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https://www.readbyqxmd.com/read/28448854/the-combined-use-of-analytical-tools-for-exploring-tetanus-toxin-and-tetanus-toxoid-structures
#1
Caroline Bayart, Sébastien Peronin, Elisa Jean, Joseph Paladino, Philippe Talaga, Marc Le Borgne
Aldehyde detoxification is a process used to convert toxin into toxoid for vaccine applications. In the case of tetanus toxin (TT), formaldehyde is used to obtain the tetanus toxoid (TTd), which is used either for the tetanus vaccine or as carrier protein in conjugate vaccines. Several studies have already been conducted to better understand the exact mechanism of this detoxification. Those studies led to the identification of a number of formaldehyde-induced modifications on lab scale TTd samples. To obtain greater insights of the changes induced by formaldehyde, we used three industrial TTd batches to identify repeatable modifications in the detoxification process...
April 4, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28448785/a-class-ii-myosin-is-required-for-growth-conidiation-cell-wall-integrity-and-pathogenicity-of-magnaporthe-oryzae
#2
Min Guo, Leyong Tan, Xiang Nie, Zhengguang Zhang
In eukaryotic organisms, myosin proteins are the major ring components that are involved in cytokinesis. To date, little is known about the biological functions of myosin proteins in Magnaporthe oryzae. In this study, insertional mutagenesis conducted in M. oryzae led to identification of Momyo2, a pathogenicity gene predicted to encode a class-II myosin protein homologous to Saccharomyces cerevisiae Myo1. According to qRT-PCR, Momyo2 is highly expressed during early infectious stage. When this gene was disrupted, the resultant mutant isolates were attenuated in virulence on rice and barley...
April 27, 2017: Virulence
https://www.readbyqxmd.com/read/28448625/structural-and-functional-studies-of-ferredoxin-and-oxygenase-components-of-3-nitrotoluene-dioxygenase-from-diaphorobacter-sp-strain-ds2
#3
Archana Kumari, Deepak Singh, S Ramaswamy, Gurunath Ramanathan
3-nitrotoluene dioxygenase (3NTDO) from Diaphorobacter sp. strain DS2 catalyses the conversion of 3-nitrotoluene (3NT) into a mixture of 3- and 4-methylcatechols with release of nitrite. We report here, X-ray crystal structures of oxygenase and ferredoxin components of 3NTDO at 2.9 Å and 2.4 Å, respectively. The residues responsible for nitrite release in 3NTDO were further probed by four single and two double mutations in the catalytic site of α-subunit of the dioxygenase. Modification of Val 350 to Phe, Ile 204 to Ala, and Asn258 to Val by site directed mutagenesis resulted in inactive enzymes revealing the importance of these residues in catalysis...
2017: PloS One
https://www.readbyqxmd.com/read/28448016/zebrafish-in-situ-spinal-cord-preparation-for-electrophysiological-recordings-from-spinal-sensory-and-motor-neurons
#4
Rosa L Moreno, Megan Josey, Angeles B Ribera
Zebrafish, first introduced as a developmental model, have gained popularity in many other fields. The ease of rearing large numbers of rapidly developing organisms, combined with the embryonic optical clarity, served as initial compelling attributes of this model. Over the past two decades, the success of this model has been further propelled by its amenability to large-scale mutagenesis screens and by the ease of transgenesis. More recently, gene-editing approaches have extended the power of the model. For neurodevelopmental studies, the zebrafish embryo and larva provide a model to which multiple methods can be applied...
April 18, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28447092/the-co-dehydrogenase-accessory-protein-coot-is-a-novel-nickel-binding-protein
#5
J Timm, C Brochier-Armanet, J Perard, B Zambelli, S Ollagnier-de-Choudens, S Ciurli, C Cavazza
In Rhodospirillum rubrum, maturation of Carbon Monoxide Dehydrogenase (CODH) requires three accessory proteins, CooC, CooT and CooJ, dedicated to nickel insertion into the active site, which is constituted by a distorted [NiFe3S4] cubane coordinated with a mononuclear Fe site. CooC is an ATPase proposed to provide the energy required for the maturation process, while CooJ is described as a metallochaperone with 16 histidines and 2 cysteines at the C-terminus, likely involved in metal binding and/or storage...
