keyword
MENU ▼
Read by QxMD icon Read
search

crystal structure

keyword
https://www.readbyqxmd.com/read/28723955/crystal-structure-and-functional-characterization-of-an-isoaspartyl-dipeptidase-cpsiada-from-colwellia-psychrerythraea-strain-34h
#1
Sun-Ha Park, Chang Woo Lee, Sung Gu Lee, Seung Chul Shin, Hak Jun Kim, Hyun Park, Jun Hyuck Lee
Isoaspartyl dipeptidase (IadA) is an enzyme that catalyzes the hydrolysis of an isoaspartyl dipeptide-like moiety, which can be inappropriately formed in proteins, between the β-carboxyl group side chain of Asp and the amino group of the following amino acid. Here, we have determined the structures of an isoaspartyl dipeptidase (CpsIadA) from Colwellia psychrerythraea, both ligand-free and that complexed with β-isoaspartyl lysine, at 1.85-Å and 2.33-Å resolution, respectively. In both structures, CpsIadA formed an octamer with two Zn ions in the active site...
2017: PloS One
https://www.readbyqxmd.com/read/28723891/the-lysosomal-potassium-channel-tmem175-adopts-a-novel-tetrameric-architecture
#2
Changkeun Lee, Jiangtao Guo, Weizhong Zeng, Sunghoon Kim, Ji She, Chunlei Cang, Dejian Ren, Youxing Jiang
TMEM175 is a lysosomal K(+) channel that is important for maintaining the membrane potential and pH stability in lysosomes. It contains two homologous copies of a six-transmembrane-helix (6-TM) domain, which has no sequence homology to the canonical tetrameric K(+) channels and lacks the TVGYG selectivity filter motif found in these channels. The prokaryotic TMEM175 channel, which is present in a subset of bacteria and archaea, contains only a single 6-TM domain and functions as a tetramer. Here, we present the crystal structure of a prokaryotic TMEM175 channel from Chamaesiphon minutus, CmTMEM175, the architecture of which represents a completely different fold from that of canonical K(+) channels...
July 19, 2017: Nature
https://www.readbyqxmd.com/read/28723868/screening-of-medicinal-plant-phytochemicals-as-natural-antagonists-of-p53-mdm2-interaction-to-reactivate-p53-functioning
#3
Muhammad Riaz, Usman A Ashfaq, Muhammad Qasim, Erum Yasmeen, Muhammad T Ul Qamar, Farooq Anwar
In most types of cancer, overexpression of murine double minute 2 (MDM2) often leads to inactivation of p53. The crystal structure of MDM2, with a 109-residue amino-terminal domain, reveals that MDM2 has a core hydrophobic region to which p53 binds as an amphipathic α helix. The interface depends on the steric complementarity between MDM2 and the hydrophobic region of p53. Especially, on p53's triad, amino acids Phe19, Trp23 and Leu26 bind to the MDM2 core. Results from studies suggest that the structural motif of both p53 and MDM2 can be attributed to similarities in the amphipathic α helix...
July 18, 2017: Anti-cancer Drugs
https://www.readbyqxmd.com/read/28723592/effects-of-near-infrared-radiation-on-dna-dls-and-atr-ftir-study
#4
Katarzyna Szymborska-Małek, Małgorzata Komorowska, Marlena Gąsior-Głogowska
We presume that the primary effect of Near Infrared (NIR) radiation on aqueous solutions of biological molecules concerns modification of hydrogen bonded structures mainly the global and the hydration shell water molecules. Since water has a significant influence on the DNA structure, we expect that the thermal stability of DNA could be modified by NIR radiation. The herring sperm DNA was exposed to NIR radiation (700-1100nm) for 5, 10, and 20min periods. The temperature dependent infrared measurements were done for the thin films formed on the diamond ATR crystal from evaporated DNA solutions exposed and unexposed to NIR radiation...
July 12, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28723557/crystal-structure-of-the-human-ribosome-in-complex-with-denr-mct-1
#5
Ivan B Lomakin, Elena A Stolboushkina, Anand T Vaidya, Chenguang Zhao, Maria B Garber, Sergey E Dmitriev, Thomas A Steitz
The repertoire of the density-regulated protein (DENR) and the malignant T cell-amplified sequence 1 (MCT-1/MCTS1) oncoprotein was recently expanded to include translational control of a specific set of cancer-related mRNAs. DENR and MCT-1 form the heterodimer, which binds to the ribosome and operates at both translation initiation and reinitiation steps, though by a mechanism that is yet unclear. Here, we determined the crystal structure of the human small ribosomal subunit in complex with DENR-MCT-1. The structure reveals the location of the DENR-MCT-1 dimer bound to the small ribosomal subunit...
