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https://www.readbyqxmd.com/read/29151266/crystal-structure-and-catalytic-characterization-of-the-dehydrogenase-reductase-sdr-family-member-4-dhrs4-from-caenorhabditis-elegans
#1
Michael Kisiela, Annette Faust, Bettina Ebert, Edmund Maser, Axel J Scheidig
The human dehydrogenase/reductase SDR family member 4 (DHRS4) is a tetrameric protein that is involved in the metabolism of several aromatic carbonyl compounds, steroids and bile acids. The only invertebrate DHRS4 that has been characterized to date is that from the model organism Caenorhabditis elegans. We have previously cloned and initially characterized this protein that was recently annotated as DHRS4_CAEEL in the UniProtKB database. Crystallization and X-ray diffraction studies of the full-length DHRS4_CAEEL protein in complex with diacetyl revealed its tetrameric structure and showed that two subunits are connected via an intermolecular disulfide bridge that is formed by N-terminal cysteine residues (Cys5) of each protein chain, which increases the enzymatic activity...
November 19, 2017: FEBS Journal
https://www.readbyqxmd.com/read/29151218/structures-of-dynamic-protein-complexes-hybrid-techniques-to-study-map-kinase-complexes-and-the-escrt-system
#2
Wolfgang Peti, Rebecca Page, Evzen Boura, Bartosz Różycki
The integration of complementary molecular methods (including X-ray crystallography, NMR spectroscopy, small angle X-ray/neutron scattering, and computational techniques) is frequently required to obtain a comprehensive understanding of dynamic macromolecular complexes. In particular, these techniques are critical for studying intrinsically disordered protein regions (IDRs) or intrinsically disordered proteins (IDPs) that are part of large protein:protein complexes. Here, we explain how to prepare IDP samples suitable for study using NMR spectroscopy, and describe a novel SAXS modeling method (ensemble refinement of SAXS; EROS) that integrates the results from complementary methods, including crystal structures and NMR chemical shift perturbations, among others, to accurately model SAXS data and describe ensemble structures of dynamic macromolecular complexes...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29150730/racial-differences-in-symptom-management-experiences-during-breast-cancer-treatment
#3
Cleo A Samuel, Jennifer Schaal, Linda Robertson, Jemeia Kollie, Stephanie Baker, Kristin Black, Olive Mbah, Crystal Dixon, Katrina Ellis, Eugenia Eng, Fatima Guerrab, Nora Jones, Amanda Kotey, Claire Morse, Jessica Taylor, Vickie Whitt, Samuel Cykert
PURPOSE: Racial disparities in cancer treatment-related symptom burden are well documented and linked to worse treatment outcomes. Yet, little is known about racial differences in patients' treatment-related symptom management experiences. Such understanding can help identify modifiable drivers of symptom burden inequities. As part of the Cancer Health Accountability for Managing Pain and Symptoms (CHAMPS) study, we examined racial differences in symptom management experiences among Black and White breast cancer survivors (BCS)...
November 18, 2017: Supportive Care in Cancer: Official Journal of the Multinational Association of Supportive Care in Cancer
https://www.readbyqxmd.com/read/29150603/bacterially-derived-synthetic-mimetics-of-mammalian-oligomannose-prime-antibody-responses-that-neutralize-hiv-infectivity
#4
Ralph Pantophlet, Nino Trattnig, Sasha Murrell, Naiomi Lu, Dennis Chau, Caitlin Rempel, Ian A Wilson, Paul Kosma
Oligomannose-type glycans are among the major targets on the gp120 component of the HIV envelope protein (Env) for broadly neutralizing antibodies (bnAbs). However, attempts to elicit oligomannose-specific nAbs by immunizing with natural or synthetic oligomannose have so far not been successful, possibly due to B cell tolerance checkpoints. Here we design and synthesize oligomannose mimetics, based on the unique chemical structure of a recently identified bacterial lipooligosaccharide, to appear foreign to the immune system...
November 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/29150596/forming-a-three-dimensional-porous-organic-network-via-solid-state-explosion-of-organic-single-crystals
#5
Seo-Yoon Bae, Dongwook Kim, Dongbin Shin, Javeed Mahmood, In-Yup Jeon, Sun-Min Jung, Sun-Hee Shin, Seok-Jin Kim, Noejung Park, Myoung Soo Lah, Jong-Beom Baek
Solid-state reaction of organic molecules holds a considerable advantage over liquid-phase processes in the manufacturing industry. However, the research progress in exploring this benefit is largely staggering, which leaves few liquid-phase systems to work with. Here, we show a synthetic protocol for the formation of a three-dimensional porous organic network via solid-state explosion of organic single crystals. The explosive reaction is realized by the Bergman reaction (cycloaromatization) of three enediyne groups on 2,3,6,7,14,15-hexaethynyl-9,10-dihydro-9,10-[1,2]benzenoanthracene...
