Allosteric activation unveils protein-mass modulation of ATP phosphoribosyltransferase product release

Funding: This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) [Grant BB/M010996/1] via an EASTBIO Doctoral Training Partnership studentship to B.J.R.Heavy-isotope substitution into enzymes slows down bond vibrations and may alter transition-state barrier crossing probability if this is coupled to fast protein motions. ATP phosphoribosyltransferase from Acinetobacter baumannii is a multi-protein complex where the regulatory protein HisZ allosterically enhances catalysis by the catalytic protein HisGS. This is accompanied by a shift in rate-limiting step from chemistry to product release. Here we report that isotope-labelling of HisGS has no effect on the nonactivated reaction, which involves negative activation heat capacity, while HisZ-activated HisGS catalytic rate decreases in a strictly mass-dependent fashion across five different HisGS masses, at low temperatures. Surprisingly, the effect is not linked to the chemical step, but to fast motions governing product release in the activated enzyme. Disruption of a specific enzyme-product interaction abolishes the isotope effects. Results highlight how altered protein mass perturbs allosterically modulated thermal motions relevant to the catalytic cycle beyond the chemical step.Peer reviewe

Estudo sobre a relevância da contabilidade nas empresas do setor de atacados do município de Cacoal - RO

Trabalho de Conclusão de Curso apresentado ao Departamento Acadêmico de Ciências Contábeis da Fundação Universidade Federal de Rondônia, campus Professor Francisco Gonçalves Quiles, para obtenção do título de Bacharel em Ciências Contábeis. Orientador: Prof. M.e Rogério SimãoEsta pesquisa teve por objetivo realizar um estudo sobre a relevância da contabilidade para as empresas do setor de atacados de Cacoal – RO. Para alcançar tal objetivo foi feito um levantamento através de entrevista com roteiro estruturado junto aos gestores de empresas do setor de atacados de Cacoal – RO, tendo em vista as informações contidas nas demonstrações contábeis como auxilio gerencial. A pesquisa foi de caráter descritivo e exploratório, com uso de bibliografia em livros e artigos relacionados, a análise dos dados foi de forma qualitativa utilizando como técnica a análise de conteúdo. O instrumento de coleta foi um questionário estruturado contendo perguntas abertas e fechadas, dividido em três partes: primeira, direcionado ao perfil do gerente, em segundo, ao perfil da empresa, e por último, relacionada à relevância e utilidade da contabilidade no auxílio à gestão. Assim verificou-se que a relevância da contabilidade para estes gestores está meramente relacionada ao que a empresa está obrigada a fazer, ou seja, somente o que a legislação determina, nível observado como muito relevante por eles, e pouco ou nada relevante, para auxiliar na tomada de decisão empresarial

A trans10-18:1 enriched fraction from beef fed a barley grain-based diet induces lipogenic gene expression and reduces viability of HepG2 cells.

Beef fat is a natural source of trans (t) fatty acids, and is typically enriched with either t10-18:1 or t11-18:1. Little is known about the bioactivity of individual t-18:1 isomers, and the present study compared the effects of t9-18:1, cis (c)9-18:1 and trans (t)-18:1 fractions isolated from beef fat enriched with either t10-18:1 (HT10) or t11-18:1 (HT11). All 18:1 isomers resulted in reduced human liver (HepG2) cell viability relative to control. Both c9-18:1 and HT11were the least toxic, t9-18:1had dose response increased toxicity, and HT10 had the greatest toxicity (P<0.05). Incorporation of t18:1 isomers was 1.8-2.5 fold greater in triacylglycerol (TG) than phospholipids (PL), whereas Δ9 desaturation products were selectively incorporated into PL. Culturing HepG2 cells with t9-18:1 and HT10 increased (P<0.05) the Δ9 desaturation index (c9-16:1/16:0) compared to other fatty acid treatments. HT10 and t9-18:1 also increased expression of lipogenic genes (FAS, SCD1, HMGCR and SREBP2) compared to control (P<0.05), whereas c9-18:1 and HT11 did not affect the expression of these genes. Our results suggest effects of HT11 and c9-18:1 were similar to BSA control, whereas HT10 and t-9 18:1 (i.e. the predominant trans fatty acid isomer found in partially hydrogenated vegetable oils) were more cytotoxic and led to greater expression of lipogenic genes

Association Studies and Legume Synteny Reveal Haplotypes Determining Seed Size in Vigna unguiculata.

