scholarly journals Comprehensive multidimensional study of the self-assembly properties of a three residue substituted β3 oligoamide

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Claire Buchanan ◽  
Mark G. Hinds ◽  
Ljiljana Puskar ◽  
Christopher J. Garvey ◽  
Adam Mechler
Keyword(s):  
Self Assembly ◽  
Dynamic Equilibrium ◽  
Solid Phase ◽  
The Self ◽  
Cross Sectional ◽  
Self Assembling ◽  
Large Populations ◽  
Oligomeric Form ◽  
Fibre Growth ◽  
Fibrous Assemblies

Abstract Substituted β3 oligoamides form a unique self-assembling system where each monomer folds into a helix containing approximately three β3 amino acids per turn, yielding a geometrically well-defined cylindrical building block that, when N-acylated, is able to self-assemble head-to-tail into nanorods that can reach several 100 μm length. It was shown in previous works that self-assembly can be achieved with a three residue long oligoamide as well that lacks any intramolecular H-bonds, yet it crystallizes in a helix-like conformation. The self-assembly properties of these small oligoamides are however elusive, suggesting a more complex system than the self-assembly of the H-bond stabilized helical monomers. Here we focus on the self-assembly behaviour of a three residue oligoamide, Ac-β3[LIA] where the letters denote the side chain of the analogous α amino acid. Ac-β3[LIA] can yield highly inhomogeneous suspensions in water with a broad range of large fibrous structures that seem to be very stable, yet occasionally fibre growth is only observed upon heating. The small size of the monomer suggests a highly dynamic equilibrium yet all previous attempts failed to clearly identify low molecular weight species. Therefore a special methodology was employed in this study to characterize the suspensions at different size ranges: SANS that is optimal to measure the small oligomers and cross sectional diameter of the assemblies, DLS that is sensitive to the large populations and therefore the length of the superstructures, and NMR that is sensitive to monomeric and small oligomeric form, in conjunction with IR spectroscopy to probe the folding and AFM to image the morphology of the assemblies. Temperature ramping was used to perturb the system to probe the dynamicity of the self-assembly. It was found that the anomalous self-assembly behaviour of Ac-β3[LIA] is caused by its two stable conformations, a helix-building “horseshoe” fold and a linear conformer. The latter is exclusively found in monomeric form in solution whereas the horseshoe fold is stable in solid phase and in fibrous assemblies. Small oligomers were absent. Thus the self-assembly of Ac-β3[LIA] is arrested by the activation energy need of the conformation change; fibre growth might be triggered by conditions that allow increased conformational freedom of the monomers. This observation may be used to develop strategies for controlled switchable self-assembly.

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.

scholarly journals Unusual Aggregation Properties of Single Amino Acid L-Lysine Hydrochloride

2021 ◽  
Author(s):  
Bharti Koshti ◽  
Ramesh Singh ◽  
Vivekshinh Kshtriya ◽  
Shanka Walia ◽  
Dhiraj Bhatia ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Short Term Memory ◽  
Deionized Water ◽  
The Body ◽  
The Self ◽  
Single Amino Acid ◽  
Maple Syrup ◽  
Self Assembling

<p>.<br></p><p>The self-assembly of single amino acids is very important topic of research since there are plethora of diseases like phenylketonuria, tyrosinemia, hypertryptophanemia, hyperglycinemia, cystinuria and maple syrup urine disease to name a few which are caused by the accumulation or excess of amino acids. These are in-born errors of metabolisms (IEM’s) which are caused due to the deficiency of enzymes involved in catabolic pathways of these enzymes. Hence, it is very pertinent to understand the fate of these excess amino acids in the body and their self-assembling behaviour at molecular level. From the previous literature reports it may be surmised that the single amino acids like Phenylalanine, Tyrosine, Tryptophan, Cysteine and Methionine assemble to amyloid like structures, and hence have important implications in the pathophysiology of IEM’s like phenylketonuria, tyrosinemia, hypertryptophanemia, cystinuria and hypermethioninemia respectively. In this manuscript we report the self-assembly of lysine hydrocholride to fiber like structures in deionized water. It could be observed that lysine assemble to globular structures in fresh condition and then gradually changes to fiber like morphologies by self-association over time after 24 hours. These fibers gradually change to tubular morphologies after 3 day followed by fractal irregular morphologies in 10 and 15 days respectively. Notably, lysine exists as positively charged amino acid at physiological pH and the amine groups in lysine remain protonated. Hence, the self-assembling properties of lysine hydrochloride in deionized water is also pertinent and give insights into the fate of this amino acid in body in case it remains unmetabolized. Further, MTT assays were done to analyse the toxicities of these aggregates and the assay suggest their cytotoxic nature on SHSY5Y neural cell lines. Hence, the aggregation of lysine may be attributed to the pathological symptoms caused in diseases like hyperlysinemia which is associated with the neurological problems like seizures and short-term memory as observed in case of amyloid diseases like Parkinson’s and Alzheimer’s to name a few.</p>

The self-assembly and secondary structure of peptide amphiphiles determine the membrane permeation activity

