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https://www.readbyqxmd.com/read/28743172/modelling-nutritional-mutualisms-challenges-and-opportunities-for-data-integration
#1
REVIEW
Teresa J Clark, Colleen A Friel, Emily Grman, Yair Shachar-Hill, Maren L Friesen
Nutritional mutualisms are ancient, widespread, and profoundly influential in biological communities and ecosystems. Although much is known about these interactions, comprehensive answers to fundamental questions, such as how resource availability and structured interactions influence mutualism persistence, are still lacking. Mathematical modelling of nutritional mutualisms has great potential to facilitate the search for comprehensive answers to these and other fundamental questions by connecting the physiological and genomic underpinnings of mutualisms with ecological and evolutionary processes...
July 25, 2017: Ecology Letters
https://www.readbyqxmd.com/read/28743168/calorie-restriction-reverses-age-related-alteration-of-cavernous-neurovascular-structure-in-the-rat
#2
A Limanjaya, K-M Song, M-J Choi, K Ghatak, N N Minh, D H Kang, J Ock, G N Yin, H Y Chung, J-K Ryu, J-K Suh
Calorie restriction (CR) refers to a reduction of calorie intake without compromising essential nutrients to avoid malnutrition. CR has been established as a non-genetic method of altering longevity and attenuating biological changes associated with aging. Aging is also an important risk factor for erectile dysfunction. The aim of this study was to examine whether CR diet can reverse the age-related alterations of erectile tissue in the aged rat. Four groups of rats were used: young rats (7 months) + ad libitum, aged rats (22 months) + ad libitum, young rats + CR diet, and aged rats + CR diet...
July 25, 2017: Andrology
https://www.readbyqxmd.com/read/28743089/understanding-the-interaction-of-concanavalin-a-with-mannosyl-glycoliposomes-a-surface-plasmon-resonance-and-fluorescence-study
#3
Catalina Sandoval-Altamirano, Susana A Sanchez, Nancy F Ferreyra, German Gunther
The specificity of carbohydrate-protein interaction is a key factor in many biological processes and it is the foundation of technologies using glycoliposomes in drug delivery. The incorporation of glycolipids in vesicles is expected to increase their specificity toward particular targets such as lectins; however, the degree of exposure of the carbohydrate moiety at the liposome surface is a crucial parameter to be considered in the interaction. Herein we report the synthesis of mannose derivatives with one or two hydrophobic chains of different length, designed with the purpose of modifying the degree of exposure of the mannose when they were incorporated into liposomes...
July 18, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28743071/prediction-of-protein-structural-class-for-low-similarity-sequences-using-chou-s-pseudo-amino-acid-composition-and-wavelet-denoising
#4
Bin Yu, Lifeng Lou, Shan Li, Yusen Zhang, Wenying Qiu, Xue Wu, Minghui Wang, Baoguang Tian
Prediction of protein structural class plays an important role in protein structure and function analysis, drug design and many other biological applications. Prediction of protein structural class for low-similarity sequences is still a challenging task. Based on the theory of wavelet denoising, this paper presents a novel method of prediction of protein structural class for the first time. Firstly, the features of the protein sequence are extracted by using Chou's pseudo amino acid composition (PseAAC). Then the extracted feature information is denoised by two-dimensional (2D) wavelet...
July 14, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28742966/the-decisive-role-of-hydrophobicity-on-the-effect-of-alkylammonium-chlorides-on-protein-stability-a-terahertz-spectroscopic-finding
#5
Debasish Das Mahanta, Rajib Kumar Mitra, Nirnay Samanta
Many biologically important processes involve a subtle interplay between Columbic and hydrophobic interactions among molecular groups with water. A comprehensive understanding of such processes, specially while occurring simultaneously in the same molecule is of practical importance. In this contribution we report the ultrafast (sub-ps to ps) collective hydrogen bond dynamics of water in the extended hydration layers in a series of alkylammonium chloride salts using THz time domain spectroscopic (TTDS) technique (0...
July 25, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28742492/from-mad-honey-to-hypotensive-agents-the-grayanoid-diterpenes
#6
James R Hanson
The toxicity of Rhododendron species and other members of the Ericaceae which is due to the grayanoid diterpenes, is described. Their structures, biogenesis and biological activity is reviewed.