July 18, 2017: Cell Reports
https://www.readbyqxmd.com/read/28723226/improving-the-quality-and-safety-of-frozen-muscle-foods-by-emerging-freezing-technologies-a-review
#6
Ximing Zhan, Da-Wen Sun, Zhiwei Zhu, Qi-Jin Wang
Freezing is one of the most widespread used preservation methods for meats including fish meat. Traditional freezing methods such as air blast freezing and cryogenic freezing could induce some quality deterioration such as damage to cell structure, increased drip loss and poor sensory value. Therefore, novel freezing methods have been developed to minimize the disadvantages of traditional freezing methods. This review describes the enhancement of quality attributes of muscle tissues frozen by novel freezing technologies, including high pressure freezing, electrically and magnetically assisted freezing, ultrasound assisted freezing and antifreeze protein...
July 19, 2017: Critical Reviews in Food Science and Nutrition
https://www.readbyqxmd.com/read/28723223/free-energy-of-binding-and-mechanism-of-interaction-for-the-meevd-tpr2a-peptide-protein-complex
#7
Mauro Lapelosa
The association between the MEEVD C-terminal peptide from the heat shock protein 90 (Hsp90) and tetratricopeptide repeat A (TPR2A) domain of the heat shock organizing protein (Hop) is a useful prototype to study the fundamental molecular details about the Hop-Hsp90 interaction. We study here the mechanism of binding/unbinding, and compute the standard binding free energy and potential of mean force for the association of the MEEVD peptide to the TPR2A domain using the Adaptive Biasing Force (ABF) methodology...
July 19, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28723190/in-search-of-the-ultimate-benzene-sensor-the-etqxbox-solution
#8
Jakub W Trzciński, Roberta Pinalli, Nicolò Riboni, Alessandro Pedrini, Federica Bianchi, Stefano Zampolli, Ivan Elmi, Chiara Massera, Franco Ugozzoli, Enrico Dalcanale
In this work we report a comprehensive study leading to the fabrication of a prototype sensor for environmental benzene monitoring. The required high selectivity and ppb-level sensitivity are obtained by coupling a silicon-integrated concentration unit containing the specifically designed EtQxBox cavitand to a miniaturized PID detector. In the resulting stand-alone sensor, the EtQxBox receptor acts at the same time as highly sensitive preconcentrator for BTEX and GC-like separation phase, allowing for the selective desorption of benzene over TEX...
April 28, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28723151/fusion-of-structure-and-ligand-based-methods-for-identification-of-novel-cdk2-inhibitors
#9
Priya Mahajan, Gousia Chashoo, Monika Gupta, Amit Kumar, Parvinder Pal Singh, Amit Nargotra
Cyclin dependent kinases plays a central role in cell cycle regulation which makes them a promising target with multifarious therapeutic potential. CDK2 regulates various events of the eukaryotic cell division cycle and the pharmacological evidences indicated that over expression of CDK2 causes abnormal cell-cycle regulation, which was directly associated with hyper proliferation of cancer cells. Therefore, CDK2 is regarded as a potential target molecule for anti-cancer medication. Thus to decline CDK2 activity by potential lead compounds has proved to be an effective treatment for cancer...
July 19, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/28723092/microwave-assisted-synthesis-of-diversely-substituted-quinoline-based-dihydropyridopyrimidine-and-dihydropyrazolopyridine-hybrids
#10
Daniel Insuasty, Rodrigo Abonia, Braulio Insuasty, Jairo Quiroga, Kenneth K Laali, Manuel Nogueras, Justo Cobo
An efficient, catalyst-free and one-pot three-component procedure for the synthesis of novel and nitrogen rich dihydropyrido[2,3-d]pyrimidines and dihydro-1H-pyrazolo[3,4-b]pyridines bearing a quinoline pharmacophore fragment is provided. Reactions proceeded in DMF under microwave irradiation of three-component mixtures of formyl-quinoline derivatives, primary heterocyclic amines and cyclic 1,3-diketones. Interestingly, when conventional heating at reflux was used for the starting 5-amino-1-phenylpyrazole, the corresponding aromatized pyrazolopyridines were obtained as the main products...
