scholarly journals Corn zein undergoes conformational changes to higher β-sheet content during its self-assembly in an increasingly hydrophilic solvent

2020 ◽  
Vol 157 ◽  
pp. 232-239 ◽  
Author(s):  
Daniel P. Erickson ◽  
Oguz K. Ozturk ◽  
Gordon Selling ◽  
Feng Chen ◽  
Osvaldo H. Campanella ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Self Assembly ◽  
Corn Zein ◽  
Hydrophilic Solvent ◽  
Β Sheet

scholarly journals Interfacial Crystallization and Supramolecular Self-Assembly of Spider Silk Inspired Protein at the Water-Air Interface

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4239
Author(s):  
Pezhman Mohammadi ◽  
Fabian Zemke ◽  
Wolfgang Wagermaier ◽  
Markus B. Linder
Keyword(s):  
Self Assembly ◽  
Spider Silk ◽  
Assembly Process ◽  
Protein Solution ◽  
Time Resolved ◽  
Macromolecular Assembly ◽  
X Ray Scattering ◽  
Air Interface ◽  
Fundamental Research ◽  
Β Sheet

Macromolecular assembly into complex morphologies and architectural shapes is an area of fundamental research and technological innovation. In this work, we investigate the self-assembly process of recombinantly produced protein inspired by spider silk (spidroin). To elucidate the first steps of the assembly process, we examined highly concentrated and viscous pendant droplets of this protein in air. We show how the protein self-assembles and crystallizes at the water–air interface into a relatively thick and highly elastic skin. Using time-resolved in situ synchrotron X-ray scattering measurements during the drying process, we showed that the skin evolved to contain a high β-sheet amount over time. We also found that β-sheet formation strongly depended on protein concentration and relative humidity. These had a strong influence not only on the amount, but also on the ordering of these structures during the β-sheet formation process. We also showed how the skin around pendant droplets can serve as a reservoir for attaining liquid–liquid phase separation and coacervation from the dilute protein solution. Essentially, this study shows a new assembly route which could be optimized for the synthesis of new materials from a dilute protein solution and determine the properties of the final products.

Atomistic Modeling of Peptide Aggregation and β-Sheet Structuring in Corn Zein for Viscoelasticity

2021 ◽  
Author(s):  
Daniel P. Erickson ◽  
Martha Dunbar ◽  
Elham Hamed ◽  
Oguz K. Ozturk ◽  
Osvaldo H. Campanella ◽  
...  
Keyword(s):  
Peptide Aggregation ◽  
Atomistic Modeling ◽  
Corn Zein ◽  
Β Sheet

ChemInform Abstract: Mechanisms and Principles of 1D Self-Assembly of Peptides into β-Sheet Tapes

ChemInform ◽  
2010 ◽  
Vol 41 (12) ◽  
Author(s):  
Robert P. W. Davies ◽  
Amalia Aggeli ◽  
Neville Boden ◽  
Tom C. B. McLeish ◽  
Irena A. Nyrkova ◽  
...  
Keyword(s):  
Self Assembly ◽  
Β Sheet

ChemInform Abstract: Self-Assembly of Amphipathic β-Sheet Peptides: Insights and Applications

ChemInform ◽  
2012 ◽  
Vol 43 (36) ◽  
pp. no-no
Author(s):  
Charles J. Bowerman ◽  
Bradley L. Nilsson
Keyword(s):  
Self Assembly ◽  
Β Sheet

scholarly journals Structural control of fibrin bioactivity by mechanical deformation

2020 ◽  
Author(s):  
Sachin Kumar ◽  
Yujen Wang ◽  
Manuel K. Rausch ◽  
Sapun H. Parekh
Keyword(s):  
Biological Activity ◽  
Conformational Changes ◽  
Structural Control ◽  
Structural Changes ◽  
Tensile Deformation ◽  
Mechanical Strain ◽  
Fibrous Protein ◽  
Binding Partners ◽  
Blood Clots ◽  
Β Sheet

AbstractFibrin is a fibrous protein network that entraps blood cells and platelets to form blood clots following vascular injury. As a biomaterial, fibrin acts a biochemical scaffold as well as a viscoelastic patch that resists mechanical insults. The biomechanics and biochemistry of fibrin have been well characterized independently, showing that fibrin is a hierarchical material with numerous binding partners. However, comparatively little is known about how fibrin biomechanics and biochemistry are coupled: how does fibrin deformation influence its biochemistry at the molecular level? In this study, we show how mechanically-induced molecular structural changes in fibrin affect fibrin biochemistry and fibrin-platelet interaction. We found that tensile deformation of fibrin lead to molecular structural transitions of α-helices to β-sheets, which reduced binding of tissue plasminogen activator (tPA), an enzyme that initiates fibrinolysis, at the network and single fiber level. Moreover, binding of tPA and Thioflavin T (ThT), a commonly used β-sheet marker, was primarily mutually exclusive such that tPA bound to native (helical) fibrin whereas ThT bound to strained fibrin. Finally, we demonstrate that conformational changes in fibrin suppressed the biological activity of platelets on mechanically strained fibrin due to attenuated αIIbβ3 integrin binding. Our work shows that mechanical strain regulates fibrin molecular structure and fibrin biological activity in an elegant mechano-chemical feedback loop, which likely influences fibrinolysis and wound healing kinetics.

