A Comparative Study on the Self-Assembly of Peptide TGV-9 by In Situ Atomic Force Microscopy

2020 ◽  
Vol 26 (2) ◽  
pp. 319-325
Author(s):  
Yaping Li ◽  
Na Li ◽  
Lei Wang ◽  
Qinhua Lu ◽  
Xiang Ji ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Peptide Sequence ◽  
Bulk Solution ◽  
Free Standing ◽  
Atomic Lattice ◽  
Force Microscopy ◽  
Atomic Force

AbstractPrevious studies of amyloid diseases reported that the aggregating proteins share a similar conserved peptide sequence which can form the cross-β-sheet-containing nanostructures like nanofilaments. The template-assisted self-assembly (TASA) of peptides on inorganic substrates with different hydrophilicity could be an alternative approach to shed light on the fibrillization mechanism of proteins/peptides in vivo. To figure out the effect of interfaces on amyloid aggregation, we herein employed in situ atomic force microscopy (AFM) to investigate the self-assembling of a Parkinson disease-related core peptide sequence (TGV-9) on a hydrophobic liquid–solid interface via real-time observation of the dynamic fibrillization process. The results show that TGV-9 forms one-dimensional nanostructures on the surface of highly ordered pyrolytic graphite (HOPG) with three preferred growth orientations, which are consistent with the atomic lattice of HOPG, indicating an epitaxial growth or TASA. Conversely, the nanostructures formed in bulk solution can be free-standing nanofilaments, and the fibrillization mechanism is different from that on HOPG. These results could not only deepen the understanding of the protein/peptide aggregation mechanism but also benefit for the early diagnosis and clinic treatment of related diseases.

Chromic Polydiacetylene Single Crystals: Atomic Force Microscopy Studies

1995 ◽  
Vol 413 ◽  
Author(s):  
V. Shivshankar ◽  
C. Sung ◽  
J. Kumar ◽  
S. K. Tripathy ◽  
D. J. Sandman
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Single Crystals ◽  
Ambient Conditions ◽  
Free Standing ◽  
Force Microscopy ◽  
Sensor Performance ◽  
Atomic Force ◽  
Variable Surface

ABSTRACTWe have studied the surface morphology of free standing single crystals of thermochromic polydiacetylenes (PDAs), namely, ETCD and IPUDO (respectively, the ethyl and isopropyl urethanes of 5,7-dodecadiyn-1,12-diol), by Atomic Force Microscopy (AFM) under ambient conditions. Micron scale as well as molecularly resolved images were obtained. The micron scale images indicate a variable surface, and the molecularly resolved images show a well defined 2-D lattice that is interpreted in terms of molecular models and known crystallographic data. Thereby information about surface morphology, which is crucial to potential optical device or chromic sensor performance is available. We also report the observation of a “macroscopic shattering” of the IPUDO monomer crystal during in-situ UV polymerization studies.

NANOSTRUCTURES FROM DESIGNER PEPTIDES

COSMOS ◽  
2008 ◽  
Vol 04 (02) ◽  
pp. 173-183
Author(s):  
BOON TEE ONG ◽  
PARAYIL KUMARAN AJIKUMAR ◽  
SURESH VALIYAVEETTIL
Keyword(s):  
Atomic Force Microscopy ◽  
Solid State ◽  
Self Assembly ◽  
Size Range ◽  
The Self ◽  
Mica Surface ◽  
Force Microscopy ◽  
Solution Structures ◽  
Atomic Force

The present article reviews the self-assembly of oligopeptides to form nanostructures, both in solution and in solid state. The solution structures of the peptides were examined using circular dichroism and dynamic light scattering. The solid state assembly was examined by adsorbing the peptides onto a mica surface and analyzing it using atomic force microscopy. The role of pH and salt concentration on the peptide self-assembly was also examined. Nanostructures within a size range of 3–10 nm were obtained under different conditions.

scholarly journals Pathway Complexity in Supramolecular Porphyrin Self-Assembly at an Immiscible Liquid|Liquid Interface