April 27, 2017: Metallomics: Integrated Biometal Science
https://www.readbyqxmd.com/read/28446611/unraveling-amino-acid-residues-critical-for-allosteric-potentiation-of-%C3%AE-4-3-%C3%AE-2-2-type-nicotinic-acetylcholine-receptor-responses
#6
Ze-Jun Wang, Farah Deba, Tasnim S Mohamed, David C Chiara, Kara Ramos, Ayman K Hamouda
Neuronal nicotinic acetylcholine receptors (nAChRs) are promising drug targets to manage several neurological disorders and nicotine addiction. Growing evidence indicates that positive allosteric modulators (PAMs) of nAChRs improve pharmacological specificity by binding to unique sites present only in a subpopulation of nAChRs. Furthermore, nAChR PAMs such as NS9283 and CMPI have been shown to potentiate responses of (α4)3(β2)2 but not (α4)2(β2)3 nAChR isoforms. This selective potentiation underlines that the α4:α4 interface, which is present only in the (α4)3(β2)2 nAChR, is an important and promising drug target...
April 26, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28446593/creating-cell-type-specific-mutants-by-enhancer-mutagenesis
#7
Stephen Crews
Cell signaling plays an essential role in development, and knowledge of the identities of the cells sending the signal is critical. This can be a challenge, since signaling pathways and ligands are commonly used at multiple times and in multiple cell types during development. One solution to this problem is to create cell type-specific mutants using CRISPR/Cas9 to mutate enhancers that control different patterns of expression. In this issue of Genes & Development, Rogers and colleagues (pp. 634-638) provide the first use of this method in Drosophila to solve a long-standing issue in patterning of the embryonic central nervous system...
April 1, 2017: Genes & Development
https://www.readbyqxmd.com/read/28445826/exposure-to-fine-particulate-matter-causes-oxidative-and-methylated-dna-damage-in-young-adults-a-longitudinal-study
#8
Ching-Huang Lai, Han-Bin Huang, Yue-Cune Chang, Ting-Yao Su, Ying-Chuan Wang, Gia-Chi Wang, Jia-En Chen, Chin-Sheng Tang, Trong-Neng Wu, Saou-Hsing Liou
An increased understanding is needed of the physiological effects and plausible biological mechanisms that link PM2.5 (particulate matter with an aerodynamic diameter below 2.5μm) exposure to mortality and morbidities such as atherosclerosis and respiratory disease. PM2.5 causes carcinogenic health effects. Biomonitoring in humans has suggested that 8-oxo-7, 8-dihydro-2-deoxyguanosine (8-oxodG) and N7-methylguanine (N7-MeG) are correlated with oxidative and methylated DNA damage. Thus, it is meaningful to explore the mechanisms of mutagenesis and carcinogenesis associated with oxidative and methylated DNA damage by simultaneously measuring these two markers...
April 23, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28445592/polo-like-kinase-1-is-a-proviral-host-factor-for-hepatitis-b-virus-replication
#9
Ahmed M Diab, Adrien Foca, Floriane Fusil, Thomas Lahlali, Pascal Jalaguier, Fouzia Amirache, Lia N'Guyen, Nathalie Isorce, François-Loïc Cosset, Fabien Zoulim, Ourania M Andrisani, David Durantel
Chronic Hepatitis B Virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC) and current treatments for CHB and HCC are perfectible. Herein, we identified cellular Serine/Threonine Polo-like-kinase 1 (PLK1) as a positive effector of HBV replication. The aim of this study was to demonstrate the proviral role of PLK1 in HBV biosynthesis and validate PLK1 inhibition a potential antiviral strategy. To this end, we employed physiologically relevant HBV infection models of Primary Human Hepatocytes (PHH) and differentiated HepaRG cells, in conjunction with pharmacologic PLK1 inhibitors, siRNA-mediated knockdown, and overexpression of constitutively active PLK1 (PLK1(CA) )...
April 26, 2017: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/28443661/engineering-of-rumb-toward-a-green-catalyst-for-carbene-insertion-reactions
#10
Matthew W Wolf, David A Vargas, Nicolai Lehnert
The small, stable heme protein myoglobin (Mb) was modified through cofactor substitution and mutagenesis to develop a new catalyst for carbene transfer reactions. The native heme was removed from wild-type Mb and several Mb His64 mutants (H64D, H64A, H64V), and the resulting apoproteins were reconstituted with ruthenium mesoporphyrin IX (RuMpIX). The reconstituted proteins (RuMb) were characterized by UV-vis and circular dichroism spectroscopy and were used as catalysts for the N-H insertion of aniline derivatives and the cyclopropanation of styrene derivatives...
