keyword
MENU ▼
Read by QxMD icon Read
search

fibril structure

keyword
https://www.readbyqxmd.com/read/28338788/hypertension-and-atrial-fibrillation-an-intimate-association-of-epidemiology-pathophysiology-and-outcomes
#1
Mikhail S Dzeshka, Farhan Shahid, Alena Shantsila, Gregory Y H Lip
Atrial fibrillation (AF) is the most prevalent sustained arrhythmia found in clinical practice. AF rarely exists as a single entity but rather as part of a diverse clinical spectrum of cardiovascular diseases, related to structural and electrical remodeling within the left atrium, leading to AF onset, perpetuation, and progression. Due to the high overall prevalence within the AF population arterial hypertension plays a significant role in the pathogenesis of AF and its complications. Fibroblast proliferation, apoptosis of cardiomyocytes, gap junction remodeling, accumulation of collagen both in atrial and ventricular myocardium all accompany ageing-related structural remodeling with impact on electrical activity...
February 18, 2017: American Journal of Hypertension
https://www.readbyqxmd.com/read/28338000/cavity-filling-mutations-at-the-thyroxine-binding-site-dramatically-increase-transthyretin-stability-and-prevent-its-aggregation
#2
Ricardo Sant'Anna, Maria Rosário Almeida, Nathalia Varejāo, Pablo Gallego, Sebastian Esperante, Priscila Ferreira, Alda Pereira-Henriques, Fernando L Palhano, Mamede de Carvalho, Debora Foguel, David Reverter, Maria João Saraiva, Salvador Ventura
More than a hundred different Transthyretin (TTR) mutations are associated with fatal systemic amyloidoses. They destabilize the protein tetrameric structure and promote the extracellular deposition of TTR as pathological amyloid fibrils. So far, only mutations R104H and T119M have been shown to stabilize significantly TTR, acting as disease suppressors. We describe a novel A108V non-pathogenic mutation found in a Portuguese subject. This variant is more stable than wild type TTR both in vitro and in human plasma, a feature that prevents its aggregation...
March 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28331489/reversible-atrial-fibrillation-following-crotalinae-envenomation
#3
Dan Quan, Kenneth Zurcher
BACKGROUND: Cardiotoxicity is a documented complication of Crotalinae envenomation. Reported cardiac complications following snake envenomation have included acute myocardial infarction, electrocardiogram abnormalities and arrhythmias. Few reports exist describing arrhythmia induced by viper envenomation and to our knowledge none describe arrhythmia induced by Crotalinae envenomation. This report concerns the first known case of atrial fibrillation precipitated by rattlesnake bite. CASE PRESENTATION: A 73-year-old Caucasian man with a past medical history of hypertension, hyperlipidemia, type 1 diabetes mellitus, and a baseline first-degree atrioventricular block presented to the emergency department following a rattlesnake bite to his left lower leg...
2017: Journal of Venomous Animals and Toxins Including Tropical Diseases
https://www.readbyqxmd.com/read/28331187/cross-beta-nanostructures-based-on-dinaphthylalanine-gd-conjugates-loaded-with-doxorubicin
#4
Carlo Diaferia, Eliana Gianolio, Teresa Sibillano, Flavia Anna Mercurio, Marilisa Leone, Cinzia Giannini, Nicole Balasco, Luigi Vitagliano, Giancarlo Morelli, Antonella Accardo
Very recently we proposed novel di- and tetra-phenylalanine peptides derivatized with gadolinium complexes as potentials supramolecular diagnostic agents for applications in MRI (Magnetic Resonance Imaging). It was observed that in very short FF dipeptide building blocks, the propensity to aggregate decreases significantly after modification with bulky moiety such as Gd-complexes, thus limiting their potential as CAs. We hypothesized that the replacement of the Phe side chain with more extended aromatic groups could improve the self-assembling...
March 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28330994/combining-dnp-nmr-with-segmental-and-specific-labeling-to-study-a-yeast-prion-protein-strain-that-is-not-parallel-in-register
#5
Kendra K Frederick, Vladimir K Michaelis, Marc A Caporini, Loren B Andreas, Galia T Debelouchina, Robert G Griffin, Susan Lindquist
The yeast prion protein Sup35NM is a self-propagating amyloid. Despite intense study, there is no consensus on the organization of monomers within Sup35NM fibrils. Some studies point to a β-helical arrangement, whereas others suggest a parallel in-register organization. Intermolecular contacts are often determined by experiments that probe long-range heteronuclear contacts for fibrils templated from a 1:1 mixture of (13)C- and (15)N-labeled monomers. However, for Sup35NM, like many large proteins, chemical shift degeneracy limits the usefulness of this approach...