July 19, 2017: ACS Combinatorial Science
https://www.readbyqxmd.com/read/28723090/transformative-heterointerface-evolution-and-plasmonic-tuning-of-anisotropic-trimetallic-nanoparticles
#11
Mouhong Lin, Gyeong-Hwan Kim, Jae-Ho Kim, Jeong-Wook Oh, Jwa-Min Nam
Multi-component nanoparticles that incorporate multiple nano-crystal domains into a single particle represent an important class of material with highly tailorable structures and properties. The controlled synthesis of multi-component NPs with 3 or more components with the desired structure, particularly aniso-tropic structures, and property is, however, highly challenging. Here, we developed a polymer and galvanic replacement reac-tion-based transformative heterointerface evolution (THE) method to form and tune gold-copper-silver multi-metallic ani-sotropic nanoparticles (MAPs) with well-defined configurations, including structural order, uniformity and junction geometry, giving rise to extraordinarily high tunability in the structural design, synthesis and optical property of tri-metallic plasmonic nanoantenna structures...
July 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28723078/covalency-competition-in-the-quadruple-perovskite-cdcu3fe4o12
#12
Ikuya Yamada, Akihiko Takamatsu, Naoaki Hayashi, Hidekazu Ikeno
Cadmium ions (Cd(2+)) are similar to calcium ions (Ca(2+)) in size, whereas the Cd(2+) ions tend to form covalent bonds with the neighboring anions because of the high electronegativity. The covalent Cd-O bonds affect other metal-oxygen bonds, inducing drastic changes in crystal structures and electronic states. Herein, we demonstrate high-pressure synthesis, crystal structure, and properties of a new quadruple perovskite CdCu3Fe4O12. This compound exhibits an electronic phase transition accompanying a charge disproportionation of Fe ions without charge ordering below ∼200 K, unlike charge-disproportionation transition with rock-salt-type charge ordering for CaCu3Fe4O12...
July 19, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28722825/crystalline-%C3%AF-stack-containing-five-stereoisomers-insights-into-conformational-isomorphism-chirality-inversion-and-disorder
#13
Agnieszka Nowak-Krol, Merle Röhr, David Schmidt, Frank Würthner
An unprecedented crystal packing arrangement of a tetramethoxy-bay-substituted perylene bisimide (PBI) consists of three crystallographically independent molecules, i.e. an achiral (AC) PBI of saddle-shaped geometry along with two pairs of propeller-like twisted (P) and (M)enantiomeric PBI frameworks. All these five conformations are observed within a single π-stack revealing an intriguing packing sequence with an inversion of chirality from P to M via AC. Nudged elastic band calculations for the isolated molecule show that AC is a local minimum of the P to M interconversion path...
July 19, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28722742/characterization-of-hydrogen-bonding-motifs-in-proteins-hydrogen-elimination-monitoring-by-ultraviolet-photodissociation-mass-spectrometry
#14
Lindsay J Morrison, Wenrui Chai, Jake A Rosenberg, Graeme Henkelman, Jennifer S Brodbelt
Determination of structure and folding of certain classes of proteins remains intractable by conventional structural characterization strategies and has spurred the development of alternative methodologies. Mass spectrometry-based approaches have a unique capacity to differentiate protein heterogeneity due to the ability to discriminate populations, whether minor or major, featuring modifications or complexation with non-covalent ligands on the basis of m/z. Cleavage of the peptide backbone can be further utilized to obtain residue-specific structural information...
July 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28722450/two-new-sandwich-type-manganese-mn5-substituted-polyoxotungstates-syntheses-crystal-structures-electrochemistry-and-magnetic-properties
#15
Rakesh Gupta, Imran Khan, Firasat Hussain, A Martin Bossoh, Israël M Mbomekallé, Pedro de Oliveira, Masahiro Sadakane, Chisato Kato, Katsuya Ichihashi, Katsuya Inoue, Sadafumi Nishihara
Herein we report two pentanuclear Mn(II)-substituted sandwich-type polyoxotungstate complexes, [{Mn(bpy)}2Na(H2O)2(MnCl)2{Mn(H2O)}(AsW9O33)2](9-) and [{Mn(bpy)}2Na(H2O)2(MnCl){Mn(H2O)}2(SbW9O33)2](8-) (bpy = 2,2'-bipyridine), whose structures have been obtained by single-crystal X-ray diffraction (SCXRD), complemented by results obtained from elemental analysis, electrospray ionization mass spectrometry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. They consist of two [B-α-XW9O33](9-) subunits sandwiching a cyclic assembly of the hexagonal [{Mn(bpy)}2Na(H2O)2(MnCl)2{Mn(H2O)}](9+) and [{Mn(bpy)}2Na(H2O)2(MnCl){Mn(H2O)}2](10+) moieties, respectively, and represent the first pentanuclear Mn(II)-substituted sandwich-type polyoxometalates (POMs)...
