scholarly journals Supramolecular fibrillation of peptide amphiphiles induces environmental responses in aqueous droplets

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Richard Booth ◽  
Ignacio Insua ◽  
Sahnawaz Ahmed ◽  
Alicia Rioboo ◽  
Javier Montenegro
Keyword(s):  
Self Assembly ◽  
Chemical Exchange ◽  
Peptide Amphiphiles ◽  
Supramolecular Polymers ◽  
Functional Responses ◽  
One Dimensional ◽  
Molecular Ordering ◽  
Physico Chemical ◽  
Environmental Responses

AbstractOne-dimensional (1D) supramolecular polymers are commonly found in natural and synthetic systems to prompt functional responses that capitalise on hierarchical molecular ordering. Despite amphiphilic self-assembly being significantly studied in the context of aqueous encapsulation and autopoiesis, very little is currently known about the physico-chemical consequences and functional role of 1D supramolecular polymerisation confined in aqueous compartments. Here, we describe the different phenomena that resulted from the chemically triggered supramolecular fibrillation of synthetic peptide amphiphiles inside water microdroplets. The confined connection of suitable dormant precursors triggered a physically autocatalysed chemical reaction that resulted in functional environmental responses such as molecular uptake, fusion and chemical exchange. These results demonstrate the potential of minimalistic 1D supramolecular polymerisation to modulate the behaviour of individual aqueous entities with their environment and within communities.

scholarly journals Self-Assembly and Magnetic Order of Bi-Molecular 2D Spin Lattices of M(II,III) Phthalocyanines on Au(111)

2021 ◽  
Vol 7 (8) ◽  
pp. 119
Author(s):  
Miloš Baljozović ◽  
Xunshan Liu ◽  
Olha Popova ◽  
Jan Girovsky ◽  
Jan Nowakowski ◽  
...  
Keyword(s):  
Self Assembly ◽  
Present Report ◽  
Single Layer ◽  
Physico Chemical ◽  
Electronic Surface State ◽  
The Individual ◽  
Low Dimensional ◽  
Low Dimensional Materials ◽  
Electronic Surface

Single layer low-dimensional materials are presently of emerging interest, including in the context of magnetism. In the present report, on-surface supramolecular architecturing was further developed and employed to create surface supported two-dimensional binary spin arrays on atomically clean non-magnetic Au(111). By chemical programming of the modules, different checkerboards were produced combining phthalocyanines containing metals of different oxidation and spin states, diamagnetic zinc, and a metal-free ‘spacer’. In an in-depth, spectro-microscopy and theoretical account, we correlate the structure and the magnetic properties of these tunable systems and discuss the emergence of 2D Kondo magnetism from the spin-bearing components and via the physico-chemical bonding to the underlying substrate. The contributions of the individual elements, as well as the role of the electronic surface state in the bottom substrate, are discussed, also looking towards further in-depth investigations.

Supramolecular self-assembly and photovoltaic property of soluble fluorogallium phthalocyanine

RSC Advances ◽  
2014 ◽  
Vol 4 (56) ◽  
pp. 29485-29492 ◽  
Author(s):  
Jian Zhang ◽  
Yaowen Li ◽  
Laibing Wang ◽  
Michiya Fujiki ◽  
Xiaopeng Li ◽  
...  
Keyword(s):  
Solid State ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Self Assembly ◽  
Power Conversion ◽  
Photovoltaic Property ◽  
Supramolecular Polymers ◽  
One Dimensional ◽  
Coating Technique

Fluorogallium tetra-tert-butylphthalocyanine (ttbPcGaF) can self-organize into well-ordered cofacial structures to obtain one-dimensional (1D) supramolecular polymers in the solid state using a solution-coating technique. The ttbPcGaF-based BHJ OSC provided a profoundly improved power conversion efficiency (PCE) of 0.41%.

Role of Hydrophobicity on Self-Assembly by Peptide Amphiphiles via Molecular Dynamics Simulations

Langmuir ◽  
2014 ◽  
Vol 30 (26) ◽  
pp. 7745-7754 ◽  
Author(s):  
Iris W. Fu ◽  
Cade B. Markegard ◽  
Brian K. Chu ◽  
Hung D. Nguyen
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Self Assembly ◽  
Peptide Amphiphiles ◽  
Dynamics Simulations

scholarly journals Supramolecular polymerization of sulfated dendritic peptide amphiphiles into multivalent L-selectin binders

2021 ◽  
Vol 17 ◽  
pp. 97-104
Author(s):  
David Straßburger ◽  
Svenja Herziger ◽  
Katharina Huth ◽  
Moritz Urschbach ◽  
Rainer Haag ◽  
...  
Keyword(s):  
Self Assembly ◽  
Supramolecular Polymers ◽  
Supramolecular Polymer ◽  
Peptide Amphiphile ◽  
One Dimensional ◽  
Cryogenic Transmission Electron Microscopy ◽  
Naturally Occurring ◽  
Selectin Ligands ◽  
Transmission Electron ◽  
Supramolecular Polymerization

The synthesis of a sulfate-modified dendritic peptide amphiphile and its self-assembly into one-dimensional rod-like architectures in aqueous medium is reported. The influence of the ionic strength on the supramolecular polymerization was probed via circular dichroism spectroscopy and cryogenic transmission electron microscopy. Physiological salt concentrations efficiently screen the charges of the dendritic building block equipped with eight sulfate groups and trigger the formation of rigid supramolecular polymers. Since multivalent sulfated supramolecular structures mimic naturally occurring L-selectin ligands, the corresponding affinity was evaluated using a competitive SPR binding assay and benchmarked to an ethylene glycol-decorated supramolecular polymer.

