Search results for "assembly"
showing 10 items of 768 documents
Hepatitis B virus maturation is sensitive to functional inhibition of ESCRT-III, Vps4, and gamma 2-adaptin.
2007
ABSTRACT Hepatitis B virus (HBV) is an enveloped DNA virus that presumably buds at intracellular membranes of infected cells. HBV budding involves two endocytic host proteins, the ubiquitin-interacting adaptor γ2-adaptin and the Nedd4 ubiquitin ligase. Here, we demonstrate that HBV release also requires the cellular machinery that generates internal vesicles of multivesicular bodies (MVBs). In order to perturb the MVB machinery in HBV-replicating liver cells, we used ectopic expression of dominant-negative mutants of different MVB components, like the ESCRT-III complex-forming CHMP proteins and the Vps4 ATPases. Upon coexpression of mutated CHMP3, CHMP4B, or CHMP4C forms, as well as of ATPa…
Exploring the Interplay Between Ligand Derivatisation and Cation Type in the Assembly of Hybrid Polyoxometalate Mn-Andersons
2012
Herein a library of hybrid Mn-Anderson polyoxometalates anions are presented: 1, [(MnMo6 O18 )((OCH2 )3 -C-(CH2 )7 CHCH2 )2 ](3-) ; compound 2, [(MnMo6 O18 )((OCH2 )3 C-NHCH2 C16 H9 )2 ](3-) ; compound 3, [(MnMo6 O18 )((OCH2 )3 C-(CH2 )7 CHCH2 )1 ((OCH2 )3 C-NHCH2 C16 H9 )1 ](3-) ; compound 4, [(MnMo6 O18 )((OCH2 )3 C-NHC(O)CH2 CHCH2 )2 ](3-) and compounds 5-9, [(MnMo6 O18 )((OCH2 )3 C-NHC(O)(CH2 )x CH3 )2 ]), where x = 4, 10, 12, 14, and 18 respectively. The compounds resulting from the cation exchange of the anions 1-9 to give TBA (a) and DMDOA (b) salts, and additionally for compounds 1, 2 and 3, tetraphenylphosphonium (PPh4 ) (c) salts, are explored at the air/water interface using scan…
Nano composite membrane-electrode assembly formation for fuel cell-modeling aspects
2007
Long term stability is an essential requirement for fuel cell applications in automobile and stationary energy systems. In these systems the agglomeration of the catalyst nanoparticles is a well-known phenomenon which cannot be easily overcome or compensated for by re-designing the system. A direct result of this occurrence is the irreversible decrease of the electrochemical performance. Irregularities in electric field distribution are one root cause for migration and subsequent agglomeration of the catalyst nanoparticle. In this work, the impact of the electrode mechanical deformation on electric field distribution was studied using a computer modeling approach. Model of a Proton Exchange…
Raman Spectroscopic Signatures of Echovirus 1 Uncoating
2014
ABSTRACT In recent decades, Raman spectroscopy has entered the biological and medical fields. It enables nondestructive analysis of structural details at the molecular level and has been used to study viruses and their constituents. Here, we used Raman spectroscopy to study echovirus 1 (EV1), a small, nonenveloped human pathogen, in two different uncoating states induced by heat treatments. Raman signals of capsid proteins and RNA genome were observed from the intact virus, the uncoating intermediate, and disrupted virions. Transmission electron microscopy data revealed general structural changes between the studied particles. Compared to spectral characteristics of proteins in the intact v…
Folding induced supramolecular assembly into pH-responsive nanorods with a protein repellent shell
2018
We report the synthesis of ABA' triblock peptide-polysarcosine-peptide conjugates featuring two complementary phenylalanine-histidine pentapeptide strands A/A'. These sequences encode for antiparallel beta-sheet formation into folded conjugates, which promote the self-assembly into polysarcosine-shielded core-shell nanorods. These do not cause aggregation of serum proteins in human blood plasma underlining an enhanced stability.
