Involvement of a Natural Fusion of a Cytochrome P450 and a Hydrolase in Mycophenolic Acid Biosynthesis

Mycophenolic acid (MPA) is a fungal secondary metabolite and the active component in several immunosuppressive pharmaceuticals. The gene cluster coding for the MPA biosynthetic pathway has recently been discovered in Penicillium brevicompactum, demonstrating that the first step is catalyzed by MpaC, a polyketide synthase producing 5-methylorsellinic acid (5-MOA). However, the biochemical role of the enzymes encoded by the remaining genes in the MPA gene cluster is still unknown. Based on bioinformatic analysis of the MPA gene cluster, we hypothesized that the step following 5-MOA production in the pathway is carried out by a natural fusion enzyme MpaDE, consisting of a cytochrome P450 (MpaD) in the N-terminal region and a hydrolase (MpaE) in the C-terminal region. We verified that the fusion gene is indeed expressed in P. brevicompactum by obtaining full-length sequence of the mpaDE cDNA prepared from the extracted RNA. Heterologous coexpression of mpaC and the fusion gene mpaDE in the MPA-nonproducer Aspergillus nidulans resulted in the production of 5,7-dihydroxy-4-methylphthalide (DHMP), the second intermediate in MPA biosynthesis. Analysis of the strain coexpressing mpaC and the mpaD part of mpaDE shows that the P450 catalyzes hydroxylation of 5-MOA to 4,6-dihydroxy-2-(hydroxymethyl)-3-methylbenzoic acid (DHMB). DHMB is then converted to DHMP, and our results suggest that the hydrolase domain aids this second step by acting as a lactone synthase that catalyzes the ring closure. Overall, the chimeric enzyme MpaDE provides insight into the genetic organization of the MPA biosynthesis pathway