July 19, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28722401/novel-xanthate-complexes-for-the-size-controlled-synthesis-of-copper-sulfide-nanorods
#16
Mundher Al-Shakban, Peter D Matthews, Geradius Deogratias, Paul D McNaughter, James Raftery, Inigo Vitorica-Yrezabal, Egid B Mubofu, Paul O'Brien
We present a simple, easily scalable route to monodisperse copper sulfide nanocrystals by the hot injection of a series of novel copper(I) xanthate single-source precursors [(PPh3)2Cu(S2COR)] (R = isobutyl, 2-methoxyethyl, 2-ethoxyethyl, 1-methoxy-2-propyl, 3-methoxy-1-butyl, and 3-methoxy-3-methyl-1-butyl), whose crystal structures are also reported. We show that the width of the obtained rods is dependent on the length of the xanthate chain, which we rationalize through a computational study, where we show that there is a relationship between the ground-state energy of the precursor and the copper sulfide rod width...
July 19, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28722277/in-situ-growth-and-wrapping-of-aminoanthraquinone-nanowires-within-3d-graphene-framework-as-high-performance-foldable-organic-cathode-for-lithium-ion-batteries
#17
Guanhui Yang, Fanxing Bu, Yanshan Huang, Yu Zhang, Imran Shakir, Yuxi Xu
Small conjugated carbonyl compounds are intriguing candidates of organic electrode materials because of their abundance, high theoretical capacity and adjustable molecular structure. However, their dissolution in aprotic electrolytes and poor conductivity eclipse them in terms of practical capacity, cycle life and rate capability. Herein, we report a foldable and binder-free nanocomposite electrode consisting of 2-aminoanthraquinone (AAQ) nanowires wrapping within three-dimensional (3D) graphene framework, which is prepared through antisolvent crystallization followed by a facile chemical reduction and self-assembly process...
July 19, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28722227/engineering-single-nanopores-on-gold-nanoplates-by-tuning-crystal-screw-dislocation
#18
Yueming Zhai, Fan Zhang, Bo Zhang, Xiaohu Gao
Compared with the large variety of solid gold nanostructures, synthetic approaches for their hollow counterparts are limited, largely confined to chemical and irradiation-based etching of preformed nanostructures. In particular, the preparation of through nanopore structures is extremely challenging. Here, a unique strategy for direct synthesis of gold nanopores in solution without the need for sacrificial templates or postsynthesis processing is reported. By controlling the degree of crystal screw dislocation, a single through pore with diameter ranging from sub-nanometer to tens of nanometers, in the center of large gold nanoplates, can be engineered with precision...
July 19, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28722076/the-anomalous-halogen-bonding-interactions-between-chlorine-and-bromine-with-water-in-clathrate-hydrates
#19
Hana Dureckova, Tom K Woo, Konstantin A Udachin, John A Ripmeester, Saman Alavi
Clathrate hydrate phases of Cl2 and Br2 guest molecules have been known for about 200 years. The crystal structure of these phases was recently re-determined with high accuracy by single crystal X-ray diffraction. In these structures, the water oxygen-halogen atom distances are determined to be shorter than the sum of the van der Waals radii, which indicates the action of some type of non-covalent interaction between the dihalogens and water molecules. Given that in the hydrate phases both lone pairs of each water oxygen atom are engaged in hydrogen bonding with other water molecules of the lattice, the nature of the oxygen-halogen interactions may not be the standard halogen bonds characterized recently in the solid state materials and enzyme-substrate compounds...
July 19, 2017: Faraday Discussions
https://www.readbyqxmd.com/read/28722040/a-new-set-of-cd-ii-coordination-polymers-with-mixed-ligands-of-dicarboxylate-and-pyridyl-substituted-diaminotriazine-selective-sorption-towards-co2-and-cationic-dyes
#20
Santanu Chand, Syed Meheboob Elahi, Arun Pal, Madhab C Das
On the basis of a mixed ligand system of L(NH2)2 (6-(pyridin-4-yl)-1,3,5-triazine-2,4-diamine) and dicarboxylic acids, three new Cd(ii) coordination polymers viz. {[Cd0.5(tdc)0.5(L(NH2)2)0.5(H2O)]·DMF·H2O}n (1), {[Cd0.5(bdc)0.5(L(NH2)2)(H2O)]·DMF·H2O}n (2), and {[Cd(ipa)(L(NH2)2)(DMF)]·H2O}n (3) (tdcH2 = thiophene-2,5-dicarboxylic acid, bdcH2 = benzene-1,4-dicarboxylic acid, ipaH2 = benzene-1,3-dicarboxylic acid) were synthesized under diverse reaction conditions and characterized by single crystal X-ray diffraction, PXRD, elemental analysis, IR spectroscopy and TGA...
July 19, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
keyword
keyword
3892
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"