September 1, 2016: Science Progress
https://www.readbyqxmd.com/read/28742480/from-ca%C3%A3-eh%C3%A3-to-a-commercial-sweetener-the-diterpenoid-glycosides-of-stevia-rebaudiana
#7
James R Hanson
The isolation, structure elucidation, chemistry, biosynthesis and biological activity of the sweet steviol glycosides from Stevia rebaudiana, are reviewed.
December 1, 2016: Science Progress
https://www.readbyqxmd.com/read/28742365/divergent-synthesis-of-polycyclic-indolines-copper-catalyzed-cascade-reactions-of-propargylic-carbamates-and-indoles
#8
Tian-Ren Li, Liang-Qiu Lu, Ya-Ni Wang, Bao-Cheng Wang, Wen-Jing Xiao
Polycyclic indolines are the common and core structural motif of many indole alkaloids that usually exhibit biological activities. Here, we describe two copper-catalyzed cascade reactions between propargylic carbamates and indoles. By doing so, one-step and divergent synthesis of structurally distinct polycyclic indolines, quinoline-fused indolines, C(3a)-indolyl furoindolines, and pyrroloindolines was achieved in high synthetic efficiency and selectivity.
July 25, 2017: Organic Letters
https://www.readbyqxmd.com/read/28742349/exploring-the-sponge-consortium-plakortis-symbiotica-xestospongia-deweerdtae-as-a-potential-source-of-antimicrobial-compounds-and-probing-the-pharmacophore-for-antituberculosis-activity-of-smenothiazole-a-by-diverted-total-synthesis
#9
Carlos Jiménez-Romero, Joanna E Rode, Yeiry M Pérez, Scott G Franzblau, Abimael D Rodríguez
Fractionation of the bioactive CHCl3-MeOH (1:1) extracts obtained from two collections of the sponge consortium Plakortis symbiotica-Xestospongia deweerdtae from Puerto Rico provided two new plakinidone analogues, designated as plakinidone B (2) and plakinidone C (3), as well as the known plakinidone (1), plakortolide F (4), and smenothiazole A (5). The structures of 1-5 were characterized on the basis of 1D and 2D NMR spectroscopic, IR, UV, and HRMS analysis. The absolute configurations of plakinidones 2 and 3 were established through chemical correlation methods, VCD/ECD experiments, and spectroscopic data comparisons...
July 25, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28742347/cationic-and-anionic-impact-on-the-electronic-structure-of-liquid-water
#10
Zhong Yin, Ludger Inhester, Sreevidya Thekku Veedu, Wilson Quevedo, Annette Pietzsch, Philippe Wernet, Gerrit Groenhof, Alexander Foehlisch, Helmut Grubmüller, Simone Agnes Techert
Hydration shells around ions are crucial for many fundamental biological and chemical processes. Their local physico-chemical properties are quite different from bulk water, and hard to probe experimentally. We address this problem by combining soft X-ray spectroscopy using a liquid jet and molecular dynamics (MD) simulations together with ab initio electronic structure calculations to elucidate the water-ion interaction in an MgCl2 solution at the molecular level. Our results reveal that salt ions mainly affect the electronic properties of water molecules in close vicinity and that the oxygen K-edge X-ray emission spectrum of water molecules in the first solvation shell differs significantly from bulk water...
July 25, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28742046/a-fast-algorithm-for-analysis-of-molecular-communication-in-artificial-synapse
#11
Bilgesu A Bilgin, Ozgur B Akan
In this paper we analyse molecular communications (MC) in a proposed artificial synapse (AS), whose main difference from biological synapses (BSs) is that it is closed, i.e., transmitter molecules cannot diffuse out from AS. Such a setup has both advantages and disadvantages. Besides higher structural stability, being closed, AS never runs out of transmitters. Thus, MC in AS is disconnected from outer environment, which is very desirable for possible intra-body applications. On the other hand, clearance of transmitters from AS has to be achieved by transporter molecules on the presynaptic membrane of AS...
