scholarly journals Solid-state optical properties of self-assembling amyloid-like peptides with different charged states at the terminal ends

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Chiara Schiattarella ◽  
Carlo Diaferia ◽  
Enrico Gallo ◽  
Bartolomeo Della Ventura ◽  
Giancarlo Morelli ◽  
...  
Keyword(s):  
Solid State ◽  
Charge State ◽  
Spectroscopic Properties ◽  
The Self ◽  
Quantum Yields ◽  
Visible Range ◽  
Small Peptides ◽  
Self Assembling ◽  
Uv Visible ◽  
Pl Emission

AbstractThe self-assembling of small peptides not only leads to the formation of intriguing nanoarchitectures, but also generates materials with unexpected functional properties. Oligopeptides can form amyloid-like cross-β assemblies that are able to emit intrinsic photoluminescence (PL), over the whole near-UV/visible range, whose origin is still largely debated. As proton transfer between the peptide chain termini within the assembly is one of the invoked interpretations of this phenomenon, we here evaluated the solid state PL properties of a series of self-assembled hexaphenylalanine peptides characterized by a different terminal charge state. Overall, our data indicate that the charge state of these peptides has a marginal role in the PL emission as all systems exhibit very similar multicolour PL associated with a violation of the Kasha’s rule. On the other hand, charged/uncharged ends occasionally produce differences in the quantum yields. The generality of these observations has been proven by extending these analyses to the Aβ16–21 peptide. Collectively, the present findings provide useful information for deciphering the code that links the spectroscopic properties of these assemblies to their structural/electronic features.

scholarly journals Solid-State Optical Properties of Self-Assembling Amyloid-Like Peptides with Different Charged States at the Terminal Ends

2021 ◽  
Author(s):  
Chiara Schiattarella ◽  
Carlo Diaferia ◽  
Enrico Gallo ◽  
Bartolomeo Della Ventura ◽  
Giancarlo Morelli ◽  
...  
Keyword(s):  
Solid State ◽  
Charge State ◽  
Spectroscopic Properties ◽  
The Self ◽  
Quantum Yields ◽  
Visible Range ◽  
Small Peptides ◽  
Self Assembling ◽  
Uv Visible ◽  
Pl Emission

Abstract The self-assembling of small peptides not only leads to the formation of intriguing nanoarchitectures, but also generates materials with unexpected functional properties. Oligopeptides can form amyloid-like cross-β assemblies that are able to emit intrinsic photoluminescence (PL), over the whole near-UV/visible range, whose origin is still largely debated. As proton transfer between the peptide chain termini within the assembly is one of the invoked interpretations of this phenomenon, we here evaluated the solid state PL properties of a series of self-assembled hexaphenalanine peptides characterized by a different terminal charge state. Overall, our data indicate that the charge state of these peptides has a marginal role in the PL emission as all systems exhibit very similar multicolour PL associated with a violation of the Kasha’s rule. On the other hand, charged/uncharged ends occasionally produce differences in the quantum yields. The generality of these observations has been proven by extending these analyses to the Aβ16−21 peptide. Collectively, the present findings provide useful information for deciphering the code that links the spectroscopic properties of these assemblies to their structural/electronic features.

scholarly journals 5-Ureido-3,3-diphenyl-3H-naphtho[2,1-b]pyrans: Photoswitchable self-assembling architectures

2004 ◽  
Vol 6 (4) ◽  
pp. 169-173 ◽  
Author(s):  
X. Sallenave ◽  
S. Delbaere ◽  
S. Ahmed ◽  
G. Vermeersch ◽  
J. L. Pozzo
Keyword(s):  
Carbonyl Group ◽  
Uv Irradiation ◽  
2D Nmr ◽  
Intramolecular Interactions ◽  
The Self ◽  
Visible Spectroscopy ◽  
Photochromic Properties ◽  
Self Assembling ◽  
Amino Derivatives ◽  
Uv Visible

5-Ureido-3,3-diphenyl-3H-naphtho[2,1-b]pyrans have been synthesized and their photochromic properties have been quantified using UV-Visible spectroscopy. The urea pattern is responsive for the selfassembling properties under both colourless and coloured forms whereas the corresponding amino derivatives do not show any aggregative properties. The geometries of the different states have been assigned using1Hand19FNMR spectroscopies, and thereafter their respective kind of aggregates could be proposed through the different inter- and intramolecular interactions. Upon UV irradiation, the pyranic ring is opened and the resulting photogenerated carbonyl group is competing with the urea in the self-assembling process and consequently strongly affects the supramolecular assemblies. The inter- and intramolecular contributions have been quantified through 1D and 2D NMR experiments along with the variation in the concentration.