April 26, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28443644/a-reciprocal-regulatory-loop-between-taz-yap-and-g-protein-g%C3%AE-s-regulates-schwann-cell-proliferation-and-myelination
#11
Yaqi Deng, Lai Man Natalie Wu, Shujun Bai, Chuntao Zhao, Haibo Wang, Jincheng Wang, Lingli Xu, Masahide Sakabe, Wenhao Zhou, Mei Xin, Q Richard Lu
Schwann cell (SC) myelination in the peripheral nervous system is essential for motor function, and uncontrolled SC proliferation occurs in cancer. Here, we show that a dual role for Hippo effectors TAZ and YAP in SC proliferation and myelination through modulating G-protein expression and interacting with SOX10, respectively. Developmentally regulated mutagenesis indicates that TAZ/YAP are critical for SC proliferation and differentiation in a stage-dependent manner. Genome-wide occupancy mapping and transcriptome profiling reveal that nuclear TAZ/YAP promote SC proliferation by activating cell cycle regulators, while targeting critical differentiation regulators in cooperation with SOX10 for myelination...
April 26, 2017: Nature Communications
https://www.readbyqxmd.com/read/28443127/transcriptome-analysis-of-a-female-sterile-mutant-fsm-in-chinese-cabbage-brassica-campestris-ssp-pekinensis
#12
Shengnan Huang, Zhiyong Liu, Chengyu Li, Runpeng Yao, Danyang Li, Li Hou, Xiang Li, Wenjie Liu, Hui Feng
Female-sterile mutants are ideal materials for studying pistil development in plants. Here, we identified a female-sterile mutant fsm in Chinese cabbage. This mutant, which exhibited stable inheritance, was derived from Chinese cabbage DH line 'FT' using a combination of isolated microspore culture and ethyl methanesulfonate mutagenesis. Compared with the wild-type line 'FT,' the fsm plants exhibited pistil abortion, and floral organs were also relatively smaller. Genetic analysis indicated that the phenotype of fsm is controlled by a single recessive nuclear gene...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28442765/the-gpr139-reference-agonists-1a-and-7c-and-tryptophan-and-phenylalanine-share-a-common-binding-site
#13
Anne Cathrine Nøhr, Willem Jespers, Mohamed A Shehata, Leonard Floryan, Vignir Isberg, Kirsten Bayer Andersen, Johan Åqvist, Hugo Gutiérrez-de-Terán, Hans Bräuner-Osborne, David E Gloriam
GPR139 is an orphan G protein-coupled receptor expressed in the brain, in particular in the habenula, hypothalamus and striatum. It has therefore been suggested that GPR139 is a possible target for metabolic disorders and Parkinson's disease. Several surrogate agonist series have been published for GPR139. Two series published by Shi et al. and Dvorak et al. included agonists 1a and 7c respectively, with potencies in the ten-nanomolar range. Furthermore, Isberg et al. and Liu et al. have previously shown that tryptophan (Trp) and phenylalanine (Phe) can activate GPR139 in the hundred-micromolar range...
April 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28441873/identification-and-characterization-of-a-secondary-sodium-binding-site-and-the-main-selectivity-determinants-in-the-human-concentrative-nucleoside-transporter-3
#14
C Arimany-Nardi, A Claudio-Montero, A Viel-Oliva, P Schmidtke, C Estarellas, X Barril, A Bidon-Chanal, M Pastor-Anglada
The family of concentrative Na(+):nucleoside cotransporters in humans is constituted by three subtypes, namely hCNT1, hCNT2 and hCNT3. Besides their different nucleoside selectivity, hCNT1 and hCNT2 have a Na(+):nucleoside stoichiometry of 1:1, while for hCNT3 it is of 2:1. This distinct stoichiometry of subtype 3 might hint the existence of a secondary sodium-binding site that is not present in the other two subtypes, but to date their three-dimensional structures remain unknown and the residues implicated in Na(+) binding are unclear...
April 25, 2017: Molecular Pharmaceutics
https://www.readbyqxmd.com/read/28441491/a-naturally-occurring-isoform-specific-probe-for-highly-selective-and-sensitive-detection-of-human-cytochrome-p450-3a5
#15
Jing-Jing Wu, Yun-Feng Cao, Liang Feng, Yu-Qi He, James Y Hong, Tong-Yi Dou, Ping Wang, Da-Cheng Hao, Guang-Bo Ge, Ling Yang
Cytochrome P450 (CYP) 3A5 characterized with polymorphic and extensive expression in multiple tissues is the most important P450 enzyme among the minor CYP3A isoforms. However, a selective and sensitive probe for CYP3A5 remains unavailable. In this study, we identified and characterized a naturally-occurring lignan 12 (Schisantherin E) as an isoform-specific probe for selective detection of CYP3A5 activity in complex biological samples. With thorough characterization including LC-MS and NMR, we found that 12 can be metabolized by CYP3A5 to generate a major metabolite 2-O-demethylated 12...