RSC Advances ◽  
2014 ◽  
Vol 4 (58) ◽  
pp. 30654-30657 ◽  
Author(s):  
Rie Wakabayashi ◽  
Yuko Abe ◽  
Noriho Kamiya ◽  
Masahiro Goto
Keyword(s):  
Secondary Structure ◽  
Membrane Permeability ◽  
Self Assembly ◽  
The Self ◽  
Peptide Amphiphiles ◽  
Membrane Permeation ◽  
Related Peptide ◽  
Self Assembling

New GALA-related peptide amphiphiles were designed and the influence of their self-assembling propensity and the secondary structure on the membrane permeability was studied.

scholarly journals Self-assembly study of type I collagen extracted from male Wistar Hannover rat tail tendons

2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Jeimmy González-Masís ◽  
Jorge M. Cubero-Sesin ◽  
Simón Guerrero ◽  
Sara González-Camacho ◽  
Yendry Regina Corrales-Ureña ◽  
...  
Keyword(s):  
Regenerative Medicine ◽  
Self Assembly ◽  
Type I Collagen ◽  
Ph Effect ◽  
The Self ◽  
Titration Calorimetry ◽  
Type I ◽  
Self Assembling ◽  
Functional Features ◽  
Rat Tail

Abstract Background Collagen, the most abundant protein in the animal kingdom, represents a promising biomaterial for regenerative medicine applications due to its structural diversity and self-assembling complexity. Despite collagen’s widely known structural and functional features, the thermodynamics behind its fibrillogenic self-assembling process is still to be fully understood. In this work we report on a series of spectroscopic, mechanical, morphological and thermodynamic characterizations of high purity type I collagen (with a D-pattern of 65 nm) extracted from Wistar Hannover rat tail. Our herein reported results can be of help to elucidate differences in self-assembly states of proteins using ITC to improve the design of energy responsive and dynamic materials for applications in tissue engineering and regenerative medicine. Methods Herein we report the systematic study on the self-assembling fibrillogenesis mechanism of type I collagen, we provide morphological and thermodynamic evidence associated to different self-assembly events using ITC titrations. We provide thorough characterization of the effect of pH, effect of salts and protein conformation on self-assembled collagen samples via several complementary biophysical techniques, including circular dichroism (CD), Fourier Transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). Results Emphasis was made on the use of isothermal titration calorimetry (ITC) for the thermodynamic monitoring of fibrillogenesis stages of the protein. An overall self-assembly enthalpy value of 3.27 ± 0.85 J/mol was found. Different stages of the self-assembly mechanism were identified, initial stages take place at pH values lower than the protein isoelectric point (pI), however, higher energy release events were recorded at collagen’s pI. Denatured collagen employed as a control exhibited higher energy absorption at its pI, suggesting different energy exchange mechanisms as a consequence of different aggregation routes. Graphical abstract

scholarly journals 2-Deoxyglucose-Modified Folate Derivative: Self-Assembling Nanoparticle Able to Load Cisplatin

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1084 ◽  
Author(s):  
Shaoming Jin ◽  
Zhongyao Du ◽  
Pengjie Wang ◽  
Huiyuan Guo ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Folic Acid ◽  
Self Assembly ◽  
Water Solubility ◽  
Pure Water ◽  
The Self ◽  
Molar Ratio ◽  
Antineoplastic Drugs ◽  
Self Assembling ◽  
Bonding Interaction ◽  
Nano Drug Delivery

Folic acid has been widely introduced into nano-drug delivery systems to give nanoparticle-targeted characteristics. However, the poor water solubility of folic acid may hinder the exploitation of its ability to load antineoplastic drugs. In the present study, we designed a new folate derivative (FA-2-DG) synthesized from folic acid and 2-Deoxyglucose (2-DG). The aim of this study was to evaluate the self-assembly characteristics of FA-2-DG, and its ability of loading cisplatin. The critical micelle concentration was 7.94 × 10−6 mol L−1. Fourier transform infrared spectroscopy indicated that hydrogen bonding interaction is a main driving force for the self–assembly of FA-2-DG. The particle was stable in pure water or 0.5% bovine serum albumin dispersions. By forming a coordination bond, the particles assembled from FA-2-DG can load cisplatin. The loading efficiency was maximal when the molar ratio of FA-2-DG to cisplatin was 2:1.

scholarly journals Tunable Supramolecular Chirogenesis in the Self-Assembling of Amphiphilic Porphyrin Triggered by Chiral Amines

2020 ◽  
Vol 21 (22) ◽  
pp. 8557
Author(s):  
Marco Savioli ◽  
Manuela Stefanelli ◽  
Gabriele Magna ◽  
Francesca Zurlo ◽  
Maria Federica Caso ◽  
...  
Keyword(s):  
Self Assembly ◽  
Hydrophobic Effect ◽  
The Self ◽  
Chiral Amines ◽  
Solvent Mixtures ◽  
Fractal Structures ◽  
Chiral Amine ◽  
Supramolecular Chirality ◽  
Self Assembling ◽  
Aqueous Solvent

