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https://www.readbyqxmd.com/read/28102964/plasmonic-chirality-imprinting-on-nucleobase-displaying-supramolecular-nanohelices-by-metal-nucleobase-recognition
#1
Yiyang Lin, E Thomas Pashuck, Michael R Thomas, Nadav Amdursky, Shih-Ting Wang, Lesley W Chow, Molly M Stevens
Supramolecular self-assembly is an important process that enables the conception of complex structures mimicking biological motifs. Herein, we constructed helical fibrils through chiral self-assembly of nucleobase-peptide conjugates (NPCs), where achiral nucleobases are helically displayed on the surface of fibrils, comparable to polymerized nucleic acids. Selective binding between DNA and the NPC fibrils was observed with fluorescence polarization. Taking advantage of metal-nucleobase recognition, we highlight the possibility of deposition/assembly of plasmonic nanoparticles onto the fibrillar constructs...
January 19, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28102321/the-chaperonin-cct-inhibits-assembly-of-%C3%AE-synuclein-amyloid-fibrils-by-a-specific-conformation-dependent-interaction
#2
Begoña Sot, Alejandra Rubio-Muñoz, Ahudrey Leal-Quintero, Javier Martínez-Sabando, Miguel Marcilla, Cintia Roodveldt, José M Valpuesta
The eukaryotic chaperonin CCT (chaperonin containing TCP-1) uses cavities built into its double-ring structure to encapsulate and to assist folding of a large subset of proteins. CCT can inhibit amyloid fibre assembly and toxicity of the polyQ extended mutant of huntingtin, the protein responsible for Huntington's disease. This raises the possibility that CCT modulates other amyloidopathies, a still-unaddressed question. We show here that CCT inhibits amyloid fibre assembly of α-synuclein A53T, one of the mutants responsible for Parkinson's disease...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28101870/fibrillar-collagens
#3
Jordi Bella, David J S Hulmes
Fibrillar collagens (types I, II, III, V, XI, XXIV and XXVII) constitute a sub-group within the collagen family (of which there are 28 types in humans) whose functions are to provide three-dimensional frameworks for tissues and organs. These networks confer mechanical strength as well as signalling and organizing functions through binding to cellular receptors and other components of the extracellular matrix (ECM). Here we describe the structure and assembly of fibrillar collagens, and their procollagen precursors, from the molecular to the tissue level...
2017: Sub-cellular Biochemistry
https://www.readbyqxmd.com/read/28098204/strain-specific-fibril-propagation-by-an-a%C3%AE-dodecamer
#4
Dexter N Dean, Pradipta K Das, Pratip Rana, Franklin Burg, Yona Levites, Sarah E Morgan, Preetam Ghosh, Vijayaraghavan Rangachari
Low molecular weight oligomers of amyloid-β (Aβ) have emerged as the primary toxic agents in the etiology of Alzheimer disease (AD). Polymorphism observed within the aggregation end products of fibrils are known to arise due to microstructural differences among the oligomers. Diversity in aggregate morphology correlates with the differences in AD, cementing the idea that conformational strains of oligomers could be significant in phenotypic outcomes. Therefore, it is imperative to determine the ability of strains to faithfully propagate their structure...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28097689/investigating-magnetic-susceptibility-of-human-knee-joint-at-7-tesla
#5
Hongjiang Wei, Russell Dibb, Kyle Decker, Nian Wang, Yuyao Zhang, Xiaopeng Zong, Weili Lin, Daniel B Nissman, Chunlei Liu
PURPOSE: To evaluate the magnetic susceptibility properties of different anatomical structures within the knee joint using quantitative susceptibility mapping (QSM). METHODS: A collagen tissue model was simulated and ex vivo animal cartilage experiments were conducted at 9.4 Tesla (T) to evaluate the B0 orientation-dependent magnetic susceptibility contrast observed in cartilage. Furthermore, nine volunteers (six healthy subjects without knee pain history and three patients with known knee injury, between 29 and 58 years old) were scanned using gradient-echo acquisitions on a high-field 7T MR scanner...
