scholarly journals Understanding the Molecular-Level Interactions of Glucosamine-Glycerol Assemblies: A Model System for Chitosan Plasticization

ACS Omega ◽  
2021 ◽  
Author(s):  
Danielle R. Smith ◽  
Austin P. Escobar ◽  
Melissa N. Andris ◽  
Brycelyn M. Boardman ◽  
Gretchen M. Peters
Keyword(s):  
Molecular Level ◽  
Model System

scholarly journals Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols

2015 ◽  
Vol 11 ◽  
pp. 828-836 ◽  
Author(s):  
Stefanie Krysiak ◽  
Qiang Wei ◽  
Klaus Rischka ◽  
Andreas Hartwig ◽  
Rainer Haag ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Molecular Level ◽  
Model System ◽  
Surface Coatings ◽  
Adhesive Bonds ◽  
Force Microscopy ◽  
Atomic Force ◽  
Aqueous Environments ◽  
End Groups ◽  
Catechol Group

Nature often serves as a model system for developing new adhesives. In aqueous environments, mussel-inspired adhesives are promising candidates. Understanding the mechanism of the extraordinarily strong adhesive bonds of the catechol group will likely aid in the development of adhesives. With this aim, we study the adhesion of catechol-based adhesives to metal oxides on the molecular level using atomic force microscopy (AFM). The comparison of single catechols (dopamine) with multiple catechols on hyperbranched polyglycerols (hPG) at various pH and dwell times allowed us to further increase our understanding. In particular, we were able to elucidate how to achieve strong bonds of different valency. It was concluded that hyperbranched polyglycerols with added catechol end groups are promising candidates for durable surface coatings.

Organic Cocrystal Photovoltaic Behavior: A Model System to Study Charge Recombination of C60and C70at the Molecular Level

2016 ◽  
Vol 2 (6) ◽  
pp. 1500423 ◽  
Author(s):  
Hantang Zhang ◽  
Lang Jiang ◽  
Yonggang Zhen ◽  
Jing Zhang ◽  
Guangchao Han ◽  
...  
Keyword(s):  
Molecular Level ◽  
Model System ◽  
Charge Recombination ◽  
Photovoltaic Behavior

scholarly journals Robust manipulation of the behavior of Drosophila melanogaster by a fungal pathogen in the laboratory

2017 ◽  
Author(s):  
Carolyn Elya ◽  
Tin Ching Lok ◽  
Quinn E. Spencer ◽  
Hayley McCausland ◽  
Ciera C. Martinez ◽  
...  
Keyword(s):  
Fungal Pathogen ◽  
Molecular Level ◽  
Model System ◽  
Behavioral Changes ◽  
Rapid Progress ◽  
Entomophthora Muscae ◽  
Animal Hosts ◽  
Mechanistic Basis ◽  
Molecular Manipulation ◽  
New System

AbstractMany microbes induce striking behavioral changes in their animal hosts, but how they achieve this is poorly understood, especially at the molecular level. Mechanistic understanding has been largely constrained by the lack of a model system with advanced tools for molecular manipulation. We recently discovered a strain of the behavior-manipulating fungal pathogen Entomophthora muscae infecting wild Drosophila, and established methods to infect D. melanogaster in the lab. Lab-infected flies manifest the moribund behaviors characteristic of E. muscae infection: hours before death, they climb upward, extend their proboscides and affix in place, then raise their wings, clearing a path for infectious spores to launch from their abdomens. We found that E. muscae invades the fly nervous system, suggesting a direct means by which the fungus could induce behavioral changes. Given the vast molecular toolkit available for D. melanogaster, we believe this new system will enable rapid progress in understanding the mechanistic basis of E. muscae’s behavioral manipulation in the fly.

Quantitative analysis at the molecular level of laser/neural tissue interactions using a liposome model system

1991 ◽  
Author(s):  
David L. VanderMeulen ◽  
Prabhakar Misra ◽  
Jason Michael ◽  
Kenneth G. Spears ◽  
Mustafa Khoka
Keyword(s):  
Quantitative Analysis ◽  
Molecular Level ◽  
Neural Tissue ◽  
Model System ◽  
Tissue Interactions

scholarly journals MODULATION OF OXIDATIVE STRESS BY ABHRAK BHASMA IN DROSOPHILA MELANOGASTER

2018 ◽  
Vol 11 (5) ◽  
pp. 247
Author(s):  
Rambhadur P Subedi ◽  
Rekha R Vartak ◽  
Purushottam G Kale
Keyword(s):  
Drosophila Melanogaster ◽  
Molecular Level ◽  
Reduced Glutathione ◽  
Radical Scavenging ◽  
Model System ◽  
Free Radical Scavenging ◽  
Regenerative Therapy ◽  
Radical Scavenging Capacity ◽  
Scavenging Capacity ◽  
Antioxidant Machinery