November 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/29150515/loop-of-streptomyces-feruloyl-esterase-plays-an-important-role-in-its-activity-of-releasing-ferulic-acid-from-biomass
#6
Misugi Uraji, Haruka Tamura, Eiichi Mizohata, Jiro Arima, Kun Wan, Ken'ichi Ogawa, Tsuyoshi Inoue, Tadashi Hatanaka
Feruloyl esterases (FAEs) are key enzymes required for the production of ferulic acid from agricultural biomass. Previously, we identified and characterized R18, an FAE from Streptomyces cinnamoneus NBRC 12852, which showed no sequence similarity with the known FAEs. To determine the region involved in its catalytic activity, we constructed chimeric enzymes using R18 and its homolog (TH2-18) from S. cinnamoneus strain TH-2. Although R18 and TH2-18 showed 74% identity in their primary sequence, the recombinant proteins of these two FAEs (rR18 and rTH2-18) showed very different specific activities toward ethyl ferulate...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29149603/structural-basis-of-mitochondrial-transcription-initiation
#7
Hauke S Hillen, Yaroslav I Morozov, Azadeh Sarfallah, Dmitry Temiakov, Patrick Cramer
Transcription in human mitochondria is driven by a single-subunit, factor-dependent RNA polymerase (mtRNAP). Despite its critical role in both expression and replication of the mitochondrial genome, transcription initiation by mtRNAP remains poorly understood. Here, we report crystal structures of human mitochondrial transcription initiation complexes assembled on both light and heavy strand promoters. The structures reveal how transcription factors TFAM and TFB2M assist mtRNAP to achieve promoter-dependent initiation...
November 16, 2017: Cell
https://www.readbyqxmd.com/read/29149597/structural-basis-for-shelterin-bridge-assembly
#8
Jin-Kwang Kim, Jinqiang Liu, Xichan Hu, Clinton Yu, Kyle Roskamp, Banumathi Sankaran, Lan Huang, Elizabeth A Komives, Feng Qiao
Telomere elongation through telomerase enables chromosome survival during cellular proliferation. The conserved multifunctional shelterin complex associates with telomeres to coordinate multiple telomere activities, including telomere elongation by telomerase. Similar to the human shelterin, fission yeast shelterin is composed of telomeric sequence-specific double- and single-stranded DNA-binding proteins, Taz1 and Pot1, respectively, bridged by Rap1, Poz1, and Tpz1. Here, we report the crystal structure of the fission yeast Tpz1(475-508)-Poz1-Rap1(467-496) complex that provides the structural basis for shelterin bridge assembly...
November 16, 2017: Molecular Cell
https://www.readbyqxmd.com/read/29149595/sterol-oxidation-mediates-stress-responsive-vms1-translocation-to-mitochondria
#9
Jason R Nielson, Eric K Fredrickson, T Cameron Waller, Olga Zurita Rendón, Heidi L Schubert, Zhenjian Lin, Christopher P Hill, Jared Rutter
Vms1 translocates to damaged mitochondria in response to stress, whereupon its binding partner, Cdc48, contributes to mitochondrial protein homeostasis. Mitochondrial targeting of Vms1 is mediated by its conserved mitochondrial targeting domain (MTD), which, in unstressed conditions, is inhibited by intramolecular binding to the Vms1 leucine-rich sequence (LRS). Here, we report a 2.7 Å crystal structure of Vms1 that reveals that the LRS lies in a hydrophobic groove in the autoinhibited MTD. We also demonstrate that the oxidized sterol, ergosterol peroxide, is necessary and sufficient for Vms1 localization to mitochondria, through binding the MTD in an interaction that is competitive with binding to the LRS...
November 16, 2017: Molecular Cell
https://www.readbyqxmd.com/read/29149594/conversion-of-bim-bh3-from-activator-to-inhibitor-of-bak-through-structure-based-design
#10
Jason M Brouwer, Ping Lan, Angus D Cowan, Jonathan P Bernardini, Richard W Birkinshaw, Mark F van Delft, Brad E Sleebs, Adeline Y Robin, Ahmad Wardak, Iris K Tan, Boris Reljic, Erinna F Lee, W Douglas Fairlie, Melissa J Call, Brian J Smith, Grant Dewson, Guillaume Lessene, Peter M Colman, Peter E Czabotar
Certain BH3-only proteins transiently bind and activate Bak and Bax, initiating their oligomerization and the permeabilization of the mitochondrial outer membrane, a pivotal step in the mitochondrial pathway to apoptosis. Here we describe the first crystal structures of an activator BH3 peptide bound to Bak and illustrate their use in the design of BH3 derivatives capable of inhibiting human Bak on mitochondria. These BH3 derivatives compete for the activation site at the canonical groove, are the first engineered inhibitors of Bak activation, and support the role of key conformational transitions associated with Bak activation...
