Read by QxMD icon Read

fibril structure

Majid Jafari, Faramarz Mehrnejad
Changes in the tertiary structure of proteins and the resultant fibrillary aggregation could result in fatal heredity diseases, such as lysozyme systemic amyloidosis. Human lysozyme is a globular protein with antimicrobial properties with tendencies to fibrillate and hence is known as a fibril-forming protein. Therefore, its behavior under different ambient conditions is of great importance. In this study, we conducted two 500000 ps molecular dynamics (MD) simulations of human lysozyme in sodium dodecyl sulfate (SDS) at two ambient temperatures...
2016: PloS One
Natalia Eliza Domeradzka, Marc W T Werten, Frits A de Wolf, Renko de Vries
Previously, we developed triblock protein polymers that form fibrillar hydrogels at low protein polymer concentrations (denoted C2-SH48-C2). We here demonstrate that the structure of these hydrogels can be tuned via heterodimeric coiled coils that cross-link and bundle the self-assembled protein-polymer fibrils. We fused well-characterized, 47 amino acids-long heterodimeric coiled coil "linkers" (DA or DB) to the C-terminus of the triblock polymer. The resulting C2-SH48-C2-DA and C2-SH48-C2-DB polymers, were successfully produced as secreted proteins in Pichia pastoris, with titers of purified protein in the order of g L-1 of clarified broth...
October 21, 2016: Biomacromolecules
Natarajan Suganthy, Dicson Sheeja Malar, Kasi Pandima Devi
OBJECTIVE: Amyloid hypothesis states that endogenous β-amyloid peptides (Aβ), especially its aggregated oligomers and fibrils are the key pathogenic factors leading to Alzheimer's disease (AD). Therefore, inhibition of Aβ fibrillation rather than blocking its production is considered promising therapeutic intervention. Hence, the present study was carried out to assess the effect of methanolic leaf extract of R. mucronata (MERM) and its bioactive compound catechin on in vitro fibrillation of Aβ (25-35)...
October 21, 2016: Neurological Research
Kishan A Manani, Kim Christensen, Nicholas S Peters
Atrial fibrillation (AF) increases the risk of stroke by a factor of 4-5 and is the most common abnormal heart rhythm. The progression of AF with age, from short self-terminating episodes to persistence, varies between individuals and is poorly understood. An inability to understand and predict variation in AF progression has resulted in less patient-specific therapy. Likewise, it has been a challenge to relate the microstructural features of heart muscle tissue (myocardial architecture) with the emergent temporal clinical patterns of AF...
October 2016: Physical Review. E
Anna V Glyakina, Nikolai K Balabaev, Oxana V Galzitskaya
The amyloidogenic peptide VDSWNVLVAG from Bgl2p-glucantransferase of Saccharomyces cerevisiae cell wall and its modifying analog VESWNVLVAG were taken for the construction of four types of bilayers which differ by orientation of the peptides in the layers and of the layers relative to each other. These bilayers were used as starting models for the molecular dynamics (MD) at three charge states (neutral, pH3, and pH5). The changes of the fraction of secondary structure during 1 ns simulations were received for 96 MD trajectories...
December 2016: Data in Brief
Florian Hoss, Juan F Rodriguez-Alcazar, Eicke Latz
The inflammasome adapter ASC links activated inflammasome sensors to the effector molecule pro-caspase-1. Recruitment of pro-caspase-1 to ASC promotes the autocatalytic activation of caspase-1, which leads to the release of pro-inflammatory cytokines, such as IL-1β. Upon triggering of inflammasome sensors, ASC assembles into large helical fibrils that interact with each other serving as a supramolecular signaling platform termed the ASC speck. Alternative splicing, post-translational modifications of ASC, as well as interaction with other proteins can perturb ASC function...
October 19, 2016: Cellular and Molecular Life Sciences: CMLS
Shawn P Reese, Niloofar Farhang, Randy Poulson, Gennie Parkman, Jeffrey A Weiss
In vitro polymerized type I collagen hydrogels have been used extensively as a model system for three-dimensional (3D) cell and tissue culture, studies of fibrillogenesis, and investigation of multiscale force transmission within connective tissues. The nanoscale organization of collagen fibrils plays an essential role in the mechanics of these gels and emergent cellular behavior in culture, yet quantifying 3D structure with nanoscale resolution to fully characterize fibril organization remains a significant technical challenge...
October 18, 2016: Biophysical Journal
Qin Qiao, Ruxi Qi, Guanghong Wei, Xuhui Huang
Amyloid deposits of human islet amyloid polypeptide (hIAPP) are identified in 95% of type II diabetes patients. The oligomers during the early stage of hIAPP aggregation are believed to be more cytotoxic than the mature fibrils. However, the structural details during the initial stage of hIAPP aggregation are still under debate experimentally. To understand its initial nucleation mechanism, we investigate the thermodynamics and kinetics of hIAPP(11-25) dimerization, which is the first manifestation of the interplay between intra- and inter-molecular interactions, via the construction of Markov state models from extensive molecular dynamics simulations...