Parallelized short read assembly of large genomes using de Bruijn graphs
2011
Abstract Background Next-generation sequencing technologies have given rise to the explosive increase in DNA sequencing throughput, and have promoted the recent development of de novo short read assemblers. However, existing assemblers require high execution times and a large amount of compute resources to assemble large genomes from quantities of short reads. Results We present PASHA, a parallelized short read assembler using de Bruijn graphs, which takes advantage of hybrid computing architectures consisting of both shared-memory multi-core CPUs and distributed-memory compute clusters to gain efficiency and scalability. Evaluation using three small-scale real paired-end datasets shows tha…
Kinetically Trapped Supramolecular Assembly of Perylene Dianhydride Derivative in Methanol: Optical Spectra, Morphology, and Mechanisms.
2016
Supramolecular self-assembly has attracted increasing attention as a breakthrough methodology in the fields of nanoscience and nanotechnology. Herein, a perylene dianhydride derivative (TP-PDA) self-assembles into well-defined nanospheres through a nucleation-growth process. The mechanisms of this process were explored by using spectral analysis, dynamic light scattering (DLS), and scanning electron microscopy (SEM). In situ DLS and in situ SEM both revealed that the size of the aggregated nanospheres increases with time until the formation of equilibrium H-aggregates. This shows that TP-PDA undergoes a kinetically trapped assembly with a rapid transformation into the thermodynamically favo…
The key role of hydrogen bonding in the nuclearity of three copper(II) complexes with hydrazone-derived ligands and nitrogen donor heterocycles
2011
International audience; Three new Cu(II) complexes of formula [Cu(L1)(pyz)(CH3OH)]ClO4 (1), [Cu(L1)(4,4′-bpy)(ClO4)]·0.5H2O (2) and [{Cu(L2)(ClO4)}2(μ-4,4′-bpy)] (3) have been synthesised by using pyrazine (pyz) and 4,4′-bipyridine (4,4′-bpy) and tridentate O,N,O-donor hydrazone ligands, L1H and L2H, obtained by the condensation of 1,1,1-trifluoro-2,4-pentanedione with salicyloylhydrazide and benzhydrazide, respectively. The ligands and their complexes have been characterized by elemental analyses, FT-IR, and UV–Vis spectroscopies. Single crystal X-ray structure analysis evidences the metal ion in a slightly deformed square pyramidal geometry in all the complexes. However complexes 1 and 2 …
Reversible Supracolloidal Self-Assembly of Cobalt Nanoparticles to Hollow Capsids and Their Superstructures
2017
| openaire: EC/FP7/291364/EU//MIMEFUN The synthesis and spontaneous, reversible supracolloidal hydrogen bond-driven self-assembly of cobalt nanoparticles (CoNPs) into hollow shell-like capsids and their directed assembly to higher order superstructures is presented. CoNPs and capsids form in one step upon mixing dicobalt octacarbonyl (Co2CO8) and p-aminobenzoic acid (pABA) in 1,2-dichlorobenzene using heating-up synthesis without additional catalysts or stabilizers. This leads to pABA capped CoNPs (core ca. 5nm) with a narrow size distribution. They spontaneously assemble into tunable spherical capsids (d≈50-200nm) with a few-layered shells, as driven by inter-nanoparticle hydrogen bonds th…
Exploring the 2,2′-Diamino-5,5′-bipyrimidine Hydrogen-Bonding Motif: A Modular Approach to Alkoxy-Functionalized Hydrogen-Bonded Networks
1998
The programmed self-association of 2,2’-diamino-4,4’-dialkoxy-5,5’-bipyrimidines allows for the de novo construction of alkoxy-functionalized H-bonded ribbons and sheets as evidenced by X-ray crystallographic analysis. The data provide insight into the interplay of the different structural and interactional features of the molecular components to the generation of the supramolecular assembly. Hydrophobicity of the didodecyl side chains of 4c leads to the dominance of the H-bonding factor, resulting in the formation of a fully interconnected array. These results define the utility of the of 2,2’-diamino-4,4’-dialkoxy-5,5’-bipyrimidines as a potential scaffold for the attachment of electro- o…