Isomeric effect in the self-assembly of pyridine-containing L-glutamic lipid: substituent position controlled morphology and supramolecular chirality

2011 ◽  
Vol 47 (19) ◽  
pp. 5569 ◽  
Author(s):  
Pengfei Duan ◽  
Xuefeng Zhu ◽  
Minghua Liu
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Supramolecular Chirality ◽  
Controlled Morphology ◽  
Isomeric Effect

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.

Link spacer controlled supramolecular chirality of perylene bisimide-carbohydrate conjugate

RSC Advances ◽  
2015 ◽  
Vol 5 (59) ◽  
pp. 47728-47731 ◽  
Author(s):  
Ke-Rang Wang ◽  
Dan Han ◽  
Guo-Jing Cao ◽  
Xiao-Liu Li
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amide Bond ◽  
Perylene Bisimide ◽  
Supramolecular Chirality ◽  
Left Handed

Controllable supramolecular chirality based on the self-assembly of the perylene bisimide-carbohydrate conjugates was achieved, exhibiting right-handed chirality with triazole as linker and left-handed chirality with the amide bond as linker.

scholarly journals Symmetry Breaking in Self-Assembled Nanoassemblies

Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 950 ◽  
Author(s):  
Yutao Sang ◽  
Minghua Liu
Keyword(s):  
Symmetry Breaking ◽  
Self Assembly ◽  
Mirror Symmetry ◽  
Covalent Bond ◽  
The Self ◽  
Control Methods ◽  
Supramolecular Chirality ◽  
Dispersed System ◽  
Chiral Materials ◽  
And Control

The origin of biological homochirality, e.g., life selects the L-amino acids and D-sugar as molecular component, still remains a big mystery. It is suggested that mirror symmetry breaking plays an important role. Recent researches show that symmetry breaking can also occur at a supramolecular level, where the non-covalent bond was crucial. In these systems, equal or unequal amount of the enantiomeric nanoassemblies could be formed from achiral molecules. In this paper, we presented a brief overview regarding the symmetry breaking from dispersed system to gels, solids, and at interfaces. Then we discuss the rational manipulation of supramolecular chirality on how to induce and control the homochirality in the self-assembly system. Those physical control methods, such as Viedma ripening, hydrodynamic macro- and micro-vortex, superchiral light, and the combination of these technologies, are specifically discussed. It is hoped that the symmetry breaking at a supramolecular level could provide useful insights into the understanding of natural homochirality and further designing as well as controlling of functional chiral materials.

Chirality inversion in hydrogen-bonded rhodanine-oligothiophene derivatives by solvent and temperature

2021 ◽  
Author(s):  
Amparo Ruiz-Carretero ◽  
Ana Maria Garcia
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Assembly Process ◽  
Supramolecular Chirality ◽  
Hydrogen Bonded

The self-assembly process of hydrogen-bonded quinquethiophene-rhodanine derivatives has been explored as a function of solvent and temperature. We demonstrate the divergent supramolecular chirality emerging from a single enantiomer by subtle...

Tuning of gel morphology with supramolecular chirality amplification using a solvent strategy based on an Fmoc-amino acid building block

2016 ◽  
Vol 40 (6) ◽  
pp. 5568-5576 ◽  
Author(s):  
Yimeng Zhang ◽  
Shangyang Li ◽  
Mingfang Ma ◽  
Minmin Yang ◽  
Yajie Wang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Building Block ◽  
Aromatic Amino Acid ◽  
The Self ◽  
Supramolecular Chirality

The self-assembly of an aromatic amino acid affords diverse aggregates from flat nanofibers to twist nanofibers with tunable supramolecular chirality.

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

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.

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

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.

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

MRS Advances ◽  
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.

Bottom-up Evolution from Disks to High-Genus Polymersomes

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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