A survey of genes encoding H2O2-producing GMC oxidoreductases in 10 Polyporales genomes

The genomes of three representative Polyporales (Bjerkandera adusta, Phlebia brevispora and a member of the Ganoderma lucidum complex) recently were sequenced to expand our knowledge on the diversity and distribution of genes involved in degradation of plant polymers in this Basidiomycota order, which includes most wood-rotting fungi. Oxidases, including members of the glucose-methanol-choline (GMC) oxidoreductase superfamily, play a central role in the above degradative process because they generate extracellular H2O2 acting as the ultimate oxidizer in both white-rot and brown-rot decay. The survey was completed by analyzing the GMC genes in the available genomes of seven more species to cover the four Polyporales clades. First, an in silico search for sequences encoding members of the aryl-alcohol oxidase, glucose oxidase, methanol oxidase, pyranose oxidase, cellobiose dehydrogenase and pyranose dehydrogenase families was performed. The curated sequences were subjected to an analysis of their evolutionary relationships, followed by estimation of gene duplication/ reduction history during fungal evolution. Second, the molecular structures of the near one hundred GMC oxidoreductases identified were modeled to gain insight into their structural variation and expected catalytic properties. In contrast to ligninolytic peroxidases, whose genes are present in all white-rot Polyporales genomes and absent from those of brown-rot species, the H2O2-generating oxidases are widely distributed in both fungal types. This indicates that the GMC oxidases provide H2O2 for both ligninolytic peroxidase activity (in white-rot decay) and Fenton attack on cellulose (in brown-rot decay), after the transition between both decay patterns in Polyporales occurred

Estudo comparativo entre fusão lombar posterior com parafuso pedicular e fusão intersomática lombar posterior associada com parafuso pedicular em espondilolistese no adulto

The purpose of this study was to compare patients with lumbar spondylolisthesis submitted to two different surgical approaches, and evaluate the results and outcomes in both groups. In a two-year period, 60 adult patients with lumbar spondylolisthesis, both isthmic and degenerative, were submitted to surgery at the Biocor Institute, Brazil. All patients were operated on by the same surgeon (FLRD) in a single institution, and the results were analyzed prospectively. Group I comprised the first 30 consecutive patients that were submitted to a posterior lumbar spinal fusion with pedicle screws (PLF). Group II comprised the last 30 consecutive patients submitted to a posterior lumbar interbody fusion procedure (PLIF) with pedicle screws. All patients underwent foraminotomy for nerve root decompression. Clinical evaluation was carried out using the Prolo Economic and Functional Scale and the Rolland-Morris and the Oswestry questionnaire. Mean age was 52.4 for Group I (PLF), and 47.6 for Group II (PLIF). The mean follow-up was 3.2 years. Both surgical procedures were effective. The PLIF with pedicle screws group presented better clinical outcomes. Group I presented more complications when compared with Group II. Group II presented better results as indicated in the Prolo Economic and Functional Scale.O objetivo foi comparar dois grupos de pacientes portadores de espondilolistese lombar que foram submetidos a dois procedimentos cirúrgicos distintos, avaliando os resultados clínicos levando em consideração a qualidade de vida. Durante o período de 1998 a 2001 sessenta pacientes portadores de espondilolistese da coluna lombar ístmica e degenerativa foram submetidos a tratamento cirúrgico no Hospital Biocor em Belo Horizonte, por um mesmo cirurgião foram analisados prospectivamente. Os primeiros trinta pacientes foram submetidos a fusão posterior com parafusos pediculares e os trinta seguintes a fusão posterior com parafusos pediculares associada a fusão intersomática posterior. Os pacientes foram submetidos a liberação radicular com laminectomia e foraminotomia. A avaliação clínica foi feita utilizando as escalas de Prolo Econômico e Funcional, o questionário de Rolland-Morris e de Oswestry. Os resultados clínicos apresentaram que os dois procedimentos realizados foram eficazes. Houve maior número de complicações relacionadas com a biomecânica no grupo que foi submetido somente à fusão posterior e o grupo submetido à fusão posterior associada a fusão intersomática apresentou melhores resultados com retorno as atividades diárias e melhora da qualidade de vida.Hospital BiocorUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Federal de São Paulo (UNIFESP)Hospital Madre TerezaUNIFESP, EPMUNIFESPSciEL