November 16, 2017: Molecular Cell
https://www.readbyqxmd.com/read/29149568/individual-atomic-imaging-of-multiple-dopant-sites-in-as-doped-si-using-spectro-photoelectron-holography
#11
Kazuo Tsutsui, Tomohiro Matsushita, Kotaro Natori, Takayuki Muro, Yoshitada Morikawa, Takuya Hoshii, Kuniyuki Kakushima, Hitoshi Wakabayashi, Kouichi Hayashi, Fumihiko Matsui, Toyohiko Kinoshita
The atomic scale characterization of dopant atoms in semiconductor devices to establish correlations with the electrical activation of these atoms is the essential to the advancement of contemporary semiconductor process technology. Spectro-photoelectron holography combined with first-principles simulations can determine the local three-dimensional atomic structures of dopant elements, which in turn affect their electronic states. In the work reported herein, this technique was used to examine arsenic (As) atoms doped into a silicon (Si) crystal...
November 17, 2017: Nano Letters
https://www.readbyqxmd.com/read/29149559/core-shell-microstructure-induced-synergistic-effect-for-efficient-water-droplet-formation-and-cloud-seeding-application
#12
Yanlong Tai, Haoran Liang, Nabil El Hadri, Ali M Abshaev, Buzgigit M Huchinaev, Steve Griffiths, Mustapha Jouiad, Linda Zou
Cloud-seeding materials as a promising water-augmentation technology have drawn more attention recently. We designed and synthesized a novel type of core/shell NaCl/TiO2 (CSNT) particles with controlled particle size, which successfully adsorbed more water vapor (~ 295 times at low relative humidity, 20 % RH) than that of pure NaCl, deliquesced at lower environmental RH of 62 - 66 % than the hygroscopic point (hg.p., 75 % RH) of NaCl, and formed larger water droplets ~ 6 - 10 times of its original measured size area, whereas the pure NaCl still remained as crystal at the same condition...
November 17, 2017: ACS Nano
https://www.readbyqxmd.com/read/29149546/the-photophysical-and-photoacoustic-properties-of-quadrupolar-borondifluoride-curcuminoid-dyes
#13
Stephanie Bellinger, Maryam Hatamimoslehabadi, Seema Bag, Farha Mithila, Jeffrey La, Mathieu Frennete, Samir Laoui, David Szalda, Chandra Yelleswarapu, Jonathan Rochford
The synthesis and characterization of a series of donor-π-acceptor-π-donor (D-A-D) curcuminoid molecules are here presented incorporating π-extended aryl and electron-donating amino terminal functionalization. Computational evaluation shows these molecules possess quadrupolar character with the lowest energy transitions displaying high molar extinction coefficients with broad tunability through manipulation of terminal donating groups. Consistent with their quadrupolar nature, these molecules show varying degrees of solvatochromic behavior in both their absorption and emission spectra which has been analyzed by Lippert-Mataga and Kamlet-Taft analysis...
November 17, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29149501/the-weakly-coordinating-tris-trichlorosilyl-silyl-anion
#14
Marian Olaru, Maxie F Hesse, Elena Rychagova, Sergey Ketkov, Stefan Mebs, Jens Beckmann
Closely following the procedure for the preparation of the base-stabilized dichlorosilylene complex NHCDipp∙SiCl2 by Roesky and Stalke et al. (Angew. Chem. Int. Ed. 2009, 48, 5683-5686), besides the reported by-product [NHCDipp-H+∙∙∙Cl-], few crystals of the salt [NHCDipp-H∙∙∙Cl∙∙∙H-NHCDipp]Si(SiCl3)3 were isolated and characterized by X-ray crystallography (NHCDipp = N,N-di(2,6-isopropylphenyl)-imidazo-2-ylidene). They feature the weakly-coordinating anion Si(SiCl3)3-, which was more rationally obtained in high yields upon deprotonation of conjugate Brønsted acid HSi(SiCl3)3 with NHCDipp or PMP (PMP = 1,2,2,6,6-pentamethylpiperidine)...