2021 ◽  
Author(s):  
Iván Robayo-Molina ◽  
Andrés F. Molina-Osorio ◽  
Luke Guinane ◽  
Syed A.M. Tofail ◽  
Micheal D. Scanlon
Keyword(s):  
Self Assembly ◽  
Immiscible Liquid ◽  
Bulk Solution ◽  
Time Resolved ◽  
Force Microscopy ◽  
Atomic Force ◽  
Aggregate Growth ◽  
High Concentrations ◽  
Thermodynamic Processes

<p>Nanostructures that are inaccessible through spontaneous thermodynamic processes may be formed by supramolecular self-assembly under kinetic control. In the past decade, the dynamics of pathway complexity in self-assembly have been elucidated through kinetic models based on aggregate growth by sequential monomer association and dissociation. Immiscible liquid|liquid interfaces are an attractive platform to develop well-ordered self-assembled nanostructures, unattainable in bulk solution, due to the templating interaction of the interface with adsorbed molecules. Here, we report time-resolved <i>in situ</i> UV/vis spectroscopic observations of the self-assembly of zinc(II) meso-tetrakis(4-carboxyphenyl)porphyrin (ZnTPPc) at an immiscible aqueous|organic interface. We show that the kinetically favoured metastable J-type nanostructures form quickly, but then transform into stable thermodynamically favoured H-type nanostructures. Numerical modelling revealed two parallel and competing cooperative pathways leading to the different porphyrin nanostructures. These insights demonstrate that pathway complexity is not unique to self-assembly processes in bulk solution, and equally valid for interfacial self-assembly. Subsequently, the interfacial electrostatic environment was tuned using a kosmotropic anion (citrate) in order to control the influence the pathway selection. At high concentrations, interfacial nanostructure formation was forced completely down the kinetically favoured pathway and only J-type nanostructures were obtained. Furthermore, we found by atomic force microscopy (AFM) and scanning electron microscopy (SEM) that the J- and H-type nanostructures obtained at low and high citric acid concentrations, respectively, are morphologically distinct, which illustrates the pathway-dependent material properties.</p>

scholarly journals Cation-Specific Effects on the Self-Assembly of Collagen Molecules Mediated by Acetate on Mica Surface Observed with Atomic Force Microscopy

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhiwei Wang ◽  
Qi Xiao ◽  
Xuan Song ◽  
Yunfei Wan ◽  
Jie Zhu
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Ionic Concentration ◽  
Collagen Fibrils ◽  
The Self ◽  
Mica Surface ◽  
Force Microscopy ◽  
Specific Effects ◽  
Atomic Force ◽  
Base Method

The well-organized collagen layers on mica surface have drawn extensive attention for its essential applications and studies on the process of self-assembly as a model system. In this work, collagen extracted from fish scales by acid-base method was used to explore the self-assembly characters, and atomic force microscopy was applied to observe the collagen assembled on mica surface mediated by acetate with four different cations, including K+, Na+, Mg2+, and Ca2+. It showed that cations might influence the interaction between collagen fibrils and mica surface at high ionic concentration. And a similar network structure was acquired with uniform pore size for four kinds of acetates; nearly ranged collagen fibrils in the same direction were collected in Mg2+ solutions, while flat films with some fibrils were achieved in K+ solutions. The Hofmeister series and Collins’ model were adapted to explain the effects of cations and acetate on the self-assembly of collagen. These results and analysis would be helpful for directing the pattern of collagen assembly on a solid surface with a potential application in food science and engineering.