Impact of a 2-year intervention program on cardiometabolic profile according to the number of goals achieved

We investigated the impact of lifestyle goal achievement on cardiovascular risk factors after a 2-year behavioral intervention program applied to 394 adults (113 with diabetes, mean age 60.2 ± 11.4 years, 56% women) and targeting four goals: &#8805;5% weight loss; &#8805;150 min/week physical activities; <10% saturated fat intake/day; &#8805;400 g fruit and vegetable intake/day. Baseline characteristics and changes in variables after intervention among the four categories of number of goals achieved (none, 1, 2, and &#8805;3) were compared by independent ANOVA or the Kruskal-Wallis test. Individuals without diabetes achieving a higher number of goals were more likely to be older (3 or 4 goals: 61.8 ± 12.6 years vs none: 53.3 ± 10.3 years, P < 0.05) and to have a lower mean BMI (3 or 4 goals: 21.7 ± 2.6 kg/m² vs none: 29.0 ± 4.8 kg/m², P < 0.05), diastolic blood pressure (3 or 4 goals: 77.3 ± 2.1 mmHg vs none: 85.4 ± 9.6 mmHg, P < 0.05), triglyceride (3 or 4 goals: 116.1 ± 95.1 mg/dL vs none: 144.8 ± 65.5 mg/dL, P < 0.05) and insulin levels (3 or 4 goals: 3.6 ± 2.4 &#956;U/L vs none: 5.7 ± 4.0 &#956;U/L, P < 0.05) than those achieving fewer goals. The absolute changes in cardiovascular risk factors tended to be more pronounced with increasing number of goals achieved in individuals without diabetes. The intervention had a beneficial impact on the cardiometabolic profile of individuals with normal or altered glucose metabolism. The number of goals achieved in this lifestyle intervention was associated with the magnitude of improvement of cardiovascular risk factors in individuals without diabetes. Participants with a better cardiometabolic profile seemed to be more likely to have a healthy lifestyle

Focused directed evolution of aryl-alcohol oxidase in Saccharomyces cerevisiae by using chimeric signal peptides

Aryl-alcohol oxidase (AAO) is an extracellular flavoprotein that supplies ligninolytic peroxidases with H2O2 during natural wood decay. With a broad substrate specificity and highly stereoselective reaction mechanism, AAO is an attractive candidate for studies into organic synthesis and synthetic biology, and yet the lack of suitable heterologous expression systems has precluded its engineering by directed evolution. In this study, the native signal sequence of AAO from Pleurotus eryngii was replaced by those of the mating a-factor and the K1 killer toxin, as well as different chimeras of both prepro-leaders in order to drive secretion in Saccharomyces cerevisiae. The secretion of these AAO constructs increased in the following order: preproa-AAO> preaproK-AAO>preKproa-AAO>preproK-AAO. The chimeric preaproK-AAO was subjected to focused-directed evolution with the aid of a dual screening assay based on the Fenton reaction. Random mutagenesis and DNA recombination was concentrated on two protein segments (Meta1]-Val109 and Phe392-Gln566), and an array of improved variants was identified, among which the FX7 mutant (harboring the H91N mutation) showed a dramatic 96-fold improvement in total activity with secretion levels of 2 mg/liter. Analysis of the N-terminal sequence of the FX7 variant confirmed the correct processing of the preaproK hybrid peptide by the KEX2 protease. FX7 showed higher stability in terms of pH and temperature, whereas the pH activity profiles and the kinetic parameters were maintained. The Asn91 lies in the flavin attachment loop motif, and it is a highly conserved residue in all members of the GMC superfamily, except for P. eryngii and P. pulmonarius AAO. The in vitro involution of the enzyme by restoring the consensus ancestor Asn91 promoted AAO expression and stability