April 25, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28441004/insights-into-the-mechanisms-by-which-clostridial-neurotoxins-discriminate-between-gangliosides
#16
Joshua R Burns, Gregory S Lambert, Michael R Baldwin
Botulinum neurotoxins (BoNTs) and Tetanus neurotoxin (TeNT) are the causative agents of the paralytic diseases botulism and tetanus, respectively. Entry of toxins into neurons is mediated through initial interactions with gangliosides, followed by binding to a protein co-receptor. Herein we aimed to understand the mechanism through which individual neurotoxins recognize the carbohydrate motif of gangliosides. Using cell-based and in vitro binding assays, in conjunction with structure-driven site directed mutagenesis, a conserved hydrophobic residue within the BoNTs that contributes to both affinity and specificity towards Sia5-containing gangliosides was identified...
April 25, 2017: Biochemistry
https://www.readbyqxmd.com/read/28440457/%C3%AE-catenin-induces-expression-of-prohibitin-gene-in-acute-leukemic-cells
#17
Dong Min Kim, Hanbit Jang, Myung Geun Shin, Jeong-Hoon Kim, Sang Mo Shin, Sang-Hyun Min, Il-Chul Kim
Prohibitin (PHB) is a multifunctional protein conserved in eukaryotic systems and shows various expression levels in tumor cells. However, regulation of PHB is not clearly understood. Here, we focused on the regulation of PHB expression by Wnt signaling, one of dominant regulatory signals in various leukemic cells. High mRNA levels of PHB were found in half of clinical leukemia samples. PHB expression was increased by inhibition of the MAPK pathway and decreased by activation of EGF signal. Although cell proliferating signals downregulated the transcription of PHB, treatment with lithium chloride, an analog of the Wnt signal, induced PHB level in various cell types...
April 25, 2017: Oncology Reports
https://www.readbyqxmd.com/read/28439853/crispr-cas-mediated-in-planta-gene-targeting
#18
Simon Schiml, Friedrich Fauser, Holger Puchta
The recent emergence of the CRISPR/Cas system has boosted the possibilities for precise genome engineering approaches throughout all kingdoms of life. The most common application for plants is targeted mutagenesis, whereby a Cas9-mediated DNA double-strand break (DSB) is repaired by mutagenic nonhomologous end joining (NHEJ). However, the site-specific alteration of a genomic sequence or integration of a transgene relies on the precise repair by homologous recombination (HR) using a suitable donor sequence: this poses a particular challenge in plants, as NHEJ is the preferred repair mechanism for DSBs in somatic tissue...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28439038/pseudomonas-aeruginosa-derived-rhamnolipids-and-other-detergents-modulate-colony-morphotype-and-motility-in-the-burkholderia-cepacia-complex
#19
Steve P Bernier, Courtney Hum, Xiang Li, George A O'Toole, Nathan Magarvey, Michael G Surette
Competitive interactions mediated by released chemicals (e.g. toxins) are prominent in multispecies communities, but their effect at subinhibitory concentrations on susceptible bacteria is poorly understood. Although Pseudomonas aeruginosa and species of the Burkholderia cepacia complex (Bcc) can exist together as a co-infection in cystic fibrosis airways, P. aeruginosa toxins can kill Bcc species in vitro Consequently, these bacteria become an ideal in vitro model system to study the impact of sublethal levels of toxins on the biology of typical susceptible bacteria such as the Bcc when exposed to P...
April 24, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28438927/the-role-of-psl-genes-in-antibiotic-tolerance-of-adherent-pseudomonas-aeruginosa
#20
Keiji Murakami, Tsuneko Ono, Darija Viducic, Yoko Somiya, Reiko Kariyama, Kenji Hori, Takashi Amoh, Katsuhiko Hirota, Hiromi Kumon, Matthew R Parsek, Yoichiro Miyake
Bacteria attached to a surface are generally more tolerant to antibiotics than their planktonic counterparts, even without the formation of a biofilm. The mechanism of antibiotic tolerance in biofilm communities is multifactorial, and the genetic backgound underlying this antibiotic tolerance has not yet been fully elucidated. Using transposon mutagenesis, we isolated a mutant with reduced tolerance to biapenem (relative to the wild-type) from adherent cells. Sequencing analysis revealed a mutation in the pslL gene, which is a part of the polysaccharide biosynthesis operon...
April 24, 2017: Antimicrobial Agents and Chemotherapy
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