Magnetic and Optical Properties of Novel Lanthanide(III) Complexes Based on Schiff Base and β-Diketonate Ligands

2018 ◽  
Vol 71 (7) ◽  
pp. 527
Author(s):  
Yufeng Jia ◽  
Hongfeng Li ◽  
Peng Chen ◽  
Ting Gao ◽  
Wenbin Sun ◽  
...  
Keyword(s):  
Optical Properties ◽  
Schiff Base ◽  
Solid State ◽  
Single Molecule ◽  
Energy Barrier ◽  
Quantum Yields ◽  
Single Molecule Magnet ◽  
One Dimensional ◽  
Self Assembling ◽  
Magnetic Analysis

A series of lanthanide-based self-assembling complexes constructed from Schiff base and β-diketonate ligands have been synthesised by the same method. They are one dimensional complexes ({[Ln(H2L)(tta)2(OAc)]·0.5H2O}n (Ln = Eu (1), Gd (2), Dy (3), Yb (4)); H2L = N,N′-bis(salicylidene)butane-1,4-diamine, tta = 2-thenoyltrifluoroacetone). Complexes 1 and 4 exhibit characteristic metal-centred emission in the solid state. The lifetimes and quantum yields of luminescence were also determined. Magnetic analysis reveals that complex 3 exhibits field-induced single-molecule magnet (SMM) behaviour with an energy barrier of 24.07 K.

scholarly journals Chiral Self-Sorting in Truxene-Based Metallacages

Inorganics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
Simon Séjourné ◽  
Antoine Labrunie ◽  
Clément Dalinot ◽  
Amina Benchohra ◽  
Vincent Carré ◽  
...  
Keyword(s):  
Solid State ◽  
The Self ◽  
X Ray ◽  
X Ray Crystallography ◽  
Self Assembling ◽  
Sorting Process ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Two chiral face-rotating metalla-assembled polyhedra were constructed upon self-assembling achiral components, i.e., a tritopic ligand based on a truxene core (10,15-dihydro-5H-diindeno[1,2-a;1′,2′-c]fluorene) and two different hydroxyquinonato–bridged diruthenium complexes. Both polyhedra were characterized in solution as well as in the solid state by X-ray crystallography. In both cases, the self-sorting process leading to only two homo-chiral enantiomers was governed by non-covalent interactions between both truxene units that faced each other.

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.

A Solvent-Dependent and Electrochemically Controlled Self-Assembling/Disassembling System

2003 ◽  
Vol 68 (9) ◽  
pp. 1647-1662 ◽  
Author(s):  
Valeria Amendola ◽  
Massimo Boiocchi ◽  
Yuri Diaz Fernandez ◽  
Carlo Mangano ◽  
Piersandro Pallavicini
Keyword(s):  
Equilibrium Mixture ◽  
Bidentate Ligand ◽  
Molecular Structures ◽  
The Self ◽  
Molar Ratio ◽  
Crystal And Molecular Structures ◽  
Self Assembling ◽  
Irreversible Oxidation ◽  
Irreversible Reduction ◽  
Metal Ligand