January 17, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28095484/experimental-diabetes-alters-the-morphology-and-nano-structure-of-the-achilles-tendon
#6
Rodrigo Ribeiro de Oliveira, Rômulo Medina de Mattos, Luciana Magalhães Rebelo, Fernanda Guimarães Meireles Ferreira, Fernanda Tovar-Moll, Luiz Eurico Nasciutti, Gerly Anne de Castro Brito
Although of several studies that associate chronic hyperglycemia with tendinopathy, the connection between morphometric changes as witnessed by magnetic resonance (MR) images, nanostructural changes, and inflammatory markers have not yet been fully established. Therefore, the present study has as a hypothesis that the Achilles tendons of rats with diabetes mellitus (DM) exhibit structural changes. The animals were randomly divided into two experimental groups: Control Group (n = 06) injected with a vehicle (sodium citrate buffer solution) and Diabetic Group (n = 06) consisting of rats submitted to intraperitoneal administration of streptozotocin...
2017: PloS One
https://www.readbyqxmd.com/read/28093363/alignment-of-collagen-fiber-in-knitted-silk-scaffold-for-functional-massive-rotator-cuff-repair
#7
Zefeng Zheng, Jisheng Ran, Weishan Chen, Yejun Hu, Ting Zhu, Xiao Chen, Zi Yin, Boon Chin Heng, Gang Feng, Huihui Le, Chenqi Tang, Jiayun Huang, Yangwu Chen, Yiting Zhou, Pioletti Dominique, Weiliang Shen, Hong-Wei Ouyang
: Rotator cuff tear is one of the most common types of shoulder injuries, often resulting in pain and physical debilitation. Allogeneic tendon-derived decellularized matrices do not have appropriate pore size and porosity to facilitate cell infiltration, while commercially-available synthetic scaffolds are often inadequate at inducing tenogenic differentiation. The aim of this study is to develop an advanced 3D aligned collagen/silk scaffold (ACS) and investigate its efficacy in a rabbit massive rotator cuff tear model...
January 13, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28092777/controlling-the-3d-architecture-of-self-lifting-auto-generated-tissue-equivalents-slates-for-optimized-corneal-graft-composition-and-stability
#8
Ricardo M Gouveia, Elena González-Andrades, Juan C Cardona, Carmen González-Gallardo, Ana M Ionescu, Ingrid Garzon, Miguel Alaminos, Miguel González-Andrades, Che J Connon
Ideally, biomaterials designed to play specific physical and physiological roles in vivo should comprise components and microarchitectures analogous to those of the native tissues they intend to replace. For that, implantable biomaterials need to be carefully designed to have the correct structural and compositional properties, which consequently impart their bio-function. In this study, we showed that the control of such properties can be defined from the bottom-up, using smart surface templates to modulate the structure, composition, and bio-mechanics of human transplantable tissues...
December 23, 2016: Biomaterials
https://www.readbyqxmd.com/read/28080057/identification-of-binding-modes-for-amino-naphthalene-2-cyanoacrylate-anca-probes-to-amyloid-fibrils-from-molecular-dynamics-simulations
#9
Huan He, Juan Xu, Dan-Yang Cheng, Li Fu, Yu-Shu Ge, Feng-Lei Jiang, Yi Liu
Amino naphthalene 2-Cyanoacrylate (ANCA) probe is a kind of fluorescent amyloid binding probe that can report a different fluorescence emission when bound to different types of amyloid deposits in tissue, while their interactions with amyloid fibrils remain unclear due to the insoluble nature of amyloid fibrils. Here, all atom molecular dynamics simulations were used to investigate the interaction between ANCA probes with three different amyloid fibrils. Two common binding modes of ANCA probes on Aβ40 amyloid fibrils were identified by cluster analysis of multiple simulations...
January 12, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28077320/serine-threonine-phosphatases-in-atrial-fibrillation
#10
Jordi Heijman, Shokoufeh Ghezelbash, Xander H T Wehrens, Dobromir Dobrev
Serine/threonine protein phosphatases control dephosphorylation of numerous cardiac proteins, including a variety of ion channels and calcium-handling proteins, thereby providing precise post-translational regulation of cardiac electrophysiology and function. Accordingly, dysfunction of this regulation can contribute to the initiation, maintenance and progression of cardiac arrhythmias. Atrial fibrillation (AF) is the most common heart rhythm disorder and is characterized by electrical, autonomic, calcium-handling, contractile, and structural remodeling, which include, among other things, changes in the phosphorylation status of a wide range of proteins...