Differentiating the mechanism of self-assembly in supramolecular polymers through computation

2019 ◽  
Vol 55 (26) ◽  
pp. 3773-3776 ◽  
Author(s):  
Divya B. Korlepara ◽  
Will R. Henderson ◽  
Ronald K. Castellano ◽  
Sundaram Balasubramanian
Keyword(s):  
Self Assembly ◽  
Supramolecular Polymers ◽  
Bulk Properties ◽  
One Dimensional

The mechanism by which monomers in solution, beyond a certain concentration or below a certain temperature, self-assemble to form one dimensional supramolecular polymers determines much of the bulk properties of the polymer.

Role of cooperative templates in the self-assembly process of microporous structures: syntheses and characterization of 12 new silver halide/thiocyanate supramolecular polymers

CrystEngComm ◽  
2012 ◽  
Vol 14 (9) ◽  
pp. 3241 ◽  
Author(s):  
Yong-Zhen Qiao ◽  
Wen-Zhen Fu ◽  
Jun-Ming Yue ◽  
Xiu-Cun Liu ◽  
Yun-Yin Niu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Silver Halide ◽  
The Self ◽  
Supramolecular Polymers ◽  
Assembly Process

Self-assembly of peptide amphiphiles for drug delivery: the role of peptide primary and secondary structures

2017 ◽  
Vol 5 (12) ◽  
pp. 2369-2380 ◽  
Author(s):  
Zhenhua Song ◽  
Xing Chen ◽  
Xinru You ◽  
Keqing Huang ◽  
Arvind Dhinakar ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Self Assembly ◽  
Secondary Structures ◽  
Peptide Amphiphiles ◽  
Alkyl Chains ◽  
Self Assembling

Peptide amphiphiles (PAs), functionalized with alkyl chains, are capable of self-assembling into various nanostructures.

Activation of cytochrome c to a peroxidase compound I-type intermediate by H2O2: relevance to redox signalling in apoptosis

2004 ◽  
Vol 71 ◽  
pp. 97-106 ◽  
Author(s):  
Mark Burkitt ◽  
Clare Jones ◽  
Andrew Lawrence ◽  
Peter Wardman
Keyword(s):  
Cytochrome C ◽  
Hydroxyl Radical ◽  
Redox Regulation ◽  
Chemotherapeutic Agents ◽  
Tyrosyl Radical ◽  
Compound I ◽  
Definitive Evidence ◽  
Enhanced Production ◽  
Physico Chemical

The release of cytochrome c from mitochondria during apoptosis results in the enhanced production of superoxide radicals, which are converted to H2O2 by Mn-superoxide dismutase. We have been concerned with the role of cytochrome c/H2O2 in the induction of oxidative stress during apoptosis. Our initial studies showed that cytochrome c is a potent catalyst of 2′,7′-dichlorofluorescin oxidation, thereby explaining the increased rate of production of the fluorophore 2′,7′-dichlorofluorescein in apoptotic cells. Although it has been speculated that the oxidizing species may be a ferryl-haem intermediate, no definitive evidence for the formation of such a species has been reported. Alternatively, it is possible that the hydroxyl radical may be generated, as seen in the reaction of certain iron chelates with H2O2. By examining the effects of radical scavengers on 2′,7′-dichlorofluorescin oxidation by cytochrome c/H2O2, together with complementary EPR studies, we have demonstrated that the hydroxyl radical is not generated. Our findings point, instead, to the formation of a peroxidase compound I species, with one oxidizing equivalent present as an oxo-ferryl haem intermediate and the other as the tyrosyl radical identified by Barr and colleagues [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503]. Studies with spin traps indicated that the oxo-ferryl haem is the active oxidant. These findings provide a physico-chemical basis for the redox changes that occur during apoptosis. Excessive changes (possibly catalysed by cytochrome c) may have implications for the redox regulation of cell death, including the sensitivity of tumour cells to chemotherapeutic agents.

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

Adiabatic large polarons in anisotropic molecular crystals

2011 ◽  
Vol 35 (1) ◽  
pp. 15-27
Author(s):  
Zoran Ivić ◽  
Željko Pržulj
Keyword(s):  
Energy Transfer ◽  
Effective Mass ◽  
Molecular Crystals ◽  
Single Chain ◽  
Proper Understanding ◽  
One Dimensional ◽  
Interchain Coupling ◽  
Large Polaron ◽  
The One

Adiabatic large polarons in anisotropic molecular crystals We study the large polaron whose motion is confined to a single chain in a system composed of the collection of parallel molecular chains embedded in threedimensional lattice. It is found that the interchain coupling has a significant impact on the large polaron characteristics. In particular, its radius is quite larger while its effective mass is considerably lighter than that estimated within the one-dimensional models. We believe that our findings should be taken into account for the proper understanding of the possible role of large polarons in the charge and energy transfer in quasi-one-dimensional substances.

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