The bis-bidentate ligand R,S-1,2-diphenyl-N,N'-bis(2-quinolinemethylidene)ethane-1,2-diamine (ligand 4), containing two (iminomethyl)quinoline moieties separated by a cis-1,2-diphenylethylene spacer, forms stable complexes with both CuI and CuII. With CuII, the monomeric 1:1 complex [CuII(4)]2+ is obtained both in CH3CN and CH2Cl2. With CuI and overall 1:1 metal/ligand molar ratio, an equilibrium mixture is obtained in CH3CN, consisting of [CuI(4)2]+, [CuI2(4)2]2+ and [CuI2(4)(CH3CN)4]2+. The preponderant species is the two-metal one-ligand "open" complex [CuI2(4)(CH3CN)4]2+, in which each Cu+ cation is coordinated in a tetrahedral fashion by one (iminomethyl)quinoline unit and by two CH3CN molecules. Precipitation from the equilibrium mixture yields only crystals of [CuI2(4)(CH3CN)4](ClO4)2·2CH3CN, whose crystal and molecular structures have been determined. On the other hand, in the poorly coordinating CH2Cl2 solvent, only the dimeric helical [CuI2(4)2]2+ complex is obtained, when the overall metal/ligand 1:1 molar ratio is chosen. Addition of large quantities of acetonitrile to solutions of [CuI2(4)2]2+ in dichlorometane results in the formation of [CuI2(4)(CH3CN)4]2+, i.e. in the solvent-driven disassembling of the CuI helicate. While electrochemistry in CH3CN is poorly defined due to the presence of more than one CuI species, cyclic voltammetry experiments carried out in CH2Cl2 revealed a well defined behavior, with irreversible oxidation of [CuI2(4)2]2+ and irreversible reduction of [CuII(4)]2+ taking place at separate potentials (∆E ≈ 700 mV). Irreversibility and separation of the redox events are due to the self-assembling and disassembling processes following the reduction and oxidation, respectively.

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 Regulating the Self‐Discharge of Flexible All‐Solid‐State Supercapacitors by a Heterogeneous Polymer Electrolyte (Small 31/2021)

Small ◽  
2021 ◽  
Vol 17 (31) ◽  
pp. 2170160
Author(s):  
Xue Wang ◽  
Yanan Liu ◽  
Huili Li ◽  
Tian Lv ◽  
Jun Wan ◽  
...  
Keyword(s):  
Solid State ◽  
Polymer Electrolyte ◽  
The Self ◽  
Heterogeneous Polymer

scholarly journals Self-assembling thermostable chimeras as new platform for arsenic biosensing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rosanna Puopolo ◽  
Ilaria Sorrentino ◽  
Giovanni Gallo ◽  
Alessandra Piscitelli ◽  
Paola Giardina ◽  
...  
Keyword(s):  
Inclusion Bodies ◽  
Association Constant ◽  
Immobilized Enzyme ◽  
Thermus Thermophilus ◽  
Chimeric Protein ◽  
The Self ◽  
Chimeric Proteins ◽  
Self Assembling ◽  
Langmuir Isotherm Model ◽  
Activity Loss

AbstractThe correct immobilization and orientation of enzymes on nanosurfaces is a crucial step either for the realization of biosensors, as well as to guarantee the efficacy of the developed biomaterials. In this work we produced two versions of a chimeric protein, namely ArsC-Vmh2 and Vmh2-ArsC, which combined the self-assembling properties of Vmh2, a hydrophobin from Pleurotus ostreatus, with that of TtArsC, a thermophilic arsenate reductase from Thermus thermophilus; both chimeras were heterologously expressed in Escherichia coli and purified from inclusion bodies. They were characterized for their enzymatic capability to reduce As(V) into As(III), as well as for their immobilization properties on polystyrene and gold in comparison to the native TtArsC. The chimeric proteins immobilized on polystyrene can be reused up to three times and stored for 15 days with 50% of activity loss. Immobilization on gold electrodes showed that both chimeras follow a classic Langmuir isotherm model towards As(III) recognition, with an association constant (KAsIII) between As(III) and the immobilized enzyme, equal to 650 (± 100) L mol−1 for ArsC-Vmh2 and to 1200 (± 300) L mol−1 for Vmh2-ArsC. The results demonstrate that gold-immobilized ArsC-Vmh2 and Vmh2-ArsC can be exploited as electrochemical biosensors to detect As(III).

Sign in / Sign up

Export Citation Format

Share Document