keyword
MENU ▼
Read by QxMD icon Read
search

crystal structure transporter

keyword
https://www.readbyqxmd.com/read/28815927/metallofullerenol-inhibits-cellular-iron-uptake-by-inducing-transferrin-tetramerization
#1
Jinxia Li, Xueqing Xing, Baoyun Sun, Yuliang Zhao, Zhonghua Wu
Herein, A549 tumor cell proliferation was confirmed to be positively dependent on the concentration of Fe3+ or transferrin (Tf). Gd@C₈₂(OH)₂₂ or C₆₀(OH)₂₂ effectively inhibited the iron uptake and the subsequent proliferation of A549 cells. The conformation changes of Tf mixed with FeCl₃, GdCl₃, C₆₀(OH)₂₂ or Gd@C₈₂(OH)₂₂ were obtained by SAXS. The results demonstrate that Tf homodimers can be decomposed into monomers in the presence of FeCl₃, GdCl3 or C₆₀(OH)₂₂, but aggregated into tetramers in the presence of Gd@C₈₂(OH)₂₂...
August 16, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28814238/structural-insights-for-drugs-developed-for-phospholipase-d-enzymes
#2
Kimberly Stieglitz
BACKGROUND: In recent years human phospholipase D enzymes (PLD1 and PLD2 isozymes) have emerged as drug targets for various diseases such as cardiovascular disease, cancer, infectious diseases and neurodegenerative conditions such as Alzheimer's and Parkinson's disease. The interest in PLD as a drug target is due to the fact that PLD enzymes belong to a superfamily of phospholipases that are essential to intracellular and extracellular signaling. Many bioactive lipid signaling molecules are generated by these enzymes including phosphatidic and lysophosphatidic acid, arachidonic acid, and diacylglycerol (DAG)...
August 15, 2017: Current Drug Discovery Technologies
https://www.readbyqxmd.com/read/28812880/an-exceptionally-narrow-band-gap-%C3%A2-4-ev-silicate-predicted-in-the-cubic-perovskite-structure-basio3
#3
Hidenori Hiramatsu, Hitoshi Yusa, Ryo Igarashi, Yasuo Ohishi, Toshio Kamiya, Hideo Hosono
The electronic structures of 35 A(2+)B(4+)O3 ternary cubic perovskite oxides, including their hypothetical chemical compositions, were calculated by a hybrid functional method with the expectation that peculiar electronic structures and unique carrier transport properties suitable for semiconductor applications would be hidden in high-symmetry cubic perovskite oxides. We found unique electronic structures of Si-based oxides (A = Mg, Ca, Sr, and Ba, and B = Si). In particular, the unreported cubic BaSiO3 has a very narrow band gap (4...
August 16, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28811154/theoretical-study-on-electron-structure-and-charge-transport-properties-of-tetraazapentacene-derivatives
#4
Xiao-Dan Tang
By Means of Marcus electron transfer theory, the charge transport properties of tetraazapentacene (4N-PEN) derivatives were systematically explored. The reorganization energies were studied by both adiabatic potential-energy surfaces and normal mode analysis. The charge diffusion constants were evaluated from the random walk simulation. From the perspective of homology modeling, a selected 4N-PEN derivative without experimental crystal structure was built into three kinds of possible packing modes with reference to its relative analogues and then fully optimized...
June 23, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28809412/charging-assisted-structural-phase-transitions-in-monolayer-inse
#5
Liangzhi Kou, Aijun Du, Yandong Ma, Ting Liao, Changfeng Chen
A recently synthesized InSe monolayer exhibits highly promising electronic and transport properties; it also possesses intricate intralayer atomic bonding configurations that are conducive to modulations of crystal and electronic structures. Here we identify by first-principles calculations two new structural phases of monolayer InSe distinct from the experimentally synthesized β phase. The first, α phase, has the Se atom positions displaced relative to those in the β phase, and exhibits outstanding electronic properties similar to those of the β phase...