Nonlinear Finite Element Analysis of Rubber Composite Shells

A finite-element solution for rubber composite shells is presented. Sandwich laminates with a rubber core have also been studied. Incompressibility of a rubber matrix and complexity of composite shells bring forth the need for a sound numerical model to describe the behavior of such engineering materials. The developed model was applied to a degenerate shell element within the limits of the first- and thirdorder shear deformation theories. The model allows to predict with a sufficient accuracy the nonlinear behavior of sandwich shells with composite skins and rubber cores and composite shells with a rubber matrix.Представлено конечноэлементное решение для композитных оболочек с каучуковой матрицей. Рассматриваются также многослойные конструкции с каучуковой основой. Для учета несжимаемости каучуковой матрицы и неоднородности структуры многослойных оболочек необходимо разработать на основе численных методов хорошо обоснованную модель, описывающую поведение указанных строительных материалов. Предложенная модель применялась авторами к вырожденному элементу оболочки в рамках деформационных теорий сдвига первого и третьего порядка. Модель позволяет достаточно точно прогнозировать нелинейное поведение многослойных оболочек с тонкими прослойками из композитного материала и слоями каучука, а также композитных оболочек с каучуковой матрицей.Наведено скінченноелементннй розв’язок для композитних оболонок із каучуковою матрицею. Розглядаються також багатошарові конструкції з каучуковою основою. Для урахування нестисливості каучукової матриці і неоднорідності структури багатошарових оболонок необхідно розробити на основі числових методів добре обгрунтовану модель, що дозволить описати поведінку указаних будівельних матеріалів. Запропонована модель застосовувалась авторами до виродженого елемента оболонки в рамках деформаційних теорій зсуву першого і третього порядку. Модель дозволяє достатньо точно прогнозувати нелінійну поведінку багатошарових оболонок із тонкими прошарками з композитного матеріалу і шарами каучука, а також композитних оболонок із каучуковою матрицею

Survival-extinction phase transition in a bit-string population with mutation

A bit-string model for the evolution of a population of haploid organisms, subject to competition, reproduction with mutation and selection is studied, using mean field theory and Monte Carlo simulations. We show that, depending on environmental flexibility and genetic variability, the model exhibits a phase transtion between extinction and survival. The mean-field theory describes the infinite-size limit, while simulations are used to study quasi-stationary properties.Comment: 11 pages, 5 figure

Self-sustained enzymatic cascade for the production of 2, 5-furandicarboxylic acid from 5-methoxymethylfurfural

Background: 2, 5-Furandicarboxylic acid is a renewable building block for the production of polyfurandicarboxylates, which are biodegradable polyesters expected to substitute their classical counterparts derived from fossil resources. It may be produced from bio-based 5-hydroxymethylfurfural or 5-methoxymethylfurfural, both obtained by the acidic dehydration of biomass-derived fructose. 5-Methoxymethylfurfural, which is produced in the presence of methanol, generates less by-products and exhibits better storage stability than 5-hydroxymethylfurfural being, therefore, the industrial substrate of choice. Results: In this work, an enzymatic cascade involving three fungal oxidoreductases has been developed for the production of 2, 5-furandicarboxylic acid from 5-methoxymethylfurfural. Aryl-alcohol oxidase and unspecific peroxygenase act on 5-methoxymethylfurfural and its partially oxidized derivatives yielding 2, 5-furandicarboxylic acid, as well as methanol as a by-product. Methanol oxidase takes advantage of the methanol released for in situ producing H2O2 that, along with that produced by aryl-alcohol oxidase, fuels the peroxygenase reactions. In this way, the enzymatic cascade proceeds independently, with the only input of atmospheric O2, to attain a 70% conversion of initial 5-methoxymethylfurfural. The addition of some exogenous methanol to the reaction further improves the yield to attain an almost complete conversion of 5-methoxymethylfurfural into 2, 5-furandicarboxylic acid. Conclusions: The synergistic action of aryl-alcohol oxidase and unspecific peroxygenase in the presence of 5-methoxymethylfurfural and O2 is sufficient for the production of 2, 5-furandicarboxylic acid. The addition of methanol oxidase to the enzymatic cascade increases the 2, 5-furandicarboxylic acid yields by oxidizing a reaction by-product to fuel the peroxygenase reactions