July 21, 2017: IEEE Transactions on Nanobioscience
https://www.readbyqxmd.com/read/28742020/symmetry-broken-and-rebroken-during-the-atp-hydrolysis-cycle-of-the-mitochondrial-hsp90-trap1
#12
Daniel Elnatan, Miguel Betegon, Yanxin Liu, Theresa Ramelot, Michael A Kennedy, David A Agard
Hsp90 is a homodimeric ATP-dependent molecular chaperone that remodels its substrate "client" proteins, facilitating their folding and activating them for biological function. Despite decades of research, the mechanism connecting ATP hydrolysis and chaperone function remains elusive. Particularly puzzling has been the apparent lack of cooperativity in hydrolysis of the ATP in each protomer. A crystal structure of the mitochondrial Hsp90, TRAP1, revealed that the catalytically active state is closed in a highly-strained asymmetric conformation...
July 25, 2017: ELife
https://www.readbyqxmd.com/read/28742018/dynamic-structure-of-locomotor-behavior-in-walking-fruit-flies
#13
Alexander Y Katsov, Limor Freifeld, Mark Horowitz, Seppe Kuehn, Thomas R Clandinin
The function of the brain is unlikely to be understood without an accurate description of its output, yet the nature of movement elements and their organization remains an open problem. Here, movement elements are identified from dynamics of walking in flies, using unbiased criteria. On one time scale, dynamics of walking are consistent over hundreds of milliseconds, allowing elementary features to be defined. Over longer periods, walking is well described by a stochastic process composed of these elementary features, and a generative model of this process reproduces individual behavior sequences accurately over seconds or longer...
July 25, 2017: ELife
https://www.readbyqxmd.com/read/28741966/the-connections-of-wnt-pathway-components-with-cell-cycle-and-centrosome-side-effects-or-a-hidden-logic
#14
Vítězslav Bryja, Igor Červenka, Lukáš Čajánek
Wnt signaling cascade has developed together with multicellularity to orchestrate the development and homeostasis of complex structures. Wnt pathway components - such as β-catenin, Dishevelled (DVL), Lrp6, and Axin-- are often dedicated proteins that emerged in evolution together with the Wnt signaling cascade and are believed to function primarily in the Wnt cascade. It is interesting to see that in recent literature many of these proteins are connected with cellular functions that are more ancient and not limited to multicellular organisms - such as cell cycle regulation, centrosome biology, or cell division...
July 25, 2017: Critical Reviews in Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28741935/super-photostable-phosphole-based-dye-for-multiple-acquisition-stimulated-emission-depletion-imaging
#15
Chenguang Wang, Masayasu Taki, Yoshikatsu Sato, Aiko Fukazawa, Tetsuya Higashiyama, Shigehiro Yamaguchi
As stimulated emission depletion (STED) microscopy can provide structural details of cells with an optical resolution beyond the diffraction limit, it has become an indispensable tool in cell biology. However, the intense STED laser beam usually causes rapid photobleaching of the employed fluorescent dyes, which significantly limits the utility of STED microscopy from a practical perspective. Herein we report a new design of super-photostable dye, PhoxBright 430 (PB430), comprising a fully ring-fused π-conjugated skeleton with an electron-accepting phosphole P-oxide unit...
July 25, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28741898/development-of-a-new-structural-class-of-broadly-acting-hcv-non-nucleoside-inhibitors-leading-to-the-discovery-of-mk-8876
#16
Casey C McComas, Anandan Palani, Wei Chang, M Katharine Holloway, Charles A Lesburg, Peng Li, Nigel Liverton, Peter T Meinke, David B Olsen, Xuanjia Peng, Richard M Soll, Ajay Ummat, Jie Wu, Jin Wu, Nicolas Zorn, Steven W Ludmerer
Studies directed at developing a broadly acting non-nucleoside inhibitor of HCV NS5B led to the discovery of a novel structural class of 5-aryl benzofurans that simultaneously interact with both the palm I and palm II binding regions. An initial candidate was potent in vitro against HCV GT1a and GT1b replicons, and induced multi-log reductions in HCV viral load when orally dosed to chronic GT1 infected chimpanzees. However, in vitro potency losses against clinically relevant GT1a variants prompted a further effort to develop compounds with sustained potency across a broader array of HCV genotypes and mutants...