Electrodeposition of CuGaSe2 and CuGaS2 thin films for photovoltaic applications

The final publication is available at Springer via http://dx.doi.org/10.1007/s10008-016-3237-0.Abstract CuGaSe2 and CuGaS2 polycrystalline thin film absorbers were prepared by one-step electrodeposition from an aqueous electrolyte containing CuCl2, GaCl3 and H2SeO3. The pH of the solution was adjusted to 2.3 by adding HCl and KOH. Annealing improved crystallinity of CuGaSe2 and further annealing in sulphur atmosphere was required to obtain CuGaS2 layers. The morphology, topography, chemical composition and crystal structure of the deposited thin films were analysed by scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy and X-ray diffraction, respectively. X-Ray diffraction showed that the asdeposited CuGaSe2 film exhibited poor crystallinity, but which improved dramatically when the layers were annealed in forming gas atmosphere for 40 min. Subsequent sulphurization of CuGaSe2 films was performed at 400 °C for 10 min in presence of molecular sulphur and under forming gas atmosphere. The effect of sulphurization was the conversion of CuGaSe2 into CuGaS2. The formation of CuGaS2 thin films was evidenced by the shift observed in the X-ray diffraction pattern and by the blue shift of the optical bandgap. The bandgap of CuGaSe2 was found to be 1.66 eV, while for CuGaS2 it raised up to 2.2 eV. A broad intermediate absorption band associated to Cr and centred at 1.63 eV was observed in Cr-doped CuGaS2 films.This work was supported by Ministerio de Economia y Competitividad (ENE2013-46624-C4-4-R) and Generalitat Valenciana (Prometeus 2014/044). One of the authors (S. Ullah) acknowledges the European Union (IDEAS-Call-3, Innovation and Design for Euro-Asian scholars) for its financial support.Ullah, S.; Mollar García, MA.; Marí, B. (2016). Electrodeposition of CuGaSe2 and CuGaS2 thin films for photovoltaic applications. Journal of Solid State Electrochemistry. 20(8):2251-2257. https://doi.org/10.1007/s10008-016-3237-0S22512257208Calixto ME, Sebastian PJ, Bhattacharya RN, Noufi (1999) Sol Energ Mat Sol C 59:75–84Mandati S, Sarada BV, Dey SR, Joshi SV (2015) J Power Sources 273:149–157Jacobsson TJ, Fjällström V, Edoff M, Edvinsson T (2015) Sol Energ Mat Sol C 134:185–193Carrete A, Placidi M, Shavel A, Pérez Rodríguez A, Cabot A (2015) Phys Stat Sol (a) 212:67–71Saji VS, Ik-Ho C, Lee CW (2011) Sol Energy 86:2666–2678Park MG, Ahn SJ, Yun JH, Gwak J, Cho A, Ahn SK, Shin K, Nam D, Cheong H, Yoon K (2012) J Alloy Compd 513:68–74Saji VS, Lee SM, Lee CW (2011) J Korean Electrochem Soc 14:61–70Donglin X, Jangzhuang L, Man X, Xiujian Z (2008) J Non-Cryst Solids 354:1447–1450Araujo J, Ortíz R, López-Rivera A, Ortega JM, Montilla M, Alarcón D (2007) J Solid State Electroch 11(Issue 3):407–412Palacios P, Sanchez K, Conesa JC, Fernandez JJ, Wahnon P (2007) Phys Stat Sol A 203:1395–1401Palacios P, Sanchez K, Conesa JC, Wahnon P (2006) Thin Solid Films 515:6280–6284Lee H, Lee J-H, Hwang Y-H, Kim Y (2014) Curr Appl Phys 14:18–22Kim D, Kwon Y, Lee D, Yoon S, Lee S, Yoo B (2015) J Electrochem Soc 162:D36–D41Hou WW, Bob B, Li S, Yang Y (2009) Thin Solid Films 517:6853–6856Lee J, Lee W, Shrestha NK, Lee DY, Lim I, Kang SH, Nah YC, Lee SH, Yi W, Han SH (2014) Mater Chem Phys 144:49–54Yang JY, Lee D, Huh K, Jung SJ, Lee JW, Lee HC, Baek DH, Kim BJ, Kim D, Nam J, Kim GY, Jo W (2015) RSC Adv 5:40719–407257Sall T, Nafidi A, Marí B, Mollar M, Hartiti B, Fahoume M (2014) J Semicond 35:0630021–0630025Lee JH, Song WC, Yi JS, Joonyang K, Han WD, Hawang J (2003) Thin Solid Films 431-432:349–353Prabukanthan P, Dhanasekaran R (2007) Cryst Growth Des 7:618–623Guillemoles JF, Cowache P, Lusson A, Fezzaa K, Boisivon F, Vedel J, Lincot D (1996) J Appl Phys 79:7293–7302Aguilera I, Palacios P, Wahon P (2010) Sol Energ Mat Sol C 94:1903–1906Palacios P, Aguilera I, Wahnón P, Conesa JC (2008) J Phys Chem C 112:9525–952

Optimal functional outcome measures for assessing treatment for Dupuytren's disease: A systematic review and recommendations for future practice

This article is available through the Brunel Open Access Publishing Fund. Copyright © 2013 Ball et al.; licensee BioMed Central Ltd.Background: Dupuytren's disease of the hand is a common condition affecting the palmar fascia, resulting in progressive flexion deformities of the digits and hence limitation of hand function. The optimal treatment remains unclear as outcomes studies have used a variety of measures for assessment. Methods: A literature search was performed for all publications describing surgical treatment, percutaneous needle aponeurotomy or collagenase injection for primary or recurrent Dupuytren’s disease where outcomes had been monitored using functional measures. Results: Ninety-one studies met the inclusion criteria. Twenty-two studies reported outcomes using patient reported outcome measures (PROMs) ranging from validated questionnaires to self-reported measures for return to work and self-rated disability. The Disability of Arm, Shoulder and Hand (DASH) score was the most utilised patient-reported function measure (n=11). Patient satisfaction was reported by eighteen studies but no single method was used consistently. Range of movement was the most frequent physical measure and was reported in all 91 studies. However, the methods of measurement and reporting varied, with seventeen different techniques being used. Other physical measures included grip and pinch strength and sensibility, again with variations in measurement protocols. The mean follow-up time ranged from 2 weeks to 17 years. Conclusions: There is little consistency in the reporting of outcomes for interventions in patients with Dupuytren’s disease, making it impossible to compare the efficacy of different treatment modalities. Although there are limitations to the existing generic patient reported outcomes measures, a combination of these together with a disease-specific questionnaire, and physical measures of active and passive individual joint Range of movement (ROM), grip and sensibility using standardised protocols should be used for future outcomes studies. As Dupuytren’s disease tends to recur following treatment as well as extend to involve other areas of the hand, follow-up times should be standardised and designed to capture both short and long term outcomes

