, the main intermediate in the degradation of aromatic compounds derived from aerobic degradation of hydrocarbons. Here we report the genome sequence of the marine bacterium Pseudomonas stutzeri GOM2, isolated from the southwestern Gulf of Mexico, and the biochemical characterization of its C12DO (PsC12DO). The catA gene, encoding PsC12DO of 312 amino acid residues, was cloned and expressed in Escherichia coli. Many C12DOs have been described as dimeric enzymes including those present in Pseudomonas species. The purified PsC12DO enzyme was found as an active trimer, with a molecular mass of 107 kDa. Increasing NaCl concentration in the enzyme reaction gradually reduced activity; in high salt concentrations (0.7 M NaCl) quaternary structural analysis determined that the enzyme changes to a dimeric arrangement and causes a 51% decrease in specific activity on catechol substrate. In comparison with other C12DOs, our enzyme showed a broad range of action for PsC12DO in solutions with pH values ranging from neutral to alkaline (70%). The enzyme is still active after incubation at 50°C for 30 min and in low temperatures to long term storage after 6 weeks at 4°C (61%). EDTA or Ca2+ inhibitors cause no drastic changes on residual activity; nevertheless, the activity of the enzyme was affected by metal ions Fe3+, Zn2+ and was completely inhibited by Hg2+. Under optimal conditions the k cat and K m values were 16.13 s-1 and 13.2 µM, respectively. To our knowledge, this is the first report describing the characterization of a marine C12DOs from P. stutzeri isolated from the Gulf of Mexico that is active in a trimeric state. We consider that our enzyme has important features to be used in environments in presence of EDTA, metals and salinity conditions.
RESUMO
Recombinant protein expression is one of the key issues in protein engineering and biotechnology. Among the different models for assessing protein production and structure-function studies, green fluorescent protein (GFP) is one of the preferred models because of its importance as a reporter in cellular and molecular studies. In this research we analyze the effect of codon deletions near the amino terminus of different GFP proteins on fluorescence. Our study includes Gly4 deletions in the enhanced GFP (EGFP), the red-shifted GFP and the red-shifted EGFP. The Gly4 deletion mutants and their corresponding wild-type counterparts were transcribed under the control of the T7 or Trc promoters and their expression patterns were analyzed. Different fluorescent outcomes were observed depending on the type of fluorescent gene versions. In silico analysis of the RNA secondary structures near the ribosome binding site revealed a direct relationship between their minimum free energy and GFP production. Integrative analysis of these results, including SDS-PAGE analysis, led us to conclude that the fluorescence improvement of cells expressing different versions of GFPs with Gly4 deleted is due to an enhancement of the accessibility of the ribosome binding site by reducing the stability of the RNA secondary structures at their mRNA leader regions.
Assuntos
Códon , Expressão Gênica , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Deleção de Sequência , Biologia Computacional , Fluorometria , Conformação de Ácido Nucleico , RNA Mensageiro/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Ribossomos/metabolismoRESUMO
A cigar is a smoked-tobacco product made of cured and fermented leaves rolled into a cylindrical shape. Many types of cigars are available on the market today—they vary in size, shape, flavor, and type of filter and wrapper. These traits often determine the name given to each product. When the United States instituted a tax increase on cigarettes, smokeless tobacco products, and cigars in 2009 through the Children’s Health insurance Program Reauthorization Act (1), consumption of some smoked-tobacco products rose. In fact, the higher cigarette/cigar tax positioned small cigars among the country’s most popular tobacco products (2). This was partly a result of manufacturers making their small cigars slightly heavier to qualify for a preferential tax rate, avoiding the higher taxes leveed by the 2009 law. Sales of smaller cigars such as “little cigars” and cigarrillos have increased tremendously since that time, by 238% and 148%, respectively. The growing popularity of these non-cigarette smoked-tobacco products has been multiplied by their availability for purchase as single units and in different flavors (e.g., apple, strawberry, grape, chocolate, vanilla), which makes them more appealing to youth and young adults...
Assuntos
Fumar , NicotianaRESUMO
Se hace una descripción anatómica y fisiológica de la columna vertebral y de la etiología y fisiopatología de la hiperlordosis. También se hacen consideraciones sobre el uso de zapatos inadecuados y sus consecuencias en los pies.
Assuntos
Humanos , Cifose/complicações , Cifose/diagnóstico , Cifose/prevenção & controle , Coluna Vertebral/anormalidades , Espondilolistese/diagnósticoRESUMO
En el Hospital de Traumatología y Ortopedia "Lomas Verdes" del Instituto Mexicano del Seguro Social, en el Módulo de extremidad Torácica, se trataron quirúrgicamente 42 pacientes de síndrome de hombro doloroso, por tenonitis del bicipital. Seis de ellos presentaron capsulitis adhesiva. El periodo se estudio compresndió de marzo de 1987 a marzo de 1991, el diagnóstico se realizó con base en estudios clínicos-radiográficos, los cuales se complementaron con ultrasonografía en 10 pacientes. En todos fracasó el tratamiento conservador y se excluyó del estudio a aquellos en quienes existía patología metabólica de fondo. Se utilizaron tres procedimientos de acuerdo con los hallazgos transoperatorios; revisión, tenodesis en la corredera bicipital y transposición tendinosa de la porción larga del bíceps a la apófisis coracoides. En todos los casos se realizó liberación quirúrgica subacromial y en seis se agregó capsulotomía ántero-inferior. La evaluación postoperatoria final se realizó a los cinco años como máximo y seis meses como mínimo; se obtuvieron 13 (30 por ciento) de casos excelentes; 24 (57 por ciento) de buenos resultados; cuatro (10 por ciento) regulares y uno (2 por ciento) malo.
Assuntos
Humanos , Masculino , Feminino , Adulto , Procedimentos Cirúrgicos Operatórios , Procedimentos Cirúrgicos Operatórios/reabilitação , Tendões/anatomia & histologia , Tendões/cirurgia , Articulação Acromioclavicular/cirurgia , Articulação Acromioclavicular/fisiopatologia , Úmero/cirurgia , Úmero/fisiopatologia , Músculos/cirurgia , Músculos/fisiopatologiaRESUMO
La disquectomía lumbar percutánea automatizada (DLPA) es un nuevo procedimiento para el tratamiento de un disco lumbar herniado, usando anestesia local y la ayuda de un intensificador de imágenes como guía. Una cánula especialmente diseñada (nucleotomo) con un diámetro de 2 mm es colocada dentro del disco y éste es estraído por corte y aspiración en lugar de la cirugía convencional bajo anestesia general. A partir del mes de junio de 1989, en el Hospital de Traumatología y Ortopedia de Lomas Verdes del IMSS se ha iniciado su utilización en los casos considerados adecuados para ello. Comunicamos la experiencia obtenida con los primeros 20 casos de su aplicación que fueron 12 para L4 y ocho para L5. El seguimiento fue de tres a ocho meses con promedio de seis. El resultado fue satisfactorio en 15 pacientes y en cinco no satisfactorio. En dos de ellos se diagnosticó hernia extrusa y en otro un fragmento de disco libre subligamentario mediante discografía-TAC. Los tres sometieron a hemilaminectomía, comprobado el diagnóstico. Los dos restantes rehusaron todo estudio y tratamiento complementario.