Highly specific seed market classes for cowpea and other grain legumes exist because grain is most commonly cooked and consumed whole. Size, shape, color, and texture are critical features of these market classes and breeders target development of cultivars for market acceptance. Resistance to biotic and abiotic stresses that are absent from elite breeding material are often introgressed through crosses to landraces or wild relatives. When crosses are made between parents with different grain quality characteristics, recovery of progeny with acceptable or enhanced grain quality is problematic. Thus genetic markers for grain quality traits can help in pyramiding genes needed for specific market classes. Allelic variation dictating the inheritance of seed size can be tagged and used to assist the selection of large seeded lines. In this work we applied 1,536-plex SNP genotyping and knowledge of legume synteny to characterize regions of the cowpea genome associated with seed size. These marker-trait associations will enable breeders to use marker-based selection approaches to increase the frequency of progeny with large seed. For 804 individuals derived from eight bi-parental populations, QTL analysis was used to identify markers linked to 10 trait determinants. In addition, the population structure of 171 samples from the USDA core collection was identified and incorporated into a genome-wide association study which supported more than half of the trait-associated regions important in the bi-parental populations. Seven of the total 10 QTLs were supported based on synteny to seed size associated regions identified in the related legume soybean. In addition to delivering markers linked to major trait determinants in the context of modern breeding, we provide an analysis of the diversity of the USDA core collection of cowpea to identify genepools, migrants, admixture, and duplicates

Crystal structure, steady-state and pre-steady-state kinetics of Acinetobacter baumannii ATP phosphoribosyltransferase

Funding: This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) (grant BB/M010996/1) via an EASTBIO Doctoral Training Partnership studentship to B.J.R.The first step of histidine biosynthesis in Acinetobacter baumannii, the condensation of ATP and 5-phospho-α-d-ribosyl-1-pyrophosphate to produce N1-(5-phospho-β-d-ribosyl)-ATP (PRATP) and pyrophosphate, is catalyzed by the hetero-octameric enzyme ATP phosphoribosyltransferase, a promising target for antibiotic design. The catalytic subunit, HisGS, is allosterically activated upon binding of the regulatory subunit, HisZ, to form the hetero-octameric holoenzyme (ATPPRT), leading to a large increase in kcat. Here, we present the crystal structure of ATPPRT, along with kinetic investigations of the rate-limiting steps governing catalysis in the nonactivated (HisGS) and activated (ATPPRT) forms of the enzyme. A pH-rate profile showed that maximum catalysis is achieved above pH 8.0. Surprisingly, at 25 °C, kcat is higher when ADP replaces ATP as substrate for ATPPRT but not for HisGS. The HisGS-catalyzed reaction is limited by the chemical step, as suggested by the enhancement of kcat when Mg2+ was replaced by Mn2+, and by the lack of a pre-steady-state burst of product formation. Conversely, the ATPPRT-catalyzed reaction rate is determined by PRATP diffusion from the active site, as gleaned from a substantial solvent viscosity effect. A burst of product formation could be inferred from pre-steady-state kinetics, but the first turnover was too fast to be directly observed. Lowering the temperature to 5 °C allowed observation of the PRATP formation burst by ATPPRT. At this temperature, the single-turnover rate constant was significantly higher than kcat, providing additional evidence for a step after chemistry limiting catalysis by ATPPRT. This demonstrates allosteric activation by HisZ accelerates the chemical step.Publisher PDFPeer reviewe

Vanadium doping effect on multifunctionality of SnO2 nanoparticles

In the present study, tin oxide (SnO2) nanoparticles were synthesized by a precursor polymeric method. The obtained nanoparticles were doped with vanadium. The samples were characterized by powder XRD, TEM, optical UV and EPR studies. XRD and TEM showed the rutile crystal structure and its revealed that the lattice cell parameters and particles size were decreased with dopant level. Optical and EPR data confirmed that the doped V enters into SnO2 and distorted the host material symmetry. The films sensing characteristics have been studied from the aspect of doping level of sensing material and microstructure. It is found that V doping on SnO2 enhance sensor sensitivity towards CO gas. The results demonstrated that V doping can improving numerous applications which the SnO2 response is maximized.Fil: Alvarez Roca, Roman. Universidade Federal do São Carlos; BrasilFil: Desimone, Paula Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: da Silva, Mitchell. Universidade Federal do São Carlos; BrasilFil: Ponce, Miguel Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Longo, Elson. Universidade Federal do São Carlos; Brasi

“Retornem para os seus países” parlamentares de cor: Trump, racismo e a repercussão na mídia negra dos EUA