One origin for metallo-β-lactamase activity, or two? An investigation assessing a diverse set of reconstructed ancestral sequences based on a sample of phylogenetic trees

This work was supported by BBSRC (grant BB/F016778/1)Bacteria use metallo-β-lactamase enzymes to hydrolyse lactam rings found in many antibiotics, rendering them ineffective. Metallo-β-lactamase activity is thought to be polyphyletic, having arisen on more than one occasion within a single functionally diverse homologous superfamily. Since discovery of multiple origins of enzymatic activity conferring antibiotic resistance has broad implications for the continued clinical use of antibiotics, we test the hypothesis of polyphyly further; if lactamase function has arisen twice independently, the most recent common ancestor (MRCA) is not expected to possess lactam-hydrolysing activity. Two major problems present themselves. Firstly, even with a perfectly known phylogeny, ancestral sequence reconstruction is error prone. Secondly, the phylogeny is not known, and in fact reconstructing a single, unambiguous phylogeny for the superfamily has proven impossible. To obtain a more statistical view of the strength of evidence for or against MRCA lactamase function, we reconstructed a sample of 98 MRCAs of the metallo-β-lactamases, each based on a different tree in a bootstrap sample of reconstructed phylogenies. InterPro sequence signatures and homology modelling were then used to assess our sample of MRCAs for lactamase functionality. Only 5 % of these models conform to our criteria for metallo-β-lactamase functionality, suggesting that the ancestor was unlikely to have been a metallo-β-lactamase. On the other hand, given that ancestral proteins may have had metallo-β-lactamase functionality with variation in sequence and structural properties compared with extant enzymes, our criteria are conservative, estimating a lower bound of evidence for metallo-β-lactamase functionality but not an upper bound.Publisher PDFPeer reviewe

Photocatalytic Degradation of Organic Pollutants in Water Using Graphene Oxide Composite

Developing sustainable and less-expensive technique is always challenging task in water treatment process. This chapter explores the recent development of photocatalysis technique in organic pollutant removal from the water. Particularly, advantages of graphene oxide in promoting the catalytic performance of semiconductor, metal nanoparticle and polymer based photocatalyst materials. Owing to high internal surface area and rapid electron conducting property of graphene oxide fostering as backbone scaffold for effective hetero-photocatalyst loading, and rapid photo-charge separation enables effective degradation of pollutant. This chapter summaries the recent development of graphene oxide composite (metal oxide, metal nanoparticle, metal chalcogenides, and polymers) in semiconductor photocatalysis process towards environmental remediation application

A Research Agenda for Helminth Diseases of Humans: Modelling for Control and Elimination

