Mechanistic Study of Self-Assembling Peptide RADA16-I in Formation of Nanofibers and Hydrogels

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Hangyu Zhang ◽  
Hanlin Luo ◽  
Xiaojun Zhao
Keyword(s):  
Self Assembly ◽  
Physiological Condition ◽  
Biochemical Properties ◽  
Low Ph ◽  
Repulsive Force ◽  
Mechanistic Study ◽  
Peptide Backbone ◽  
Self Assembling ◽  
Phosphate Buffered Saline ◽  
Β Sheet

The biophysical and biochemical properties of RADA16-I, the representative of a class of self-assembling peptides, were studied to elucidate the molecular mechanism of nanofiber and hydrogel formations. We found that self-assembly occurs in the solution at low pH (pH 4), rather than the popular belief that it occurs in the physiological environment. Actually, the peptide lost its β-sheet structure and formed irregular aggregates in the condition around pH 7. Our results demonstrated that the extended conformation of peptide backbone caused by the electrostatic repulsive force in acid solution is crucial for the peptide to self-assemble into nanofibers. Importantly, we have proposed a mechanism for the peptide to form nanofiber hydrogel in the physiological condition, which is not propitious for nanofiber formation. Hypothetically, it is by virtue of the tendency of fibers to collapse and form irregular aggregates at pH 7 that we could obtain stable hydrogels by introducing phosphate buffered saline into the system.

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 Experimental and Computational Investigation of the Structure of Peptide Monolayers on Gold Nanoparticles

2016 ◽  
Author(s):  
Elena Colangelo ◽  
Qiubo Chen ◽  
Adam M. Davidson ◽  
David Paramelle ◽  
Michael B. Sullivan ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Secondary Structure ◽  
Small Molecules ◽  
Self Assembly ◽  
Gold Surface ◽  
Biochemical Properties ◽  
Computational Investigation ◽  
Predictive Tool ◽  
Dynamics Simulations ◽  
Β Sheet

ABSTRACTThe self-assembly and self-organization of small molecules at the surface of nanoparticles constitute a potential route towards the preparation of advanced protein-like nanosystems. However, their structural characterization, critical to the design of bio-nanomaterials with well-defined biophysical and biochemical properties, remains highly challenging. Here, a computational model for peptide-capped gold nanoparticles is developed using experimentally characterized CALNN-and CFGAILSS-capped gold nanoparticles as a benchmark. The structure of CALNN and CFGAILSS monolayers is investigated by both structural biology techniques and molecular dynamics simulations. The calculations reproduce the experimentally observed dependence of the monolayer secondary structure on peptide capping density and on nanoparticle size, thus giving us confidence in the model. Furthermore, the computational results reveal a number of new features of peptide-capped monolayers, including the importance of sulfur movement for the formation of secondary structure motifs, the presence of water close to the gold surface even in tightly packed peptide monolayers, and the existence of extended 2D parallel β-sheet domains in CFGAILSS monolayers. The model developed here provides a predictive tool that may assist in the design of further bio-nanomaterials.

The fabrication of self-assembling peptides into nanofiber scaffolds through molecular self-assembly

2004 ◽  
Vol 820 ◽  
Author(s):  
Xiaojun Zhao ◽  
Jessica Dai ◽  
Shuguang Zhang
Keyword(s):  
Cell Cultures ◽  
Self Assembly ◽  
Rational Design ◽  
Biophysical Properties ◽  
Ph Values ◽  
Nanofiber Scaffold ◽  
Self Assembling ◽  
Nanofiber Scaffolds ◽  
D Cell ◽  
Β Sheet

AbstractWe designed and fabricated a class of self-assembling peptides into nanofiber scaffolds. KLDL-12 has been shown to be a permissible nanofiber scaffold for chondrocytes in cartilage 3-D cell cultures. However, the biochemical, structural, and biophysical properties of KLDL- 12 remain unclear. We show that KLDL-12 peptides form stable β-sheet structures at different pH values and that KLDL-12 and RIDI-12 self-assemble into nanofibers. The nanofiber length, though, is sensitive to pH changes. These results not only suggest the importance of electrostatic attraction or repulsion affecting the fiber lengths but also provide us with useful information for rational design and fabrication of peptide scaffolds.

scholarly journals Control over the fibrillization yield by varying the oligomeric nucleation propensities of self-assembling peptides

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Chun Yin Jerry Lau ◽  
Federico Fontana ◽  
Laurens D. B. Mandemaker ◽  
Dennie Wezendonk ◽  
Benjamin Vermeer ◽  
...  
Keyword(s):  
Thermodynamic Stability ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Supramolecular Assemblies ◽  
Mechanistic Studies ◽  
Molecular Changes ◽  
Self Assembling ◽  
Charged Residues ◽  
Β Sheet

AbstractSelf-assembling peptides are an exemplary class of supramolecular biomaterials of broad biomedical utility. Mechanistic studies on the peptide self-assembly demonstrated the importance of the oligomeric intermediates towards the properties of the supramolecular biomaterials being formed. In this study, we demonstrate how the overall yield of the supramolecular assemblies are moderated through subtle molecular changes in the peptide monomers. This strategy is exemplified with a set of surfactant-like peptides (SLPs) with different β-sheet propensities and charged residues flanking the aggregation domains. By integrating different techniques, we show that these molecular changes can alter both the nucleation propensity of the oligomeric intermediates and the thermodynamic stability of the fibril structures. We demonstrate that the amount of assembled nanofibers are critically defined by the oligomeric nucleation propensities. Our findings offer guidance on designing self-assembling peptides for different biomedical applications, as well as insights into the role of protein gatekeeper sequences in preventing amyloidosis.