August 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28808284/molecular-rationale-behind-the-differential-substrate-specificity-of-bacterial-rnd-multi-drug-transporters
#6
Venkata Krishnan Ramaswamy, Attilio V Vargiu, Giuliano Malloci, Jürg Dreier, Paolo Ruggerone
Resistance-Nodulation-cell Division (RND) transporters AcrB and AcrD of Escherichia coli expel a wide range of substrates out of the cell in conjunction with AcrA and TolC, contributing to the onset of bacterial multidrug resistance. Despite sharing an overall sequence identity of ~66% (similarity ~80%), these RND transporters feature distinct substrate specificity patterns whose underlying basis remains elusive. We performed exhaustive comparative analyses of the putative substrate binding pockets considering crystal structures, homology models and conformations extracted from multi-copy μs-long molecular dynamics simulations of both AcrB and AcrD...
August 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28805826/violation-of-ohm-s-law-in-a-weyl-metal
#7
Dongwoo Shin, Yongwoo Lee, M Sasaki, Yoon Hee Jeong, Franziska Weickert, Jon B Betts, Heon-Jung Kim, Ki-Seok Kim, Jeehoon Kim
Ohm's law is a fundamental paradigm in the electrical transport of metals. Any transport signatures violating Ohm's law would give an indisputable fingerprint for a novel metallic state. Here, we uncover the breakdown of Ohm's law owing to a topological structure of the chiral anomaly in the Weyl metal phase. We observe nonlinear I-V characteristics in Bi0.96Sb0.04 single crystals in the diffusive limit, which occurs only for a magnetic-field-aligned electric field (E∥B). The Boltzmann transport theory with the charge pumping effect reveals the topological-in-origin nonlinear conductivity, and it leads to a universal scaling function of the longitudinal magnetoconductivity, which completely describes our experimental results...
August 14, 2017: Nature Materials
https://www.readbyqxmd.com/read/28801111/luminescence-resonance-energy-transfer-spectroscopy-of-atp-binding-cassette-proteins
#8
REVIEW
Maria E Zoghbi, Guillermo A Altenberg
The ATP-binding cassette (ABC) superfamily includes regulatory and transport proteins. Most human ABC exporters pump substrates out of cells using energy from ATP hydrolysis. Although major advances have been made toward understanding the molecular mechanism of ABC exporters, there are still many issues unresolved. During the last few years, luminescence resonance energy transfer has been used to detect conformational changes in real time, with atomic resolution, in isolated ABC nucleotide binding domains (NBDs) and full-length ABC exporters...
August 8, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28799375/comparison-of-liquid-state-anomalies-in-stillinger-weber-models-of-water-silicon-and-germanium
#9
Debdas Dhabal, Charusita Chakravarty, Valeria Molinero, Hemant K Kashyap
We use molecular dynamics simulations to compare and contrast the liquid-state anomalies in the Stillinger-Weber models of monatomic water (mW), silicon (Si), and germanium (Ge) over a fairly wide range of temperatures and densities. The relationships between structure, entropy, and mobility, as well as the extent of the regions of anomalous behavior, are discussed as a function of the degree of tetrahedrality. We map out the cascade of density, structural, pair entropy, excess entropy, viscosity, and diffusivity anomalies for these three liquids...
December 7, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28798966/can-exotic-disordered-stealthy-particle-configurations-tolerate-arbitrarily-large-holes
#10
G Zhang, F H Stillinger, S Torquato
The probability of finding a spherical cavity or "hole" of arbitrarily large size in typical disordered many-particle systems in the infinite-system-size limit (e.g., equilibrium liquid states) is non-zero. Such "hole" statistics are intimately linked to the thermodynamic and nonequilibrium physical properties of the system. Disordered "stealthy" many-particle configurations in d-dimensional Euclidean space [Doublestruck R](d) are exotic amorphous states of matter that lie between a liquid and crystal that prohibit single-scattering events for a range of wave vectors and possess no Bragg peaks [Torquato et al...
