Peptide Nanovesicles Formed by the Self-Assembly of Branched Amphiphilic Peptides

Amphiphilic peptides with or without oligoethylene glycol (OEG) chains based on 3,4-bis(benzyloxy)benzoic-linked glutamide were designed and their self-assembly was investigated. It was found that the amphiphilic peptide 3 with OEG chains could not only form stable gels in a wide range of solvents, but also showed better solubility in solvents than those without OEG chains. Fibrillar and nanotube structures were found in the gels formed and the width of the fibres could be tuned with added water content. The UV-vis and XRD results suggested that the driving forces for the peptide self-assembly were mainly intermolecular π–π and hydrogen-bonding interactions. These results provide a deeper understanding of the self-assembly mechanism and size control of nanofibrils formed by an OEG-based amphiphilic peptide.

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Self-Assembly of Short Elastin-like Amphiphilic Peptides: Effects of Temperature, Molecular Hydrophobicity and Charge Distribution

Molecules ◽

10.3390/molecules24010202 ◽

2019 ◽

Vol 24 (1) ◽

pp. 202 ◽

Cited By ~ 10

Author(s):

Meiwen Cao ◽

Yang Shen ◽

Yu Wang ◽

Xiaoling Wang ◽

Dongxiang Li

Keyword(s):

Charge Distribution ◽

Self Assembly ◽

Temperature Increase ◽

The Self ◽

Assembly Process ◽

Amphiphilic Peptides ◽

Self Assembling ◽

Amphiphilic Peptide ◽

Effects Of Temperature ◽

Thermo Sensitivity

A novel type of self-assembling peptides has been developed by introducing the basic elastomeric β-turn units of elastin protein into the amphiphilic peptide molecules. The self-assembly behaviors of such peptides are affected by the overall molecular hydrophobicity, charge distribution and temperature. The molecules with higher hydrophobicity exhibit better self-assembling capability to form long fibrillar nanostructures. For some peptides, the temperature increase can not only promote the self-assembly process but also change the self-assembly routes. The self-assembly of the peptides with two charges centralized on one terminal show higher dependence on temperature than the peptides with two charges distributed separately on the two terminals. The study probes into the self-assembly behaviors of short elastin-like peptides and is of great help for developing novel self-assembling peptides with thermo sensitivity.

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Influence of elastase on alanine-rich peptide hydrogels

Biomaterials Science ◽

10.1039/c4bm00001c ◽

2014 ◽

Vol 2 (6) ◽

pp. 867-874 ◽

Cited By ~ 16

Author(s):

V. Castelletto ◽

R. J. Gouveia ◽

C. J. Connon ◽

I. W. Hamley ◽

J. Seitsonen ◽

...

Keyword(s):

Aqueous Solution ◽

Self Assembly ◽

The Self ◽

Amphiphilic Peptides ◽

Peptide Hydrogels

The self-assembly of the alanine-rich amphiphilic peptides Lys(Ala)6Lys (KA6K) and Lys(Ala)6Glu (KA6E) with homotelechelic or heterotelechelic charged termini respectively has been investigated in aqueous solution. The latter forms enzyme-degradable hydrogels.

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The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065870 ◽

1971 ◽

Vol 29 ◽

pp. 366-367

Author(s):

M. Kessel ◽

R. MacColl

Keyword(s):

Self Assembly ◽

Analytical Ultracentrifugation ◽

Uranyl Acetate ◽

The Self ◽

Major Protein ◽

Subunit Structure ◽

Blue Green Alga ◽

Thin Sections ◽

Blue Green Algae ◽

Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

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Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123969 ◽

1992 ◽

Vol 50 (1) ◽

pp. 712-713

Author(s):

Xiaorong Zhu ◽

Richard McVeigh ◽

Bijan K. Ghosh

Keyword(s):

Alkaline Phosphatase ◽

Bacillus Licheniformis ◽

Self Assembly ◽

Gel Electrophoresis ◽

Culture Supernatant ◽

Regular Structure ◽

The Self ◽

Cellular Distribution ◽

Structural Protein ◽

Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

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Nanoscale Self-Assembly Using Ion and Electron Beam Techniques: A Rapid Review

MRS Advances ◽

10.1557/adv.2020.349 ◽

2020 ◽

Vol 5 (64) ◽

pp. 3507-3520

Author(s):

Chunhui Dai ◽

Kriti Agarwal ◽

Jeong-Hyun Cho

Keyword(s):

Electron Beam ◽

Self Assembly ◽

Ion Beam ◽

Three Dimensional ◽

The Self ◽

Stress Generation ◽

Rapid Review ◽

High Yield ◽

3D Nanostructures ◽

Self Assembled

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.

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Bottom-up Evolution from Disks to High-Genus Polymersomes

10.26434/chemrxiv.6108467.v1 ◽

2018 ◽

Author(s):

Claudia Contini ◽

Russell Pearson ◽

Linge Wang ◽

Lea Messager ◽

Jens Gaitzsch ◽

...

Keyword(s):

Self Assembly ◽

The Self ◽

Amphiphilic Copolymers ◽

Chain Entanglement ◽

Bottom Up ◽

New Approach ◽

High Genus ◽

Transmission Electron ◽

Minimal Radius ◽

Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

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Bottom-up Evolution from Disks to High-Genus Polymersomes

10.26434/chemrxiv.6108467 ◽

2018 ◽

Author(s):

Claudia Contini ◽

Russell Pearson ◽

Linge Wang ◽

Lea Messager ◽

Jens Gaitzsch ◽

...

Keyword(s):

Self Assembly ◽

The Self ◽

Amphiphilic Copolymers ◽

Chain Entanglement ◽

Bottom Up ◽

New Approach ◽

High Genus ◽

Transmission Electron ◽

Minimal Radius ◽

Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

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Clathrin-Inspired Coating and Stabilization of Liposomes by DNA Self-Assembly

10.26434/chemrxiv.8859017.v1 ◽

2019 ◽

Author(s):

Kevin N. Baumann ◽

Luca Piantanida ◽

Javier García-Nafría ◽

Diana Sobota ◽

Kislon Voïtchovsky ◽

...

Keyword(s):

Self Assembly ◽

Mechanical Stability ◽

Lipid Vesicles ◽

The Self ◽

Force Microscopy ◽

Atomic Force ◽

Cryo Electron Microscopy ◽

Further Development ◽

Liposome Surface ◽

Dna Coating

The self-assembly of the protein clathrin on biological membranes facilitates essential processes of endocytosis in biological systems and has provided a source of inspiration for materials design by the highly ordered structural appearance. By mimicking the architecture of clathrin self-assemblies to coat liposomes with biomaterials, new classes of hybrid carriers can be derived. Here we present a method for fabricating DNA-coated liposomes by hydrophobically anchoring and subsequently growing a DNA network on the liposome surface which structurally mimics clathrin assemblies. Dynamic light scattering (DLS), ζ-potential and cryo-electron microscopy (cryo-EM) measurements independently demonstrate successful DNA coating. Nanomechanical measurements conducted with atomic force microscopy (AFM) show that the DNA coating enhances the mechanical stability of the liposomes relative to uncoated ones. Furthermore, we provide the possibility to reverse the coating process by triggering the disassembly of the DNA coating through a toehold-mediated displacement reaction. Our results describe a straightforward, versatile, and reversible approach for coating and stabilizing lipid vesicles by an interlaced DNA network. This method has potential for further development towards the ordered arrangement of tailored functionalities on the surfaces of liposomes and for applications as hybrid nanocarrier.

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