January 7, 2017: Journal of Molecular and Cellular Cardiology
https://www.readbyqxmd.com/read/28075583/amyloid-fibril-polymorphism-almost-identical-on-the-atomic-level-mesoscopically-very-different
#11
Carolin Seuring, Joeri Verasdonck, Philippe Ringler, Riccardo Cadalbert, Henning Stahlberg, Anja Böckmann, Beat H Meier, Roland Riek
Amyloid polymorphism of twisted and straight β-endorphin fibril was studied by negative-stain transmission electron microscopy, scanning transmission electron microscopy, and solid-state nuclear magnetic resonance spectroscopy. While fibrils assembled in the presence of salt form flat, striated ribbons, in the absence of salt they formed mainly twisted filaments. To get insights into their structural differences at the atomic level, 3D solid-state NMR spectra on both fibril types were acquired allowing the detection of the differences in chemical shifts of 13C and 15N atoms in both preparations...
January 11, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28075555/familial-mutations-may-switch-conformational-preferences-in-%C3%AE-synuclein-fibrils
#12
Liang Xu, Buyong Ma, Ruth Nussinov, Damien Thompson
The pathogenesis of Parkinson's disease is closely associated with the aggregation of the α-synuclein protein. Several familial mutants have been identified and shown to affect the aggregation kinetics of α-synuclein through distinct molecular mechanisms. Quantitative evaluation of the relative stabilities of the wild type and mutant fibrils is crucial for understanding the aggregation process and identifying the key component steps. In this work, we examined two topologically different α-synuclein fibril structures that are either determined by solid-state NMR method or modelled based on solid-state NMR data, and characterized their conformational properties and thermodynamic stabilities using molecular dynamics simulations...
January 11, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/28073885/reduction-of-atrial-fibrillation-burden-by-pulmonary-vein-isolation-leads-to-a-decrease-of-cd11b-expression-on-inflammatory-cells
#13
Daniel Tarnowski, Lina Plichta, Mathias Forkmann, Silvio Quick, Stefan Ulbrich, Felix Matthias Heidrich, Stephan Wiedemann, Marian Christoph, David Maximilian Poitz, Carsten Wunderlich, Karim Ibrahim, Ruth H Strasser, Christian Pfluecke
AIMS: It is hypothesized that inflammation could promote structural and electrical remodelling processes in atrial fibrillation (AF). Atrial infiltration of monocytes and granulocytes has been shown to be dependent on CD11b expression. The aim of this study was to investigate whether treatment of AF by pulmonary vein isolation (PVI) may lead to reduced inflammation, as indicated by a decrease of CD11b expression on monocytes and granulocytes. METHODS AND RESULTS: Flow-cytometric quantification analysis and determination of systemic inflammatory markers of peripheral blood were performed in 75 patients undergoing PVI 1 day before and 6 months after PVI...
January 10, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28073806/functional-tricuspid-regurgitation-caused-by-chronic-atrial-fibrillation-a-real-time-3-dimensional-transesophageal-echocardiography-study
#14
Hiroto Utsunomiya, Yuji Itabashi, Hirotsugu Mihara, Javier Berdejo, Sayuki Kobayashi, Robert J Siegel, Takahiro Shiota
BACKGROUND: Functional tricuspid regurgitation (TR) with a structurally normal tricuspid valve (TV) may occur secondary to chronic atrial fibrillation (AF). However, the clinical and echocardiographic differences according to functional TR subtypes are unclear. Therefore, characterization of functional TR because of chronic AF (AF-TR) remains undetermined. METHODS AND RESULTS: To investigate the prevalence of AF-TR, 437 patients with moderate to severe TR underwent 3-dimensional (3D) transesophageal echocardiography...
January 2017: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28071890/peptide-conjugates-of-benzene-carboxylic-acids-as-agonists-and-antagonists-of-amylin-aggregation
#15
Ruel Z B Desamero, Adam A Profit, Jayson Del Rosario Vedad
Human islet amyloid polypeptide (hIAPP), also known as amylin, is a 37 residue peptide hormone that is stored and co-secreted with insulin. hIAPP plays a pivotal role in type 2 diabetes and is the major component of amyloid deposits found in the pancreas of patients afflicted with the disease. The self-assembly of hIAPP and the formation of amyloid is linked to the death of insulin producing -cells. Recent findings suggest soluble hIAPP oligomers are the cytotoxic species responsible for -cell loss whereas amyloid fibrils themselves may indeed be innocuous...