August 11, 2017: Soft Matter
https://www.readbyqxmd.com/read/28798487/epitaxial-thin-films-of-pyrochlore-iridate-bi2-xir2-yo7-%C3%AE-structure-defects-and-transport-properties
#11
W C Yang, Y T Xie, W K Zhu, K Park, A P Chen, Y Losovyj, Z Li, H M Liu, M Starr, J A Acosta, C G Tao, N Li, Q X Jia, J J Heremans, S X Zhang
While pyrochlore iridate thin films are theoretically predicted to possess a variety of emergent topological properties, experimental verification of these predictions can be obstructed by the challenge in thin film growth. Here we report on the pulsed laser deposition and characterization of thin films of a representative pyrochlore compound Bi2Ir2O7. The films were epitaxially grown on yttria-stabilized zirconia substrates and have lattice constants that are a few percent larger than that of the bulk single crystals...
August 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28796518/plasmonic-photovoltaic-cells-with-dual-functional-gold-silver-and-copper-halfshell-arrays
#12
Ling Wu, Gyu Min Kim, Hiroyasu Nishi, Tetsu Tatsuma
Solid-state photovoltaic cells based on plasmon-induced charge separation (PICS) have attracted growing attention during the last decade. However, the power conversion efficiency (PCE) of the previously reported devices, generally using dispersed metal nanoparticles as light absorbers, has not been sufficiently high. Here we report simpler plasmonic photovoltaic cells with interconnected Au, Ag, and Cu halfshell arrays deposited on SiO2@TiO2 colloidal crystals, which serve both as a plasmonic light absorber and as a current collector...
August 10, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28796493/crystal-growth-and-characterization-of-hgba2ca2cu3o8-%C3%AE-superconductors-with-the-highest-critical-temperature-at-ambient-pressure
#13
Bastien Loret, Anne Forget, Jean-Baptiste Moussy, Sylvie Poissonnet, Patrick Bonnaillie, Gaston Collin, Pierre Thuéry, Alain Sacuto, Dorothée Colson
We report an original procedure for the elaboration of very high-quality single crystals of superconducting HgBa2Ca2Cu3O8+δ mercury cuprates. These single crystals are unique, with very high-quality surface paving the way for spectroscopic, transport, and thermodynamic probes in order to understand the hole-doped cuprate phase diagram. Annealing allows one to optimize Tc up to Tc(max) = 133 K. The superconductivity transition width of about 2 K indicates that they are homogeneous. We show for the first time that, with adequate heat treatment, Hg-1223 can be largely underdoped and its doping level controlled...
August 10, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28792751/transformation-of-structure-electrical-conductivity-and-magnetism-in-aa-fe2o6-%C3%AE-a-sr-ca-and-a-sr
#14
Ram Krishna Hona, Ashfia Huq, Suresh Mulmi, Farshid Ramezanipour
The ability to control electrical properties and magnetism by varying the crystal structure using the effect of the A-site cation in oxygen-deficient perovskites has been studied in AA'Fe2O6-δ, where A = Sr, Ca and A' = Sr. The structure of Sr2Fe2O6-δ, synthesized at 1250 °C in air, contains dimeric units of FeO5 square pyramids separated by FeO6 octahedra. Here we show that this ordering scheme can be transformed by changing the A-site cations from Sr to Ca. This leads to a structure where layers of corner-sharing FeO6 octahedra are separated by chains of FeO4 tetrahedra...
August 9, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28790314/structural-and-functional-insights-into-the-lipopolysaccharide-abc-transporter-lptb2fg
#15
Haohao Dong, Zhengyu Zhang, Xiaodi Tang, Neil G Paterson, Changjiang Dong
The cell surface of most Gram-negative bacteria contains lipopolysaccharide that is essential for their viability and drug resistance. A 134-kDa protein complex LptB2FG is unique among ATP-binding cassette transporters because it extracts lipopolysaccharide from the external leaflet of the inner membrane and propels it along a filament that extends across the periplasm to directly deliver lipopolysaccharide into the external leaflet of the outer membrane. Here we report the crystal structure of the lipopolysaccharide transporter LptB2FG from Klebsiella pneumoniae, in which both LptF and LptG are composed of a β-jellyroll-like periplasmic domain and six α-helical segments in the transmembrane domain...