Supramolecular chirality is one of the most important issues in different branches of science and technology, as stereoselective molecular recognition, catalysis, and sensors. In this paper, we report on the self-assembly of amphiphilic porphyrin derivatives possessing a chiral information on the periphery of the macrocycle (i.e., D- or L-proline moieties), in the presence of chiral amines as co-solute, such as chiral benzylamine derivatives. The aggregation process, steered by hydrophobic effect, has been studied in aqueous solvent mixtures by combined spectroscopic and topographic techniques. The results obtained pointed out a dramatic effect of these ligands on the morphology and on the supramolecular chirality of the final self-assembled structures. Scanning electron microscopy topography, as well as fluorescence microscopy studies revealed the formation of rod-like structures of micrometric size, different from the fractal structures formerly observed when the self-assembly process is carried out in the absence of chiral amine co-solutes. On the other hand, comparative experiments with an achiral porphyrin analogue strongly suggested that the presence of the prolinate moiety is mandatory for the achievement of the observed highly organized suprastructures. The results obtained would be of importance for unraveling the intimate mechanisms operating in the selection of the homochirality, and for the preparation of sensitive materials for the detection of chiral analytes, with tunable stereoselectivity and morphology.

scholarly journals Molecular Determinants for the Self-Assembly of Elastin Peptides

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Brigida Bochicchio ◽  
Maria Rosaria Armenante ◽  
Maria Antonietta Crudele ◽  
Antonietta Pepe
Keyword(s):  
Molecular Structure ◽  
Mechanical Properties ◽  
Self Assembly ◽  
Terminal Region ◽  
The Self ◽  
Experimental Conditions ◽  
Self Assembling ◽  
Terminal Fragment ◽  
Aggregation Pattern ◽  
Molecular Determinants

Elastin and elastin-related peptides have great potential in the biomaterial field, because of their peculiar mechanical properties and spontaneous self-assembling behavior. Depending on their sequences and under appropriate experimental conditions, they are able to self-assemble in different fiber morphologies, including amyloid-like fibers. In this work, we will review recent data on elastin peptides derived from exon 30-coded domain of human tropoelastin. This domain has been shown to be fundamental for the correct assembly of elastin. However, the N-terminal region forms amyloid-like fibers, while the C-terminal fragment forms elastin-like fibers. A rationale for the varied aggregation pattern has been sought in the molecular structure of the peptides. Minimal differences in the sequences, adopting alternative conformations, are shown to be responsible for the observed data.

The Mechanism and Feasibility of Self-Assembly with Capillary Force

2007 ◽  
Vol 339 ◽  
pp. 234-239 ◽  
Author(s):  
D.P. Zhao ◽  
D. Wu ◽  
K. Chen
Keyword(s):  
Self Assembly ◽  
Binding Sites ◽  
Capillary Force ◽  
Capillary Forces ◽  
Interfacial Free Energy ◽  
The Self ◽  
Material System ◽  
Self Assembling ◽  
Hydrophilic Material ◽  
Micro Parts

This paper introduces a fluidic technique based on patterned shapes of hydrophobic self-assembly monolayers (SAMs) and capillary forces to self-assemble micro-parts onto substrates. Self-assembly is defined as a spontaneous process that occurs in a statistical, non-guided fashion. More specifically, the fluidic self-assembly with capillary force is driven by the gradient in interfacial free energy when a micro-part approaches a substrate binding site. In this paper, the mechanism of self-assembly with capillary forces is proposed. The hydrophobic-hydrophilic material system between the binding sites and micro-parts is then simulated. Finally, the surface energy of a self-assembling system in the liquid phase under different conditions is calculated. The results show that shift, twist, lift and tilts displacements are detected to be rather uncritical and the system turns out to be rather stiff with respect to such displacements. The theoretical result is supported by the experiments and gives quantitive explanations why and how the capillary force works in the self-assembly process.

Dissipative Particle Dynamics Studies on the Self-Assembling Dynamics of the Peptide Amphiphiles

2008 ◽  
Vol 1135 ◽  
Author(s):  
Taiga Seki ◽  
Noriyoshi Arai ◽  
Taku Ozawa ◽  
Tomoko Shimada ◽  
Kenji Yasuoka ◽  
...  
Keyword(s):  
Self Assembly ◽  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
The Self ◽  
Peptide Amphiphiles ◽  
Coarse Grained ◽  
Coarse Grained Model ◽  
Self Assembling ◽  
Micro Structures ◽  
Good Agreement

ABSTRACTA coarse-grained model of peptide amphiphiles (PA) dissolved in aqueous solution was presented, where the effects of PA concentration, temperature and shear stress upon the self-assembly of PA were numerically studied by dissipative particle dynamics (DPD) simulation. We technically investigate the repulsion parameter aHW which indicates the repulsion force between the hydrophilic head of PA and water molecules, hence, at the same time, indicating the change in temperature. It was found that aHW played an important role in the self-assembly dynamics and in the resulting micro-structures of PA. By imposing shear strain on the simulation system, the formation of wormlike PA micelles was accelerated. The simulation results were in good agreement with our previous experimental results and the mechanism of shear-induced transition was proposed.

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