October 19, 2016: Physical Chemistry Chemical Physics: PCCP
Ying Wei, Jun Lu, Tong Lu, Feihong Meng, Jia Xu, Li Wang, Yang Li, Liping Wang, Fei Li
Prefibrillar amyloid aggregates of proteins are known as cytotoxic species and a common pathogenic factor for many degenerative diseases. The mechanism underlying the formation and cytotoxicity of prefibrillar aggregates is believed to be independent of the actual nature of the amyloid protein. In this study, we monitored the formation of the peptide oligomers and examined the disruptive effects of the oligomers on liposomes using the human islet amyloid polypeptide fragment hIAPP18-27 as a model peptide. We observed various morphologies of oligomers formed at different aggregation stages that precede the formation of mature amyloid fibrils...
October 19, 2016: Physical Chemistry Chemical Physics: PCCP
Nathan R Tucker, Saagar Mahida, Jiangchuan Ye, Elizabeth J Abraham, Julie A Mina, Victoria A Parsons, Michael A McLellan, Marisa A Shea, Alan Hanley, Emelia J Benjamin, David J Milan, Honghuang Lin, Patrick T Ellinor
BACKGROUND: The genetic basis of atrial fibrillation (AF) and congenital heart disease remains incompletely understood. OBJECTIVE: We sought to determine the causative mutation in a family with AF, atrial septal and ventricular septal defects. METHODS: We evaluated a pedigree with 16 family members, one with an atrial septal defect, one with a ventricular septal defect and three with AF; we performed whole exome sequencing in three affected family members...
October 15, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Koning Shen, Barbara Calamini, Jonathan A Fauerbach, Boxue Ma, Sarah H Shahmoradian, Ivana L Serrano Lachapel, Wah Chiu, Donald C Lo, Judith Frydman
Many neurodegenerative diseases are linked to amyloid aggregation. In Huntington's disease (HD), neurotoxicity correlates with increased aggregation propensity of a polyglutamine (polyQ) expansion in exon 1 of mutant huntingtin protein (mHtt). Here we establish how the domains flanking the polyQ tract shape the mHtt conformational landscape in vitro and in neurons. In vitro, the flanking domains have opposing effects on the conformation and stabilities of oligomers and amyloid fibrils. The N-terminal N17 promotes amyloid fibril formation, while the C-terminal Proline Rich Domain destabilizes fibrils and enhances oligomer formation...
October 18, 2016: ELife
Ximena Zottig, Mathieu Laporte Wolwertz, Makan Golizeh, Leanne Ohlund, Lekha Sleno, Steve Bourgault
Light chain amyloidosis (AL) originates from the deposition of immunoglobulin light chains (LCs) as amyloid fibrils in the extracellular space of vital organs. Although non-enzymatic post-translational modifications (PTMs) have been shown to contribute to protein misfolding diseases, little is known about their contributions to LC amyloidogenicity. In this study, we investigated the effects of three oxidative PTMs, carbonylation by hydroxynonenal (HNE), oxidation and nitration, on the structure, thermodynamic stability and self-assembly propensity of a LC variable domain from the λ6 germline, Wil...
October 11, 2016: Biophysical Chemistry
Tomos E Walters, Jonathan M Kalman, Sheila K Patel, Megan Mearns, Elena Velkoska, Louise M Burrell
AIM: Angiotensin converting enzyme 2 (ACE2) is an integral membrane protein whose main action is to degrade angiotensin II. Plasma ACE2 activity is increased in various cardiovascular diseases. We aimed to determine the relationship between plasma ACE2 activity and human atrial fibrillation (AF), and in particular its relationship to left atrial (LA) structural remodelling. METHODS AND RESULTS: One hundred and three participants from a tertiary arrhythmia centre, including 58 with paroxysmal AF (PAF), 20 with persistent AF (PersAF), and 25 controls, underwent clinical evaluation, echocardiographic analysis, and measurement of plasma ACE2 activity...
October 12, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Mamoru Haratake, Tohru Takiguchi, Naho Masuda, Sakura Yoshida, Takeshi Fuchigami, Morio Nakayama
Sup35 is a prion-like protein from yeast and shares the ability to transmit its aberrant fold and to aggregate into amyloid fibrils. (7)GNNQQNY(13) from the prion-determining domain of Sup35 was reported to form an amyloid. We first investigated the self-aggregation transition behavior of GNNQQNY to the β-sheet amyloid state under various conditions. Mechanical stirring using a magnetic bar resulted in accelerated aggregation of the GNNQQNY. The aggregation rate of GNNQQNY was also dependent on its concentration; the higher the GNNQQNY concentration, the faster the aggregation...