July 25, 2017: ChemMedChem
https://www.readbyqxmd.com/read/28741876/discovery-of-novel-potent-muscarinic-m3-receptor-antagonists-with-proper-plasma-stability-by-structural-recombination-of-marketed-m3-antagonists
#17
Zuojuan Xiang, Jun Liu, Hongbin Sun, Xiaoan Wen
The marketed long-acting M3 antagonists for treatment of chronic obstructive pulmonary disease have inappropriate plasma stability (either overstable or excessively unstable), which causes substantial systemic exposure or poor patient compliance. To discover novel M3 antagonists with proper plasma stability, we synthesized and biologically evaluated a series of chiral quaternary ammonium salts of pyrrolidinol esters, which were designed by structural recombination of the marketed M3 antagonists. As a result, two novel potent M3 antagonists, (R/S)-3-[2-hydroxy-2,2-di(thiophen-2-yl)acetoxy]-1,1-dimethylpyrrolidinium bromides (1 a: Ki =0...
July 25, 2017: ChemMedChem
https://www.readbyqxmd.com/read/28741725/cell-derived-micro-environment-helps-dental-pulp-stem-cells-promote-dental-pulp-regeneration
#18
Xuexin Zhang, Hui Li, Jingjing Sun, Xiangyou Luo, Hefeng Yang, Li Xie, Bo Yang, Weihua Guo, Weidong Tian
OBJECTIVES: The function of the dental pulp is closely connected to the extracellular matrix (ECM) structure, and ECM has received significant attention due to its biological functions for regulating cells. As such, the interaction between the ECM niche and cells is worth exploring for potential clinical uses. MATERIALS AND METHODS: In this study, dental pulp stem cell (DPSC)-derived ECM (DPM) was prepared through cell culture and decellularization to function as the cell niche, and changes in DPSC behaviour and histological analysis of dental pulp tissue regeneration were evaluated following the DPM culture...
July 25, 2017: Cell Proliferation
https://www.readbyqxmd.com/read/28741707/photophysical-and-photochemical-properties-of-naturally-cccurring-normelinonine-f-and-melinonine-f-alkaloids-and-structurally-related-n-2-and-or-n-9-methyl-%C3%AE-carboline-derivatives
#19
Federico A O Rasse-Suriani, Fernando S García-Einschlag, Matías Rafti, Tobías Schmidt De León, Pedro M David Gara, Rosa Erra-Balsells, Franco M Cabrerizo
In the present work, we have synthesized and fully characterized the photophysical and photochemical properties of a selected group of N-methyl-β-carboline derivatives (9-methyl-β-carbolines and iodine salts of 2-methyl- and 2,9-dimethyl-β-carbolinium) in aqueous solutions, in the pH-range 4.0 - 14.5. Moreover, despite the quite extensive studies reported in the literature regarding the overall photophysical behaviour of N-unsubstituted βCs, this work constitutes the first full and unambiguous characterization of anionic species of N-unsubstituted βCs (norharmane, harmane and harmine), present in aqueous solution under highly alkaline conditions (pH > 13...
July 25, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28741315/a-mass-spectrometry-and-dft-study-of-pyrithione-complexes-with-transition-metals-in-the-gas-phase
#20
Matias Butler, Gabriela M Cabrera
2-mercaptopyridine N-oxide (pyrithione, PTOH) along with several transition metal ions forms coordination compounds displaying notable biological activities. Gas-phase complexes formed between pyrithione and Manganese (II), Cobalt (II), Nickel (II), Copper (II) and Zinc (II) were investigated by infusion in the electrospray source of a quadrupole-time of flight mass spectrometer. Remarkably, positive ion mode spectra displayed the singly charged metal adduct ion [C10 H8 MN2 O2 S2 ](2+) ([M(PTO)2 ](+•) or [M(DPTO)](+•) ), where DPTO is dipyrithione, 2,2'-dithiobis(pyridine N-oxide), among the most abundant peaks, implying a change in the oxidation state of whether the metal ion or the ligands...
July 24, 2017: Journal of Mass Spectrometry: JMS
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