Read by QxMD icon Read

Single molecule

Annekathrin Widmann, Marc Artinger, Lukas Biesinger, Kathrin Boepple, Christina Peters, Jana Schlechter, Mareike Selcho, Andreas S Thum
Memory formation is a highly complex and dynamic process. It consists of different phases, which depend on various neuronal and molecular mechanisms. In adult Drosophila it was shown that memory formation after aversive Pavlovian conditioning includes-besides other forms-a labile short-term component that consolidates within hours to a longer-lasting memory. Accordingly, memory formation requires the timely controlled action of different neuronal circuits, neurotransmitters, neuromodulators and molecules that were initially identified by classical forward genetic approaches...
October 2016: PLoS Genetics
Yin-Shan Meng, Shang-Da Jiang, Bing-Wu Wang, Song Gao
Single-molecule magnets (SMMs) can retain their magnetization status preferentially after removal of the magnetic field below a certain temperature. The unique property, magnetic bistable status, enables the molecule-scale SMM to become the next-generation high-density information storage medium. SMMs' new applications are also involved in high-speed quantum computation and molecular spintronics. The development of coordination chemistry, especially in transition metal (3d) and lanthanide (4f) complexes, diversifies SMMs by introducing new ones...
October 21, 2016: Accounts of Chemical Research
Oriana Brea, Ines Corral Perez, Otilia Mo, Manuel Yañez, Ibon Alkorta, Jose Elguero
Through the use of high-level ab initio and density functional calculations we have shown that 1,8-diBeX-naphthalene (X = H, F, Cl, CN, CF₃, C(CF₃)₃) derivatives behave as anion sponges, very much as 1,8-bis(dimethylamino)naphthalene derivatives behave as proton sponges. The electron deficient nature of the BeX substituents, which favors strong charge transfer from the anion towards the former, results into anion affinities which are among the largest ones reported in the literature for single neutral molecules...
October 21, 2016: Chemistry: a European Journal
Philipp Leinen, Matthew F B Green, Taner Esat, Christian Wagner, F Stefan Tautz, Ruslan Temirov
Considering organic molecules as the functional building blocks of future nanoscale technology, the question of how to arrange and assemble such building blocks in a bottom-up approach is still open. The scanning probe microscope (SPM) could be a tool of choice; however, SPM-based manipulation was until recently limited to two dimensions (2D). Binding the SPM tip to a molecule at a well-defined position opens an opportunity of controlled manipulation in 3D space. Unfortunately, 3D manipulation is largely incompatible with the typical 2D-paradigm of viewing and generating SPM data on a computer...
October 2, 2016: Journal of Visualized Experiments: JoVE
Satoshi Habuchi, Takuya Yamamoto, Yasuyuki Tezuka
We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis...
September 26, 2016: Journal of Visualized Experiments: JoVE
Gil Henkin, Daniel Berard, Francis Stabile, Marjan Shayegan, Jason S Leith, Sabrina R Leslie
We present a dynamically adjustable nanofluidic platform for formatting the conformations of and visualizing the interaction kinetics between biomolecules in solution, offering new time resolution and control of the reaction processes. This platform extends Convex Lens-induced Confinement (CLiC), a technique for imaging molecules under confinement, by introducing a system for in-situ modification of the chemical environment; this system uses a deep microchannel to diffusively exchange reagents within the nanoscale imaging region, whose height is fixed by a nanopost array...
October 21, 2016: Analytical Chemistry
Robbert D A Weren, Arjen R Mensenkamp, Michiel Simons, Astrid Eijkelenboom, Aisha S Sie, Hicham Ouchene, Monique van Asseldonk, Encarna B Gomez-Garcia, Marinus J Blok, Joanne A de Hullu, Marcel R Nelen, Alexander Hoischen, Johan Bulten, Bastiaan B J Tops, Nicoline Hoogerbrugge, En Marjolijn J L Ligtenberg
With the recent introduction of Poly(ADP-ribose) polymerase (PARP) inhibitors, a promising novel therapy has become available for ovarian carcinoma patients with inactivating BRCA1 or BRCA2 mutations in their tumour. To select patients who may benefit from these treatments, assessment of the mutation status of BRCA1 and BRCA2 in the tumour is required. For reliable evaluation of germline and somatic mutations in these genes in DNA derived from formalin-fixed, paraffin-embedded (FFPE) tissue, we have developed a single molecule molecular inversion probe (smMIP)-based targeted next generation sequencing (NGS) approach...