October 7, 2016: Colloids and Surfaces. B, Biointerfaces
Zhichao Xiao, Wenting Guo, Bo Sun, Donald J Hunt, Jinhong Wei, Yingjie Liu, Yundi Wang, Ruiwu Wang, Peter P Jones, Thomas G Back, S R Wayne Chen
Recent three-dimensional structural studies reveal that the Central domain of ryanodine receptor (RyR) serves as a transducer that converts long-range conformational changes into the gating of the channel pore. Interestingly, the Central domain encompasses one of the mutation hotspots (corresponding to amino acid residues 3778-4201) that contains a number of cardiac RyR (RyR2) mutations associated with catecholaminergic polymorphic ventricular tachycardia (CPVT) and atrial fibrillation (AF). However, the functional consequences of these Central domain RyR2 mutations are not well understood...
October 12, 2016: Journal of Biological Chemistry
Flemming Javier Olsen, Litten Bertelsen, Martina Chantal de Knegt, Thomas Emil Christensen, Niels Vejlstrup, Jesper Hastrup Svendsen, Jan Skov Jensen, Tor Biering-Sørensen
Several cardiac imaging modalities are able to visualize the left atrium (LA) and, therefore, allow for quantification of both structural and functional properties of this cardiac chamber. In echocardiography, only the maximal LA volume is included in the assessment of diastolic function at the current moment. Numerous studies, however, have shown that functional measures may be superior to the maximal LA volume in several aspects and to possess clinical value even in the absence of structural abnormalities...
October 2016: Circulation. Cardiovascular Imaging
Yang Song, Ulyana Shimanovich, Thomas C T Michaels, Qingming Ma, Jingmei Li, Tuomas P J Knowles, Ho Cheung Shum
All-aqueous emulsions exploit spontaneous liquid-liquid separation and due to their water-based nature are particular advantageous for the biocompatible storage and processing of biomacromolecules. However, the ultralow interfacial tensions characteristic of all-aqueous interfaces represent an inherent limitation to the use of thermally adsorbed particles to achieve emulsion stability. Here, we use protein nanofibrils to generate colloidosome-like two-dimensional crosslinked networks of nanostructures templated by all-aqueous emulsions, which we term fibrillosomes...
October 11, 2016: Nature Communications
Jose F Condado, Hanna A Jensen, Aneel Maini, Yi-An Ko, Mohammad H Rajaei, Lillian L Tsai, Chandan Devireddy, Bradley Leshnower, Kreton Mavromatis, Eric L Sarin, James Stewart, Robert A Guyton, Vasilis Babaliaros, Edward P Chen, Michael Halkos, Amy Simone, Patricia Keegan, Peter C Block, Vinod H Thourani
BACKGROUND: Screening for internal carotid artery stenosis (ICAS) with Doppler ultrasound is commonly used before cardiovascular surgery. Nevertheless, the relationship between ICAS and procedure-related stroke in isolated aortic valve replacement is unclear. METHODS: We retrospectively reviewed patients with artery stenosis who underwent ICAS screening before surgical (SAVR) or transcatheter aortic valve replacement (TAVR) between January 2007 and August 2014. Logistic regression models were used to determine the relation between post-procedure stroke and total (sum of left and right ICAS) and maximal unilateral ICAS...
October 4, 2016: Annals of Thoracic Surgery
Shunsuke Uetake, Mitsunori Maruyama, Teppei Yamamoto, Katsuhito Kato, Yasushi Miyauchi, Yoshihiko Seino, Wataru Shimizu
BACKGROUND: Left ventricular (LV) diastolic dysfunction depends on an impaired relaxation and stiffness. Abnormal LV relaxation contributes to the development of atrial fibrillation (AF), but the role of LV stiffness in AF remains unclear. HYPOTHESIS: Diastolic wall strain (DWS), a load-independent, noninvasive direct measure of LV stiffness, correlates with prevalent AF. METHODS: This study included 328 consecutive subjects with structurally normal hearts: 164 paroxysmal AF patients and 164 age- and sex-matched (1:1) controls...
October 7, 2016: Clinical Cardiology
Fabián Rueda, Brigitte Gasser, Alejandro Sánchez-Chardi, Mònica Roldán, Sandra Villegas, Verena Puxbaum, Neus Ferrer-Miralles, Ugutz Unzueta, Esther Vázquez, Elena Garcia-Fruitós, Diethard Mattanovich, Antonio Villaverde
BACKGROUND: Bacterial inclusion bodies (IBs) are non-toxic protein aggregates commonly produced in recombinant bacteria. They are formed by a mixture of highly stable amyloid-like fibrils and releasable protein species with a significant extent of secondary structure, and are often functional. As nano structured materials, they are gaining biomedical interest because of the combination of submicron size, mechanical stability and biological activity, together with their ability to interact with mammalian cell membranes for subsequent cell penetration in absence of toxicity...
October 1, 2016: Microbial Cell Factories
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"