March 22, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28330770/dj-1-a-parkinson-s-disease-related-protein-aggregates-under-denaturing-conditions-and-co-aggregates-with-%C3%AE-synuclein-through-hydrophobic-interaction
#6
Min Zhu, Shivaliben H Patel, Shubo Han
BACKGROUND: DJ-1, a small ubiquitously expressed protein implicated in several pathways associated with Parkinson's disease pathogenesis, has been found to interact with α-synuclein and modulate its aggregation, yet the exact mechanisms remain unclear. METHODS: The stability and aggregation properties of wild-type DJ-1 under denaturing conditions, such as low pH, high temperature, presence of denaturants were investigated. The interaction between DJ-1 and α-synuclein was tested by SDS-PAGE gel and native gel electrophoresis and by size-exclusion HPLC...
March 18, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28330339/the-attachment-of-%C3%AE-synuclein-to-a-fiber-a-coarse-grain-approach
#7
Ioana M Ilie, Wouter K den Otter, Wim J Briels
We present simulations of the amyloidogenic core of α-synuclein, the protein causing Parkinson's disease, as a short chain of coarse-grain patchy particles. Each particle represents a sequence of about a dozen amino acids. The fluctuating secondary structure of this intrinsically disordered protein is modelled by dynamic variations of the shape and interaction characteristics of the patchy particles, ranging from spherical with weak isotropic attractions for the disordered state to spherocylindrical with strong directional interactions for a β-sheet...
March 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28329137/association-of-left-atrial-structure-and-function-and-incident-cardiovascular-disease-in-patients-with-diabetes-mellitus-results-from-multi-ethnic-study-of-atherosclerosis-mesa
#8
Timothy M Markman, Mohammadali Habibi, Bharath Ambale Venketash, Mytra Zareian, Colin Wu, Susan R Heckbert, David A Bluemke, Joao A C Lima
Aims: Diabetes mellitus (DM) is associated with the development of cardiovascular disease (CVD). Morphological changes in the left atrium (LA) may appear before symptoms. We aimed to investigate the association between cardiac magnetic resonance imaging (CMR) measured LA structure and function and incident CVD in asymptomatic individuals with DM. Methods and results: Tissue tracking CMR was used to measure LA size and phasic function (emptying fractions and strain) on all 536 Multi-Ethnic Study of Atherosclerosis (MESA) participants with DM and available CMR at baseline in 2000-2002...
February 28, 2017: European Heart Journal Cardiovascular Imaging
https://www.readbyqxmd.com/read/28329017/navigating-in-foldonia-using-accelerated-molecular-dynamics-to-explore-stability-unfolding-and-self-healing-of-the-%C3%AE-solenoid-structure-formed-by-a-silk-like-polypeptide
#9
Binwu Zhao, Martien A Cohen Stuart, Carol K Hall
The β roll molecules with sequence (GAGAGAGQ)10 stack via hydrogen bonding to form fibrils which have been themselves been used to make viral capsids of DNA strands, supramolecular nanotapes and pH-responsive gels. Accelerated molecular dynamics (aMD) simulations are used to investigate the unfolding of a stack of two β roll molecules, (GAGAGAGQ)10, to shed light on the folding mechanism by which silk-inspired polypeptides form fibrils and to identify the dominant forces that keep the silk-inspired polypeptide in a β roll configuration...
March 22, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28328539/polarization-sensitive-localization-based-super-resolution-microscopy-with-a-birefringent-wedge
#10
József Sinkó, Tamás Gajdos, Elvira Czvik, Gábor Szabó, Miklós Erdélyi
A practical method has been presented for polarization sensitive localization based super-resolution microscopy using a birefringent dual wedge. The measurement of the polarization degree at the single molecule level can reveal the chemical and physical properties of the local environment of the fluorescent dye molecule and can hence provide information about the sub-diffraction sized structure of biological samples. Polarization sensitive STORM imaging of the F-Actins proved correlation between the orientation of fluorescent dipoles and the axis of the fibril...