November 17, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29149423/structural-and-visible-near%C3%A2-infrared-optical-properties-of-cr-doped-tio2-for-colored-cool-pigments
#15
Le Yuan, Xiaolong Weng, Ming Zhou, Qingyong Zhang, Longjiang Deng
Chromium-doped TiO2 pigments were synthesized via a solid-state reaction method and studied with X-ray diffraction, SEM, XPS, and UV-VIS-NIR reflectance spectroscopy. The incorporation of Cr(3+) accelerates the transition from the anatase phase to the rutile phase and compresses the crystal lattice. Moreover, the particle morphology, energy gap, and reflectance spectrum of Cr-doped TiO2 pigments is affected by the crystal structure and doping concentration. For the rutile samples, some of the Cr(3+) ions are oxidized to Cr(4+) after sintering at a high temperature, which leads to a strong near-infrared absorption band due to the (3)A2 → (3) T1 electric dipole-allowed transitions of Cr(4+)...
November 17, 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/29149232/stabilized-electrically-induced-helfrich-deformation-and-enhanced-color-tuning-in-cholesteric-liquid-crystals
#16
Meina Yu, Huai Yang, Deng-Ke Yang
When subjected to an AC electric field perpendicular to its layers, the cholesteric planar state may undergo a periodic layer undulation, known as the Helfrich deformation, which generates a color change of the reflected light. The Helfrich deformation of regular cholesteric liquid crystals is, however, unstable and easily taken over by the focal conic state, and thus the color tuning range is narrow. We demonstrated that the Helfrich deformation can be stabilized in a large electric field region by doping a bent dimer with an anomalously small bend elastic constant and dispersing a small amount of polymer network...
November 17, 2017: Soft Matter
https://www.readbyqxmd.com/read/29149126/pharmacogenomics-principles-and-relevance-to-oncology-nursing%C3%A2
#17
Crystal H Dodson
BACKGROUND: Pharmacogenomics is the fastest growing field in precision medicine. Based on current use, oncology encompasses the largest share of the precision medicine market, necessitating that oncology nurses understand the principles of pharmacogenomics and how it affects clinical practice.
. OBJECTIVES: This article will define precision medicine and pharmacogenomics and will provide examples of pharmacogenomic tests, including those associated with tumor markers, and nursing implications...
December 1, 2017: Clinical Journal of Oncology Nursing
https://www.readbyqxmd.com/read/29149072/different-inhibitory-potencies-of-oseltamivir-carboxylate-zanamivir-and-several-tannins-on-bacterial-and-viral-neuraminidases-as-assessed-in-a-cell-free-fluorescence-based-enzyme-inhibition-assay
#18
Stefanie Quosdorf, Anja Schuetz, Herbert Kolodziej
Neuraminidaseis a key enzyme in the life cycle of influenza viruses and is present in some bacterial pathogens. We here assess the inhibitory potency of plant tannins versus clinically used inhibitors on both a viral and a bacterial model neuraminidase by applying the 2'-(4-methylumbelliferyl)-α-d-N-acetylneuraminic acid (MUNANA)-based activity assay. A range of flavan-3-ols, ellagitannins and chemically defined proanthocyanidin fractions was evaluated in comparison to oseltamivir carboxylate and zanamivir for their inhibitory activities against viral influenza A (H1N1) and bacterial Vibrio cholerae neuraminidase (VCNA)...
November 17, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29148803/hsdhodh-microdomain-membrane-interactions-are-influenced-by-the-lipid-composition
#19
Eduardo Festozo Vicente, Indra Dev Sahu, Edson Crusca, Luis Guilherme Mansor Basso, Claudia Elisabeth Munte, Antonio Jose Costa-Filho, Gary A Lorigan, Eduardo Maffud Maffud Cilli
Human dihydroorotate dehydrogenase (HsDHODH) enzyme has been studied as selective target for inhibitors to block the enzyme activity, intending to prevent proliferative diseases. The N-terminal microdomain seems to play an important role in the enzyme function. However, the molecular mechanism of action and dynamics of this region are not totally understood yet. This study analyzes the interaction and conformation in model membranes of HsDHODH microdomain using peptide analogues containing the paramagnetic amino acid TOAC at strategic positions...
November 17, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29148797/nigegladines-a-c-three-thymoquinone-dimers-from-nigella-glandulifera
#20
Jie Tian, Chao Han, Wen-Hua Guo, Yong Yin, Xiao-Bing Wang, Hong-Bin Sun, He-Quan Yao, Yong Yang, Chen Wang, Chang Liu, Ming-Hua Yang, Ling-Yi Kong
Nigegladines A-C (1-3), three thymoquinone dimers, were isolated from the seeds of Nigella glandulifera. Racemic 1 possesses a unique tricyclo[5.4.0.1(2,6)]dodecane carbon skeleton, and compounds 2 and 3 are two unusual diterpenoid alkaloids with indole cores. Their structures were determined by extensive spectroscopic analyses, and that of 1 was confirmed by single-crystal X-ray diffraction. Both (+)-1 and (-)-1 exhibited significant protective effects against hypoxia/reoxygenation-induced H9c2 myocardial cell injury...
November 17, 2017: Organic Letters
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