October 21, 2016: Human Mutation
Dian-Qiu Lv, Shang-Wu Liu, Jian-Hua Zhao, Bang-Jun Zhou, Shao-Peng Wang, Hui-Shan Guo, Yuan-Yuan Fang
Viroids are plant-pathogenic molecules made up of single-stranded circular non-coding RNAs. How replicating viroids interfere with host silencing remains largely unknown. In this study, we investigated the effects of a nuclear-replicating Potato spindle tuber viroid (PSTVd) on interference with plant RNA silencing. Using transient induction of silencing in GFP transgenic Nicotiana benthamiana plants (line 16c), we found that PSTVd replication accelerated GFP silencing and increased Virp1 mRNA, which encodes bromodomain-containing viroid-binding protein 1 and is required for PSTVd replication...
October 21, 2016: Scientific Reports
Michel Alain Cuendet, Harel Weinstein, Michael V LeVine
Allostery plays a fundamental role in most biological processes. However, little theory is available to describe it outside of two-state models. Here we use a statistical mechanical approach to show that the allosteric coupling between two collective variables is not a single number, but instead a two-dimensional thermodynamic coupling function that is directly related to the mutual information from information theory and the copula density function from probability theory. On this basis, we demonstrate how to quantify the contribution of specific energy terms to this thermodynamic coupling function, enabling an approximate decomposition that reveals the mechanism of allostery...
October 21, 2016: Journal of Chemical Theory and Computation
Ho Cheol Jeong, Suk Hyun Lim, Dae Won Cho, Sung Hong Kim, Patrick S Mariano
Single electron transfer (SET) promoted photoaddition reactions of secondary N-α-trimethylsilyl-N-alkylamines to C60 were explored to gain a deeper understanding of the mechanistic pathways followed and to expand the library of novel types of organofullerenes that can be generated using this approach. The results show that photoreactions of 10% EtOH-toluene solutions containing C60 and N-α-trimethylsilyl-N-alkylamines produce either aminomethyl-1,2-dihydrofullerenes or symmetric fulleropyrrolidines as major products depending on the nature of alkyl substituents...
October 21, 2016: Organic & Biomolecular Chemistry
Gang Li, Mengyu Shen, Shuai Le, Yinling Tan, Ming Li, Xia Zhao, Wei Shen, Yuhui Yang, Jing Wang, Hongbin Zhu, Shu Li, Xiancai Rao, Fuquan Hu, Shuguang Lu
As a third-generation sequencing method, single-molecule real-time (SMRT) technology provides long read length, and it is well suited for re-sequencing projects and de novo assembly. In this study, Pseudomonas aeruginosa PA1 was characterized and re-sequenced using SMRT technology. PA1 was also subjected to genomic, comparative, and pan-genomic analyses. The multi-drug resistant strain PA1 possesses a 6,498,072 bp genome and a sequence type of ST-782. The genome of PA1 was also visualized, and the results revealed the details of general genome annotations, virulence factors, regulatory proteins, secretion system proteins, type II toxin-antitoxin pairs, and genomic islands...
October 20, 2016: Bioscience Reports
Francesca Esposito, Ilaria Carli, Claudia Del Vecchio, Lijia Xu, Angela Corona, Nicole Grandi, Dario Piano, Elias Maccioni, Simona Distinto, Cristina Parolin, Enzo Tramontano
BACKGROUND: Despite the availability of effective antiretroviral therapies, drugs for HIV-1 treatment with new mode of action are still needed. An innovative approach is aimed to identify dual HIV-1 inhibitors, small molecules that can inhibit two viral functions at the same time. Rhubarb, originated from Rheum palmatum L. and Rheum officinale Baill., is one of the earliest and most commonly used medicinal plants in Traditional Chinese Medicine (TCM) practice. We wanted to explore TCM for the identification of new chemical scaffolds with dual action abilities against HIV-1...
November 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Marc A Becker, Xiaonan Hou, Piyawan Tienchaianada, Brian B Haines, Sean C Harrington, S John Weroha, Sriram Sathyanarayanan, Paul Haluska
BACKGROUND: Mammalian target of rapamycin (mTOR) represents a key downstream intermediate for a myriad of oncogenic receptor tyrosine kinases. In the case of the insulin-like growth factor (IGF) pathway, the mTOR complex (mTORC1) mediates IGF-1 receptor (IGF-1R)-induced estrogen receptor alpha (ERα) phosphorylation/activation and leads to increased proliferation and growth in breast cancer cells. As a result, the prevalence of mTOR inhibitors combined with hormonal therapy has increased in recent years...