March 22, 2017: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/28328228/reversible-morphological-control-of-cholecystokinin-tetrapeptide-amyloid-assemblies-as-a-function-of-ph
#11
Frédéric Gobeaux, Florence Porcher, Rajeev Dattani
Most amyloid assemblies are seen as irreversible and exhibit polymorphism because their assembly is kinetically controlled and different structures are trapped during the aggregation process. However, in the specific case of peptide hormones, formation of amyloid assemblies for storage purposes has been reported. This suggests a strict control of assembly and the ability to disassemble upon hormone secretion. In the present work, we have sought to test these assertions with a short peptide, the cholecystokinin (or gastrin) tetrapeptide (CCK-4), that has been found in both gastrointestinal tract and central nervous system, and whose sequence is shared by a large number of hormones...
March 22, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28327552/probing-medin-monomer-structure-and-its-amyloid-nucleation-using-13-c-direct-detection-nmr-in-combination-with-structural-bioinformatics
#12
Hannah A Davies, Daniel J Rigden, Marie M Phelan, Jillian Madine
Aortic medial amyloid is the most prevalent amyloid found to date, but remarkably little is known about it. It is characterised by aberrant deposition of a 5.4 kDa protein called medin within the medial layer of large arteries. Here we employ a combined approach of ab initio protein modelling and (13)C-direct detection NMR to generate a model for soluble monomeric medin comprising a stable core of three β-strands and shorter more labile strands at the termini. Molecular dynamics simulations suggested that detachment of the short, C-terminal β-strand from the soluble fold exposes key amyloidogenic regions as a potential site of nucleation enabling dimerisation and subsequent fibril formation...
March 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28324692/influence-of-graphene-oxide-and-reduced-graphene-oxide-on-the-activity-and-conformation-of-lysozyme
#13
Yitong Bai, Zhu Ming, Yuye Cao, Shicheng Feng, Hua Yang, Lingyun Chen, Sheng-Tao Yang
The dramatically different bio-effects of graphene and graphene oxide (GO) have been widely observed in diverse biological systems, which determine the applications and toxicity of graphene materials. To elucidate the mechanism at molecular level, it is urgent to investigate the enzyme-graphene interaction and its consequences. In this study, we comparatively studied the influence of GO and reduced GO (RGO) on the activity and conformation of lysozyme to provide better understandings of their different bio-effects...
March 8, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28322951/initiating-fibro-proliferation-through-interfacial-interactions-of-myoglobin-colloids-with-collagen-in-solution
#14
Madhumitha Dhanasekaran, Aruna Dhathathreyan
This work examines fibro-proliferation through interaction of myoglobin (Mb), a globular protein with collagen, an extracellular matrix fibrous protein. Designed colloids of Mb at pH 4.5 and 7.5 have been mixed with collagen solution at pH 7.5 and 4.5 in different concentrations altering their surface charges. For the Mb colloids, 100-200nm sizes have been measured from Transmission electron micrographs and zeta sizer. CD spectra shows a shift to beta sheet like structure for the protein in the colloids. Interaction at Mb/Collagen interface studied using Dilational rheology, Quartz crystal microbalance with dissipation and Differential Scanning calorimetry show that the perturbation is not only by the charge compensation arising from the difference in pH of the colloids and collagen, but also by the organized assembly of collagen at that particular pH...
March 18, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28322794/involvement-of-vimentin-in-neurite-outgrowth-damage-induced-by-fipronil-in-sh-sy5y-cells
#15
Theetat Ruangjaroon, Daranee Chokchaichamnankit, Chantragan Srisomsap, Jisnuson Svasti, N Monique Paricharttanakul
Fipronil, a phenylpyrazole insecticide, is more selective in its potency towards insects than humans and is thus commonly used. In this study, we demonstrated that exposure to fipronil may pose a human health risk. We observed in vitro the shortening of neurite outgrowths of SH-SY5Y neuroblastoma cells upon treatment with fipronil, even at a non-cytotoxic concentration. Fipronil induced apoptosis involving caspase-6, which is an apoptotic effector highly implicated in neurodegenerative diseases. Moreover, at a concentration that did not induce apoptosis, mitochondrial dysfunction and autophagic vacuole formation were detected...