August 9, 2017: Nature Communications
https://www.readbyqxmd.com/read/28783328/single-crystal-time-of-flight-neutron-diffraction-and-magic-angle-spinning-nmr-spectroscopy-resolve-the-structure-and-1-h-and-7-li-dynamics-of-the-uranyl-peroxide-nanocluster-u60
#16
Travis A Olds, Mateusz Dembowski, Xiaoping Wang, Christina Hoffman, Todd M Alam, Sarah Hickam, Kristi L Pellegrini, Junhong He, Peter C Burns
Single-crystal time-of-flight neutron diffraction has provided atomic resolution of H atoms of H2O molecules and hydroxyl groups, as well as Li cations in the uranyl peroxide nanocluster U60. Solid-state magic-angle-spinning nuclear magnetic resonance (MAS NMR) spectroscopy was used to confirm the dynamics of these constituents, revealing the transportation of Li atoms and H2O through cluster walls. H atoms of hydroxyl units that are located on the cluster surface are involved in the transfer of H2O and Li cations from inside to outside and vice versa...
August 7, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28777578/extended-polymorphism-of-two-dimensional-material
#17
Masaro Yoshida, Jianting Ye, Yijin Zhang, Yasuhiko Imai, Shigeru Kimura, Akihiko Fujiwara, Terukazu Nishizaki, Norio Kobayashi, Masaki Nakano, Yoshihiro Iwasa
When controlling electronic properties of bulk materials, we usually assume that the basic crystal structure is fixed. However, in two-dimensional (2D) materials, atomic structure or polymorph is attracting growing interests as a controlling parameter to functionalize their properties. Various polymorphs can exist in transition metal dichalcogenides (TMDCs) from which 2D materials are generated, and polymorphism has drastic impacts on the electronic states. Here we report the discovery of an unprecedented polymorph of a TMDC 2D material...
August 4, 2017: Nano Letters
https://www.readbyqxmd.com/read/28777089/crystal-structure-of-the-putative-cytoplasmic-protein-stm0279-hcp2-from-salmonella-typhimurium
#18
Qing Peng Lin, Zeng Qiang Gao, Zhi Geng, Heng Zhang, Yu Hui Dong
STM0279 is a putative cytoplasmic protein from Salmonella typhimurium and was recently renamed haemolysin co-regulated protein 2 (Hcp2), with the neighbouring STM0276 being Hcp1. Both of them are encoded by the type VI secretion system (T6SS) of the Salmonella pathogenicity island 6 (SPI-6) locus and have high sequence identity. The Hcp proteins may function as a vital component of the T6SS nanotube and as a transporter and chaperone of diverse effectors from the bacterial T6SS. In this study, the crystal structure and the oligomeric state in solution of Hcp2 from S...
August 1, 2017: Acta Crystallographica. Section F, Structural Biology Communications
https://www.readbyqxmd.com/read/28776372/structural-stability-of-the-coiled-coil-domain-of-tumor-susceptibility-gene-tsg-101
#19
Jordan T White, Dmitri Toptygin, Randy Cohen, Natalie Murphy, Vincent J Hilser
The Tumor Susceptibility Gene-101 coiled coil domain (TSG101cc) is an integral component of the endosomal maturation machinery and cytokinesis, and also interacts with several transcription factors. The TSG101cc has been crystalized as a homotetramer but is known to interact with two of its binding partners as a heterotrimer. To investigate this apparent discrepancy, we examined the solution thermodynamics of the TSG101cc. Here, we use circular dichroism, differential scanning calorimetry, analytical ultracentrifugation, fluorescence, and structural thermodynamic analysis to investigate the structural stability and the unfolding of the TSG101cc...
August 4, 2017: Biochemistry
https://www.readbyqxmd.com/read/28774292/rosetta-broker-for-membrane-protein-structure-prediction-concentrative-nucleoside-transporter-3-and-corticotropin-releasing-factor-receptor-1-test-cases
#20
Dorota Latek
BACKGROUND: Membrane proteins are difficult targets for structure prediction due to the limited structural data deposited in Protein Data Bank. Most computational methods for membrane protein structure prediction are based on the comparative modeling. There are only few de novo methods targeting that distinct protein family. In this work an example of such de novo method was used to structurally and functionally characterize two representatives of distinct membrane proteins families of solute carrier transporters and G protein-coupled receptors...
August 3, 2017: BMC Structural Biology
keyword
keyword
111936
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"