October 20, 2016: BMC Cancer
Pei Y Liu, Nicholas Sokolowski, Su T Guo, Faraz Siddiqi, Bernard Atmadibrata, Thomas J Telfer, Yuting Sun, Lihong Zhang, Denise Yu, Joshua Mccarroll, Bing Liu, Rui H Yang, Xiang Y Guo, Andrew E Tee, Ken Itoh, Jenny Wang, Maria Kavallaris, Michelle Haber, Murray D Norris, Belamy B Cheung, Jennifer A Byrne, David S Ziegler, Glenn M Marshall, Marcel E Dinger, Rachel Codd, Xu D Zhang, Tao Liu
BET bromodomain inhibitors are very promising novel anticancer agents, however, single therapy does not cause tumor regression in mice, suggesting the need for combination therapy. After screening a library of 2697 small molecule compounds, we found that two classes of compounds, the quinone-containing compounds such as nanaomycin and anti-microtubule drugs such as vincristine, exerted the best synergistic anticancer effects with the BET bromodomain inhibitor JQ1 in neuroblastoma cells. Mechanistically, the quinone-containing compound nanaomycin induced neuroblastoma cell death but also activated the Nrf2-antioxidant signaling pathway, and the BET bromodomain proteins BRD3 and BRD4 formed a protein complex with Nrf2...
October 13, 2016: Oncotarget
Meihui Chang, Xiaoyu Chu, Jinzhi Lv, Qingbin Li, Jian Tian, Ningfeng Wu
Pullulanase (EC plays an important role in the specific hydrolysis of branch points in amylopectin. Enhancing its thermostability is required for its industrial application. In this study, rational protein design was used to improve the thermostability of PulB from Bacillus naganoensis (AB231790.1), which has strong enzymatic properties. Three positive single-site mutants (PulB-D328H, PulB-N387D, and PulB-A414P) were selected from six mutants. After incubation at 65°C for 5 min, the residual activities of PulB-D328H, PulB-N387D, and PulB-A414P were 4...
2016: PloS One
N V Klementieva, K A Lukyanov, N M Markina, S A Lukyanov, E V Zagaynova, A S Mishin
Recently, an unusual phenomenon of primed conversion of fluorescent protein Dendra2 by combined action of blue (488 nm) and near-infrared (700-780 nm) lasers was discovered. Here we demonstrate that primed conversion can be induced by red lasers (630-650 nm) common for most confocal and single molecule detection microscopes.
October 20, 2016: Chemical Communications: Chem Comm
Jinglin Fu, Yuhe Renee Yang, Soma Dhakal, Zhao Zhao, Minghui Liu, Ting Zhang, Nils G Walter, Hao Yan
In nature, the catalytic efficiency of multienzyme complexes highly depends on their spatial organization. The positions and orientations of the composite enzymes are often precisely controlled to facilitate substrate transport between them. Self-assembled DNA nanostructures hold great promise for organizing biomolecules at the nanoscale. Here, we present detailed protocols for exploiting DNA nanostructures as assembly scaffolds that organize the spatial arrangements of multienzyme cascades with control over their relative distance, compartmentalization and substrate diffusion paths...
November 2016: Nature Protocols
Debojit Bhattacharya, Suranjan Shil, Anirban Misra, Laimutis Bytautas, Douglas J Klein
Here we study a set of novel magnetic organic molecular species with different halide ions (fluoride, chloride, bromide) absorbed ~2Å above or below the center of an aromatic π-ring in an m-aminyl diradical. Focus is on the nature of anion-π interaction and its impact on magnetic properties, specifically on magnetic anisotropy and on intramolecular magnetic exchange coupling. In the development of single molecule magnets, magnetic anisotropy is considered to be the most influential factor. A new insight regarding the magnetic anisotropy which determines the barrier height for relaxation of magnetization of m-aminyl diradical-derived anionic complexes is obtained from calculations of the axial Zero-Field-Splitting (ZFS) parameter D...
October 20, 2016: Journal of Physical Chemistry. A
Chao-Chen Lin, Hsin-Fang Hsu, Peter Jomo Walla
The fusion of two opposing membranes is essential in biological functions such as fertilization, viral entry, membrane trafficking and synaptic transmission. Before the membrane bilayers are fully connected, at some stage a hemifusion intermediate-when the outer leaflets are merged but not the inner leaflets-is formed. However, the position of hemifusion in the energy landscape and the duration of it vary and have not been fully mapped out. To date, there has not been a way to differentiate lipid mixing of the two leaflets directly in a single experiment...
October 20, 2016: Journal of Physical Chemistry. B
Hye-Hyeon Byeon, Seung-Woo Lee, Eun-Hee Lee, Woong Kim, Hyunjung Yi
Delicately assembled composites of semiconducting nanomaterials and biological materials provide an attractive interface for emerging applications, such as chemical/biological sensors, wearable health monitoring devices, and therapeutic agent releasing devices. The nanostructure of composites as a channel and a sensing material plays a critical role in the performance of field effect transistors (FETs). Therefore, it is highly desirable to prepare elaborate composite that can allow the fabrication of high performance FETs and also provide high sensitivity and selectivity in detecting specific chemical/biological targets...
October 20, 2016: Scientific Reports
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"