Theoretical description of deformed proton emitters: nonadiabatic coupled-channel method

The newly developed nonadiabatic method based on the coupled-channel Schroedinger equation with Gamow states is used to study the phenomenon of proton radioactivity. The new method, adopting the weak coupling regime of the particle-plus-rotor model, allows for the inclusion of excitations in the daughter nucleus. This can lead to rather different predictions for lifetimes and branching ratios as compared to the standard adiabatic approximation corresponding to the strong coupling scheme. Calculations are performed for several experimentally seen, non-spherical nuclei beyond the proton dripline. By comparing theory and experiment, we are able to characterize the angular momentum content of the observed narrow resonance.Comment: 12 pages including 10 figure

Sorogrupos e genes de virulência em Escherichia coli isoladas de psitacídeos

Escherichia coli isolates from 24 sick psittacine birds were serogrouped and investigated for the presence of genes encoding the following virulence factors: attaching and effacing (eae), enteropathogenic E. coli EAF plasmid (EAF), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afa), capsule K1 (neu), curli (crl, csgA), temperature-sensitive hemagglutinin (tsh), enteroaggregative heat-stable enterotoxin-1 (astA), heat-stable enterotoxin -1 heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga-like toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf1), haemolysin (hly), aerobactin production (iuc) and serum resistance (iss). The results showed that the isolates belonged to 12 serogroups: O7; O15; O21; O23; O54; O64; O76; O84; O88; O128; O152 and O166. The virulence genes found were: crl in all isolates, pap in 10 isolates, iss in seven isolates, csgA in five isolates, iuc and tsh in three isolates and eae in two isolates. The combination of virulence genes revealed 11 different genotypic patterns. All strains were negative for genes encoding for EAF, EAEC, K1, sfa, afa, hly, cnf, LT, STa, STb, stx1 and stx2. Our findings showed that some E. coli isolated from psittacine birds present the same virulence factors as avian pathogenic E. coli (APEC), uropathogenic E. coli (UPEC) and Enteropathogenic E. coli (EPEC) pathotypes.Amostras de Escherichia coli isoladas de 24 psitacídeos doentes foram sorogrupadas e investigadas para a presença de genes que codificam os seguintes fatores de virulência: attaching e effacing (eae), plasmídeo EAF (EAF), pili associado à pielonefrite (pap), fímbria S (sfa), adesina afimbrial (afa), cápsula K1 (neu), curli (crl, csgA), hemaglutinina termosensível (tsh), enterotoxina termo-estável 1 de E. coli enteroagregativa (astA), toxina termolábil (LT) e toxina termoestável (STa e STb), Shiga-like toxinas (stx1 e stx2), fator citotóxico necrotizante 1 (cnf1), hemolisina (hly), produção de aerobactina (iuc) e resistência sérica (iss). Os resultados mostraram que os isolados pertenciam a 12 sorogrupos: O7; O15; O21; O23; O54; O64; O76; O84; O88; O128; O152 e O166. Os genes de virulência encontrados foram: crl em todos os isolados, pap em 10 isolados, iss em sete isolados, csgA em cinco isolados, iuc e tsh em três isolados e eae em dois isolados. A combinação dos genes de virulência revelou 11 perfis genotípicos distintos. Todas as amostras foram negativas para os genes que codificam EAF, EAEC, K1, sfa, afa, hly, cnf, LT, STa, STb, stx1 e stx2. Estes resultados demonstraram que algumas amostras de E. coli isoladas de psitacídeos apresentam os mesmos fatores de virulência presentes nos patotipos de E. coli patogênicas para aves (APEC), uropatogênicas (UPEC) e E. coli enteropatogênicas (EPEC).916921Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Shell model in the complex energy plane and two-particle resonances

An implementation of the shell-model to the complex energy plane is presented. The representation used in the method consists of bound single-particle states, Gamow resonances and scattering waves on the complex energy plane. Two-particle resonances are evaluated and their structure in terms of the single-particle degreees of freedom are analysed. It is found that two-particle resonances are mainly built upon bound states and Gamow resonances, but the contribution of the scattering states is also important.Comment: 20 pages, 9 figures, submitted to Phys.Rev.