In situ studies of thiol self-assembly on gold from solution using atomic force microscopy

1998 ◽  
Vol 108 (12) ◽  
pp. 5002-5012 ◽  
Author(s):  
Song Xu ◽  
Sylvain J. N. Cruchon-Dupeyrat ◽  
Jayne C. Garno ◽  
Gang-Yu Liu ◽  
G. Kane Jennings ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Force Microscopy ◽  
In Situ Studies ◽  
Atomic Force

scholarly journals Pathway Complexity in Supramolecular Porphyrin Self-Assembly at an Immiscible Liquid|Liquid Interface

2021 ◽  
Author(s):  
Iván Robayo-Molina ◽  
Andrés F. Molina-Osorio ◽  
Luke Guinane ◽  
Syed A.M. Tofail ◽  
Micheal D. Scanlon
Keyword(s):  
Self Assembly ◽  
Immiscible Liquid ◽  
Bulk Solution ◽  
Time Resolved ◽  
Force Microscopy ◽  
Atomic Force ◽  
Aggregate Growth ◽  
High Concentrations ◽  
Thermodynamic Processes

<p>Nanostructures that are inaccessible through spontaneous thermodynamic processes may be formed by supramolecular self-assembly under kinetic control. In the past decade, the dynamics of pathway complexity in self-assembly have been elucidated through kinetic models based on aggregate growth by sequential monomer association and dissociation. Immiscible liquid|liquid interfaces are an attractive platform to develop well-ordered self-assembled nanostructures, unattainable in bulk solution, due to the templating interaction of the interface with adsorbed molecules. Here, we report time-resolved <i>in situ</i> UV/vis spectroscopic observations of the self-assembly of zinc(II) meso-tetrakis(4-carboxyphenyl)porphyrin (ZnTPPc) at an immiscible aqueous|organic interface. We show that the kinetically favoured metastable J-type nanostructures form quickly, but then transform into stable thermodynamically favoured H-type nanostructures. Numerical modelling revealed two parallel and competing cooperative pathways leading to the different porphyrin nanostructures. These insights demonstrate that pathway complexity is not unique to self-assembly processes in bulk solution, and equally valid for interfacial self-assembly. Subsequently, the interfacial electrostatic environment was tuned using a kosmotropic anion (citrate) in order to control the influence the pathway selection. At high concentrations, interfacial nanostructure formation was forced completely down the kinetically favoured pathway and only J-type nanostructures were obtained. Furthermore, we found by atomic force microscopy (AFM) and scanning electron microscopy (SEM) that the J- and H-type nanostructures obtained at low and high citric acid concentrations, respectively, are morphologically distinct, which illustrates the pathway-dependent material properties.</p>

scholarly journals Observing Effects of Calcium/Magnesium Ions and pH Value on the Self-Assembly of Extracted Swine Tendon Collagen by Atomic Force Microscopy

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xuan Song ◽  
Zhiwei Wang ◽  
Shiyu Tao ◽  
Guixia Li ◽  
Jie Zhu
Keyword(s):  
Atomic Force Microscopy ◽  
Metal Ions ◽  
Self Assembly ◽  
Food Packaging ◽  
Ph Value ◽  
The Self ◽  
Solution Ph ◽  
Collagen Concentration ◽  
Force Microscopy ◽  
Atomic Force

Self-assembly of extracted collagen from swine trotter tendon under different conditions was firstly observed using atomic force microscopy; then the effects of collagen concentration, pH value, and metal ions to the topography of the collagen assembly were analyzed with the height images and section analysis data. Collagen assembly under 0.1 M, 0.2 M, 0.3 M CaCl2, and MgCl2 solutions in different pH values showed significant differences (P < 0.05) in the topographical properties including height, width, and roughness. With the concentration being increased, the width of collagen decreased significantly (P < 0.05). The width of collagen fibers was first increased significantly (P < 0.05) and then decreased with the increasing of pH. The collagen was assembled with network structure on the mica in solution with Ca2+ ions. However, it had shown uniformed fibrous structure with Mg2+ ions on the new cleaved mica sheet. In addition, the width of collagen fibrous was 31~58 nm in solution with Mg2+ but 21~50 nm in Ca2+ solution. The self-assembly collagen displayed various potential abilities to construct fibers or membrane on mica surfaces with Ca2+ ions and Mg2+ irons. Besides, the result of collagen self-assembly had shown more relations among solution pH value, metal ions, and collagen molecular concentration, which will provide useful information on the control of collagen self-assembly in tissue engineering and food packaging engineering.

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