The fabrication of self-assembling peptides into nanofiber scaffolds through molecular self-assembly

2004 ◽  
Vol 823 ◽  
Author(s):  
Xiaojun Zhao ◽  
Jessica Dai ◽  
Shuguang Zhang
Keyword(s):  
Cell Cultures ◽  
Self Assembly ◽  
Rational Design ◽  
Biophysical Properties ◽  
Ph Values ◽  
Nanofiber Scaffold ◽  
Self Assembling ◽  
Nanofiber Scaffolds ◽  
D Cell ◽  
Β Sheet

AbstractWe designed and fabricated a class of self-assembling peptides into nanofiber scaffolds. KLDL-12 has been shown to be a permissible nanofiber scaffold for chondrocytes in cartilage 3-D cell cultures. However, the biochemical, structural, and biophysical properties of KLDL-12 remain unclear. We show that KLDL-12 peptides form stable β-sheet structures at different pH values and that KLDL-12 and RIDI-12 self-assemble into nanofibers. The nanofiber length, though, is sensitive to pH changes. These results not only suggest the importance of electrostatic attraction or repulsion affecting the fiber lengths but also provide us with useful information for rational design and fabrication of peptide scaffolds.

scholarly journals An S/T motif controls reversible oligomerization of the Hsp40 chaperone DNAJB6b through subtle reorganization of a β sheet backbone

2020 ◽  
Vol 117 (48) ◽  
pp. 30441-30450
Author(s):  
Theodoros K. Karamanos ◽  
Vitali Tugarinov ◽  
G. Marius Clore
Keyword(s):  
Self Assembly ◽  
Nmr Relaxation ◽  
Relaxation Dispersion ◽  
Nmr Studies ◽  
Self Assembling ◽  
Critical Residues ◽  
Nmr Methods ◽  
Β Sheet

Chaperone oligomerization is often a key aspect of their function. Irrespective of whether chaperone oligomers act as reservoirs for active monomers or exhibit a chaperoning function themselves, understanding the mechanism of oligomerization will further our understanding of how chaperones maintain the proteome. Here, we focus on the class-II Hsp40, human DNAJB6b, a highly efficient inhibitor of protein self-assembly in vivo and in vitro that forms functional oligomers. Using single-quantum methyl-based relaxation dispersion NMR methods we identify critical residues for DNAJB6b oligomerization in its C-terminal domain (CTD). Detailed solution NMR studies on the structure of the CTD showed that a serine/threonine-rich stretch causes a backbone twist in the N-terminal β strand, stabilizing the monomeric form. Quantitative analysis of an array of NMR relaxation-based experiments (including Carr–Purcell–Meiboom–Gill relaxation dispersion, off-resonanceR1ρprofiles, lifetime line broadening, and exchange-induced shifts) on the CTD of both wild type and a point mutant (T142A) within the S/T region of the first β strand delineates the kinetics of the interconversion between the major twisted-monomeric conformation and a more regular β strand configuration in an excited-state dimer, as well as exchange of both monomer and dimer species with high-molecular-weight oligomers. These data provide insights into the molecular origins of DNAJB6b oligomerization. Further, the results reported here have implications for the design of β sheet proteins with tunable self-assembling properties and pave the way to an atomic-level understanding of amyloid inhibition.

Preparation and Characterization of Poly-γ-Glutamic Acid-Based Nanoparticles Biomacromolecules

2014 ◽  
Vol 915-916 ◽  
pp. 891-894
Author(s):  
Ge Yang ◽  
Ke Shuai Lu ◽  
Xue Yan Su
Keyword(s):  
Glutamic Acid ◽  
Surface Charge ◽  
Size Distribution ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Low Ph ◽  
Biodegradable Nanoparticles ◽  
Self Assembling ◽  
Ph Conditions

The present paper describes the preparation and characterization of novel biodegradable nanoparticles based on self-assembly of poly-γ-glutamic acid (γ-PGA). The nanosystems were stable inaqueous media at low pH conditions. Solubility of the systems was determined by turbidity measurements. Surface charge and mobility were measured electrophoretically. It was found that the size and size distribution of the nanosystems depends on the concentrations of γ-PGA solutions and their ratio as well as on the pH of the mixture and the order of addition. The average hydrodynamic diameters were between 150 and 330 nm. These biodegradable,self-assembling stable nanocomplexes might be useful for several biomedical applications.

Factors Affecting Molecular Self-Assembly and Its Mechanism

2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Molecular Engineering ◽  
Molecular Structures ◽  
Polymer Science ◽  
New Approach ◽  
Factors Affecting ◽  
Dna Structures ◽  
Self Assembling ◽  
Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Light Scattering ◽  
Chain Length ◽  
Self Assembly ◽  
The Self ◽  
Ionic Charge ◽  
Self Assembling ◽  
Biophysical Techniques

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.

Self-assembling behaviour of a modified aromatic amino acid in competitive medium

Soft Matter ◽  
2020 ◽  
Vol 16 (28) ◽  
pp. 6599-6607 ◽  
Author(s):  
Pijush Singh ◽  
Souvik Misra ◽  
Nayim Sepay ◽  
Sanjoy Mondal ◽  
Debes Ray ◽  
...  
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acid ◽  
Photophysical Properties ◽  
Solvent Mixture ◽  
The Self ◽  
Solvent Ratio ◽  
Self Assembling

The self-assembly and photophysical properties of 4-nitrophenylalanine (4NP) are changed with the alteration of solvent and final self-assembly state of 4NP in competitive solvent mixture and are dictated by the solvent ratio.

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