March 17, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28320744/angiotensin-converting-enzyme-inhibitors-and-angiotensin-ii-receptor-blockers-are-associated-with-improved-outcome-but-do-not-prevent-new-onset-atrial-fibrillation-after-acute-myocardial-infarction
#16
Gorav Batra, Lars Lindhagen, Pontus Andell, David Erlinge, Stefan James, Jonas Spaak, Jonas Oldgren
BACKGROUND: Treatment with renin-angiotensin system (RAS) inhibitors might restrain the structural/electrical remodeling associated with atrial fibrillation (AF). Limited evidence exists regarding the potential benefits of RAS inhibition post-acute myocardial infarction (AMI) in patients with AF. This study sought to assess the association between RAS inhibition and all-cause mortality and new-onset AF in patients with/without congestive heart failure (CHF) post-AMI. METHODS AND RESULTS: Patients hospitalized for AMI between 2006 and 2012 were identified in Swedish registries...
March 20, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28319116/quenched-hydrogen-deuterium-exchange-nmr-of-a-disease-relevant-a%C3%AE-1-42-amyloid-polymorph
#17
Marielle Aulikki Wälti, Julien Orts, Roland Riek
Alzheimer's disease is associated with the aggregation into amyloid fibrils of Aβ(1-42) and Aβ(1-40) peptides. Interestingly, these fibrils often do not obtain one single structure but rather show different morphologies, so-called polymorphs. Here, we compare quenched hydrogen-deuterium (H/D) exchange of a disease-relevant Aβ(1-42) fibril for which the 3D structure has been determined by solid-state NMR with H/D exchange previously determined on another structural polymorph. This comparison reveals secondary structural differences between the two polymorphs suggesting that the two polymorphisms can be classified as segmental polymorphs...
2017: PloS One
https://www.readbyqxmd.com/read/28316992/a-combined-random-forests-and-active-contour-model-approach-for-fully-automatic-segmentation-of-the-left-atrium-in-volumetric-mri
#18
Chao Ma, Gongning Luo, Kuanquan Wang
Segmentation of the left atrium (LA) from cardiac magnetic resonance imaging (MRI) datasets is of great importance for image guided atrial fibrillation ablation, LA fibrosis quantification, and cardiac biophysical modelling. However, automated LA segmentation from cardiac MRI is challenging due to limited image resolution, considerable variability in anatomical structures across subjects, and dynamic motion of the heart. In this work, we propose a combined random forests (RFs) and active contour model (ACM) approach for fully automatic segmentation of the LA from cardiac volumetric MRI...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28316148/ablation-of-complex-fractionated-electrograms-with-or-without-additional-linear-lesions-for-persistent-atrial-fibrillation-the-adline-trial
#19
Sonia Ammar-Busch, Felix Bourier, Tilko Reents, Verena Semmler, Marta Telishevska, Susanne Kathan, Monika Hofmann, Gabriele Hessling, Isabel Deisenhofer
BACKGROUND: For persistent atrial fibrillation (AF) ablation, different strategies including complex fractionated atrial electrograms (CFAE) ablation and linear lesions (LL) have been used in addition to pulmonary vein isolation (PVI). However, it is still a matter of debate if extended substrate modification improves long-term outcome. The aim of this study was to determine the benefit of LL in addition to PVI and CFAE ablation regarding freedom from arrhythmia recurrence in patients with persistent AF...
March 18, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28315735/very-rapid-amyloid-fibril-formation-by-a-bacterial-lipase-in-the-absence-of-a-detectable-lag-phase
#20
Fatemeh Rashno, Khosro Khajeh, Claudia Capitini, Reza H Sajedi, Maryam Monsef Shokri, Fabrizio Chiti
The conversion of proteins from their soluble states into well-organized amyloid fibrils has received abundant attention. This process typically consists of three stages: lag, growth and plateau phases. In this study, the process of amyloid fibril formation by lipase from Pseudomonas sp. after diluting out urea was examined by Thioflavin T (ThT) fluorescence, Congo red (CR) binding, 8-anilinonaphthalene-1-sulfonic acid (ANS) binding, dynamic light scattering (DLS), circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopies, X-ray diffraction (XRD) and transmission electron microscopy (TEM)...
March 15, 2017: Biochimica et Biophysica Acta
keyword
keyword
110010
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"