Mathematical modelling of helminth infections has the potential to inform policy and guide research for the control and elimination of human helminthiases. However, this potential, unlike in other parasitic and infectious diseases, has yet to be realised. To place contemporary efforts in a historical context, a summary of the development of mathematical models for helminthiases is presented. These efforts are discussed according to the role that models can play in furthering our understanding of parasite population biology and transmission dynamics, and the effect on such dynamics of control interventions, as well as in enabling estimation of directly unobservable parameters, exploration of transmission breakpoints, and investigation of evolutionary outcomes of control. The Disease Reference Group on Helminth Infections (DRG4), established in 2009 by the Special Programme for Research and Training in Tropical Diseases (TDR), was given the mandate to review helminthiases research and identify research priorities and gaps. A research and development agenda for helminthiasis modelling is proposed based on identified gaps that need to be addressed for models to become useful decision tools that can support research and control operations effectively. This agenda includes the use of models to estimate the impact of large-scale interventions on infection incidence; the design of sampling protocols for the monitoring and evaluation of integrated control programmes; the modelling of co-infections; the investigation of the dynamical relationship between infection and morbidity indicators; the improvement of analytical methods for the quantification of anthelmintic efficacy and resistance; the determination of programme endpoints; the linking of dynamical helminth models with helminth geostatistical mapping; and the investigation of the impact of climate change on human helminthiases. It is concluded that modelling should be embedded in helminth research, and in the planning, evaluation, and surveillance of interventions from the outset. Modellers should be essential members of interdisciplinary teams, propitiating a continuous dialogue with end users and stakeholders to reflect public health needs in the terrain, discuss the scope and limitations of models, and update biological assumptions and model outputs regularly. It is highlighted that to reach these goals, a collaborative framework must be developed for the collation, annotation, and sharing of databases from large-scale anthelmintic control programmes, and that helminth modellers should join efforts to tackle key questions in helminth epidemiology and control through the sharing of such databases, and by using diverse, yet complementary, modelling approaches

Phytoremediation of heavy metal-contaminated sites: Eco-environmental concerns, field studies, sustainability issues and future prospects

Environmental contamination due to heavy metals (HMs) is of serious ecotoxicological concern worldwide because of their increasing use at industries. Due to non-biodegradable and persistent nature, HMs cause serious soil/water pollution and severe health hazards in living beings upon exposure. HMs can be genotoxic, carcinogenic, mutagenic, and teratogenic in nature even at low concentration. They may also act as endocrine disruptors and induce developmental as well as neurological disorders and thus, their removal from our natural environment is crucial for the rehabilitation of contaminated sites. To cope with HM pollution, phytoremediation has emerged as a low-cost and eco-sustainable solution to conventional physico-chemical cleanup methods that require high capital investment and labor alter soil properties and disturb soil microflora. Phytoremediation is a green technology wherein plants and associated microbes are used to remediate HM-contaminated sites to safeguard the environment and protect public health. Hence, in view of the above, the present paper aims to examine the feasibility of phytoremediation as a sustainable remediation technology for the management of metals-contaminated sites. Therefore, this paper provides an in-depth review on both the conventional and novel phytoremediation approaches, evaluate their efficacy to remove toxic metals from our natural environment, explore current scientific progresses, field experiences and sustainability issues and revise world over trends in phytoremediation research for its wider recognition and public acceptance as a sustainable remediation technology for the management of contaminated sites in 21st century

Dietary phytochemicals, HDAC inhibition, and DNA damage/repair defects in cancer cells

Genomic instability is a common feature of cancer etiology. This provides an avenue for therapeutic intervention, since cancer cells are more susceptible than normal cells to DNA damaging agents. However, there is growing evidence that the epigenetic mechanisms that impact DNA methylation and histone status also contribute to genomic instability. The DNA damage response, for example, is modulated by the acetylation status of histone and non-histone proteins, and by the opposing activities of histone acetyltransferase and histone deacetylase (HDAC) enzymes. Many HDACs overexpressed in cancer cells have been implicated in protecting such cells from genotoxic insults. Thus, HDAC inhibitors, in addition to unsilencing tumor suppressor genes, also can silence DNA repair pathways, inactivate non-histone proteins that are required for DNA stability, and induce reactive oxygen species and DNA double-strand breaks. This review summarizes how dietary phytochemicals that affect the epigenome also can trigger DNA damage and repair mechanisms. Where such data is available, examples are cited from studies in vitro and in vivo of polyphenols, organosulfur/organoselenium compounds, indoles, sesquiterpene lactones, and miscellaneous agents such as anacardic acid. Finally, by virtue of their genetic and epigenetic mechanisms, cancer chemopreventive agents are being redefined as chemo- or radio-sensitizers. A sustained DNA damage response coupled with insufficient repair may be a pivotal mechanism for apoptosis induction in cancer cells exposed to dietary phytochemicals. Future research, including appropriate clinical investigation, should clarify these emerging concepts in the context of both genetic and epigenetic mechanisms dysregulated in cancer, and the pros and cons of specific dietary intervention strategies