scholarly journals Effect of the Hydrophilic-Hydrophobic Balance of Antigen-Loaded Peptide Nanofibers on Their Cellular Uptake, Cellular Toxicity, and Immune Stimulatory Properties

2019 ◽  
Vol 20 (15) ◽  
pp. 3781 ◽  
Author(s):  
Tomonori Waku ◽  
Saki Nishigaki ◽  
Yuichi Kitagawa ◽  
Sayaka Koeda ◽  
Kazufumi Kawabata ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
Self Assembly ◽  
Sheet Forming ◽  
Design Guidelines ◽  
Cellular Interactions ◽  
Antigenic Peptides ◽  
Peptide Nanofibers ◽  
Dc Line ◽  
Chain Lengths ◽  
Β Sheet

Recently, nanofibers (NFs) formed from antigenic peptides conjugated to β-sheet-forming peptides have attracted much attention as a new generation of vaccines. However, studies describing how the hydrophilic-hydrophobic balance of NF components affects cellular interactions of NFs are limited. In this report, three different NFs were prepared by self-assembly of β-sheet-forming peptides conjugated with model antigenic peptides (SIINFEKL) from ovalbumin and hydrophilic oligo-ethylene glycol (EG) of differing chain lengths (6-, 12- and 24-mer) to investigate the effect of EG length of antigen-loaded NFs on their cellular uptake, cytotoxicity, and dendritic cell (DC)-stimulation ability. We used an immortal DC line, termed JAWS II, derived from bone marrow-derived DCs of a C57BL/6 p53-knockout mouse. The uptake of NFs, consisting of the EG 12-mer by DCs, was the most effective and activated DC without exhibiting significant cytotoxicity. Increasing the EG chain length significantly reduced cellular entry and DC activation by NFs. Conversely, shortening the EG chain enhanced DC activation but increased toxicity and impaired water-dispersibility, resulting in low cellular uptake. These results show that the interaction of antigen-loaded NFs with cells can be tuned by the EG length, which provides useful design guidelines for the development of effective NF-based vaccines.

scholarly journals Dual self-assembly of supramolecular peptide nanotubes to provide stabilisation in water

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Julia Y. Rho ◽  
Henry Cox ◽  
Edward D. H. Mansfield ◽  
Sean H. Ellacott ◽  
Raoul Peltier ◽  
...  
Keyword(s):  
Self Assembly ◽  
Supramolecular Assembly ◽  
Ordered Structures ◽  
Peptide Bonds ◽  
Self Assembling ◽  
Peptide Hydrogen ◽  
Aqueous Conditions ◽  
Β Sheet ◽  
Peptide Core ◽  
Hydrogen Bonded

Abstract Self-assembling peptides have the ability to spontaneously aggregate into large ordered structures. The reversibility of the peptide hydrogen bonded supramolecular assembly make them tunable to a host of different applications, although it leaves them highly dynamic and prone to disassembly at the low concentration needed for biological applications. Here we demonstrate that a secondary hydrophobic interaction, near the peptide core, can stabilise the highly dynamic peptide bonds, without losing the vital solubility of the systems in aqueous conditions. This hierarchical self-assembly process can be used to stabilise a range of different β-sheet hydrogen bonded architectures.

scholarly journals Structural characterization of toxic oligomers that are kinetically trapped during α-synuclein fibril formation

2015 ◽  
Vol 112 (16) ◽  
pp. E1994-E2003 ◽  
Author(s):  
Serene W. Chen ◽  
Srdja Drakulic ◽  
Emma Deas ◽  
Myriam Ouberai ◽  
Francesco A. Aprile ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Self Assembly ◽  
Protein Misfolding ◽  
Amyloid Fibril ◽  
Amyloid Formation ◽  
Image Reconstruction Techniques ◽  
Cryo Electron Microscopy ◽  
Amyloid Oligomers ◽  
Β Sheet

We describe the isolation and detailed structural characterization of stable toxic oligomers of α-synuclein that have accumulated during the process of amyloid formation. Our approach has allowed us to identify distinct subgroups of oligomers and to probe their molecular architectures by using cryo-electron microscopy (cryoEM) image reconstruction techniques. Although the oligomers exist in a range of sizes, with different extents and nature of β-sheet content and exposed hydrophobicity, they all possess a hollow cylindrical architecture with similarities to certain types of amyloid fibril, suggesting that the accumulation of at least some forms of amyloid oligomers is likely to be a consequence of very slow rates of rearrangement of their β-sheet structures. Our findings reveal the inherent multiplicity of the process of protein misfolding and the key role the β-sheet geometry acquired in the early stages of the self-assembly process plays in dictating the kinetic stability and the pathological nature of individual oligomeric species.

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