January 10, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28071842/tip-enhanced-raman-spectroscopy-to-distinguish-toxic-oligomers-from-a%C3%AE-1-42-fibrils-at-the-nanometer-scale
#16
Sébastien Bonhommeau, David Talaga, Julien Hunel, Christophe Cullin, Sophie Lecomte
For the first time, natural Aβ1-42 fibrils (WT) implicated in Alzheimer's disease, as well as two synthetic mutants forming less toxic amyloid fibrils (L34T) and highly toxic oligomers (oG37C), are chemically characterized at the scale of a single structure using tip-enhanced Raman spectroscopy (TERS). While the proportion of TERS features associated with amino acid residues is similar for the three peptides, a careful examination of amide I and amide III bands allows us to clearly distinguish WT and L34T fibers organized in parallel β-sheets from the small and more toxic oG37C oligomers organized in anti-parallel β-sheets...
January 10, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28071819/evidence-that-interfibrillar-load-transfer-in-tendon-is-supported-by-small-diameter-fibrils-and-not-extrafibrillar-tissue-components
#17
Spencer E Szczesny, Kristen L Fetchko, George R Dodge, Dawn M Elliott
Collagen fibrils in tendon are believed to be discontinuous and transfer tensile loads through shear forces generated during interfibrillar sliding. However, the structures that transmit these interfibrillar forces are unknown. Various extrafibrillar tissue components (e.g., glycosaminoglycans, collagens XII and XIV) have been suggested to transmit interfibrillar loads by bridging collagen fibrils. Alternatively, collagen fibrils may interact directly through physical fusions and interfibrillar branching. The objective of this study was to test whether extrafibrillar proteins are necessary to transmit load between collagen fibrils or if interfibrillar load transfer is accomplished directly by the fibrils themselves...
January 10, 2017: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
https://www.readbyqxmd.com/read/28071716/lytic-polysaccharide-monooxygenases-disrupt-the-cellulose-fibers-structure
#18
Ana Villares, Céline Moreau, Chloé Bennati-Granier, Sona Garajova, Loïc Foucat, Xavier Falourd, Bodo Saake, Jean-Guy Berrin, Bernard Cathala
Lytic polysaccharide monooxygenases (LPMOs) are a class of powerful oxidative enzymes that breakdown recalcitrant polysaccharides such as cellulose. Here we investigate the action of LPMOs on cellulose fibers. After enzymatic treatment and dispersion, LPMO-treated fibers show intense fibrillation. Cellulose structure modifications visualized at different scales indicate that LPMO creates nicking points that trigger the disintegration of the cellulose fibrillar structure with rupture of chains and release of elementary nanofibrils...
January 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28070081/structural-discrimination-between-a%C3%AE-1-40-and-a%C3%AE-1-42-peptides-in-films-with-vibrational-circular-dichroism-spectroscopy
#19
Toshinori Morisaku, Hiroharu Yui
The secondary structure of full-length Aβ(1-40) and Aβ(1-42) peptides in films has been investigated with IR and vibrational circular dichroism (VCD) spectroscopy. From IR spectra, it is shown that the prepared films of Aβ(1-40) and Aβ(1-42) mainly comprise the β-sheet conformation that is characteristic of aggregated and fibrous Aβ. In the VCD spectra, the Aβ(1-42) film shows an intense and sharp band with left-handed optical activity at around 1625 cm(-1), while the Aβ(1-40) film shows a weak and broad band with right-handed activity at around 1630 cm(-1)...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/28069516/disruption-of-collagen-apatite-alignment-impairs-bone-mechanical-function-in-osteoblastic-metastasis-induced-by-prostate-cancer
#20
Aiko Sekita, Aira Matsugaki, Takayoshi Nakano
Prostate cancer (PCa) frequently metastasizes to the bone, generally inducing osteoblastic alterations that increase bone brittleness. Although there is growing interest in the management of the physical capability of patients with bone metastasis, the mechanism underlying the impairment of bone mechanical function remains unclear. The alignment of both collagen fibrils and biological apatite (BAp) c-axis, together with bone mineral density, is one of the strongest contributors to bone mechanical function. In this study, we analyzed the bone microstructure of the mouse femurs with and without PCa cell inoculation...
January 6, 2017: Bone
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