Este artigo analisa, sob a perspectiva da interseccionalidade, a repercussão das mensagens racistas  do presidente  Donald Trump  na mídia negra estadunidense, no episódio envolvendo as quatro parlamentares de cor estreantes no Congresso Nacional pelo Partido Democrata. Nos posts publicados no Twitter, observa-se como gênero, raça, geração, nacionalidade e posicionamento político foram acionados por Trump para  discriminar  e  “mandar”   as parlamentares voltarem aos seus respectivos países de origem. Baseado na análise de conteúdo de cinco mídias negras, verifica-se que a cobertura  destacou os tweets e a trajetória racista de Trump. Pouca intersecção foi realizada para mostrar os cruzamentos entre as categorias utilizadas por ele para agredir as parlamentares. 

Adaptive Platforms and Flexible Deposition System for Big Area Additive Manufacturing (BAAM)

The interest around the additive manufacturing is increasing, with more and more solutions at both the industrial and desktop levels. As this is still a relatively recent issue for several industrial areas, there is a clear opportunity to explore in order to optimize the systems in the face of the needs of these same industries, and with increasing times, there are increasing factors to take into ac- count in initial phases of new product development. Presently, there is also a growing ecological awareness, with the concern of implementing a logic of waste reduction and implementation of the circular economy in new products with a view to the valuation of new alternative materials. With the development of solutions aimed at the optimization and feasibility of large additive manufacturing systems, the introduction of new alternative materials will be a reality, presenting in this article a solution and methodology for future tests for new materials. Thus, herein is studied a way of responding to both problems, new ecological materials and BAAM system optimization, presented through a hybrid and flexible solution based on the Pin Bed Forming principle applied to Big Area Additive Manufacturing systems.info:eu-repo/semantics/publishedVersio

Evaluation of Afterschool Activity Programs’ (ASAP) Effect on Children’s Physical Activity, Physical Health, and Fundamental Movement Skills

Publisher Copyright: © The Author(s) 2021.Background: Physical literacy-focused afterschool activity programs (ASAPs) can be an effective strategy to improve children’s health-related parameters. We sought to compare physical activity, body composition, aerobic capacity, and fundamental movement skills between physical literacy-focused ASAP and a standard recreational ASAP. Method: A pre–post (6 months) comparison study was conducted in 5- to 12-year-old children in a physical literacy-focused ASAP (physical literacy group, n = 14) and children attending a standard recreational ASAP (comparison group, n = 15). Physical activity guideline adherence was assessed using accelerometry, body composition was analyzed using bioelectrical impedance, aerobic capacity was estimated using the Progressive Aerobic Cardiovascular Endurance Run test, and fundamental movement skills were evaluated using the Test of Gross Motor Development–2. Results: There were no significant differences between groups at baseline. After 6 months, the physical literacy group exhibited a significant improvement in their total raw score for the Test of Gross Motor Development–2 (p =.016), which was likely due to improvements in object control skills (p =.024). The comparison group significantly increased body mass index (p =.001) and body fat (p =.009) over time. No significant between-group differences were found; however, there was a trend for improved aerobic capacity in the physical literacy group (d = 0.58). Conclusions: Engagement in the physical literacy-focused ASAP contributed to an attenuated increase in adiposity and an improvement in object control skills.Peer reviewe

Geo-environmental mapping using physiographic analysis: constraints on the evaluation of land instability and groundwater pollution hazards in the Metropolitan District of Campinas, Brazil

Geo-environmental terrain assessments and territorial zoning are useful tools for the formulation and implementation of environmental management instruments (including policy-making, planning, and enforcement of statutory regulations). They usually involve a set of procedures and techniques for delimitation, characterisation and classification of terrain units. However, terrain assessments and zoning exercises are often costly and time-consuming, particularly when encompassing large areas, which in many cases prevent local agencies in developing countries from properly benefiting from such assessments. In the present paper, a low-cost technique based on the analysis of texture of satellite imagery was used for delimitation of terrain units. The delimited units were further analysed in two test areas situated in Southeast Brazil to provide estimates of land instability and the vulnerability of groundwater to pollution hazards. The implementation incorporated procedures for inferring the influences and potential implications of tectonic fractures and other discontinuities on ground behaviour and local groundwater flow. Terrain attributes such as degree of fracturing, bedrock lithology and weathered materials were explored as indicators of ground properties. The paper also discusses constraints on- and limitations of- the approaches taken