 Objective: Management of aging is one of the most actively researched areas in biology. Ayurvedic preparations such as Abhrak Bhasma (AB) have been used for improving longevity and regenerative therapy as well as in treating various ailments. Modes of action of such Ayurvedic preparations are poorly understood at molecular level. Current investigation tests the efficacy of AB in modulating various parameters linked to oxidative stress.Methods: Drosophila melanogaster was used as a model system to test the efficacy of AB in inducing antioxidant machinery. Drosophila flies were fed on diet supplemented with AB at larval and adult stages. Subsequently, various parameters, catalytic as well as non-catalytic, related to antioxidant machinery were analyzed.Results: AB has been found to modulate the activity of superoxide dismutase and catalase enzymes as well as the total reduced glutathione (GSH) content. Larvae and adults feeding on diet supplemented with AB exhibit significantly lower levels of total GSH content (decrease of about 40–70% for larvae, while 31–36% for adults) and without any conclusive effect on GSH:oxidized glutathione ratio, free radical scavenging capacity, and extent of lipid peroxidation. These larvae and adults fed on diet supplemented with AB also exhibited an increase in the level of transcription of cap “n” collar C, heat shock protein 70, and catalase genes (≥1.5 fold, except in few cases).Conclusion: Overall, AB alters various parameters linked to antioxidant machinery in D. melanogaster. The induced components may provide protection to the organism during stressful conditions.

scholarly journals Unifying the Ambivalent Mechanisms of Protein-Stabilising Osmolytes

2020 ◽  
Author(s):  
Mrinmoy Mukherjee ◽  
Jagannath Mondal
Keyword(s):  
Conformational Equilibrium ◽  
Molecular Level ◽  
Model System ◽  
Protein Stabilization ◽  
Interaction Theory ◽  
Protein Surface ◽  
Preferential Binding ◽  
Energy Simulations ◽  
Trimethyl Amine ◽  
Recurrent Motif

AbstractThe mechanism of protein stabilization by zwiterionic osmolytes has remained a long-standing puzzle. While the prevalent mechanistic hypothesis suggests an ‘osmo-phobic’ model in which osmolytes are assumed to stabilize proteins by preferentially excluding themselves from the protein surface, emerging evidences of preferential binding of popular osmolyte trimethyl amine N-oxide (TMAO) with hydrophobic macromolecules contradict this view. Here we address these contrasting perspectives by investigating the folding mechanism of a set of mini proteins in aqueous solutions of two different osmolytes glycine and TMAO, via free energy simulations. Our results demonstrate that, while both osmolytes are found to stabilize the folded conformation of the mini proteins, their mechanism of actions are mutually diverse: Specifically, glycine always depletes from the surface of all mini proteins, thereby conforming to the osmophobic model; but TMAO is found to display ambivalent signatures of protein-specific preferential binding and exclusion to/from the protein surface. At molecular level, the presence of an extended hydrophobic patch in protein topology is found to be recurrent motif in proteins leading to favorable binding with TMAO. Finally, an analysis based upon the preferential interaction theory and folding free energetics reveals that irrespective of preferential binding vs exclusion of osmolytes, it is the relative preferential depletion of osmolytes on transition from folded to unfolded conformation of proteins, which drives the overall conformational equilibrium towards the folded state in presence of osmolytes. Taken together, moving beyond the model system and hypothesis, this work brings out ambivalent mechanism of osmolytes on proteins and provides an unifying justification.

Preparatory Procedures for Electron Microscopic Analysis at the Molecular Level of Resolution

1978 ◽  
Vol 36 (3) ◽  
pp. 516-520
Author(s):  
F.J. Sjostrand
Keyword(s):  
Electron Microscope ◽  
Molecular Level ◽  
Microscopic Analysis ◽  
Resolving Power ◽  
Cellular Structures ◽  
Electron Microscopic ◽  
Systematic Analysis ◽  
Technical Developments ◽  
Thin Sectioning ◽  
Obvious Reason

In the 1940's and 1950's electron microscopy conferences were attended with everybody interested in learning about the latest technical developments for one very obvious reason. There was the electron microscope with its outstanding performance but nobody could make very much use of it because we were lacking proper techniques to prepare biological specimens. The development of the thin sectioning technique with its perfectioning in 1952 changed the situation and systematic analysis of the structure of cells could now be pursued. Since then electron microscopists have in general become satisfied with the level of resolution at which cellular structures can be analyzed when applying this technique. There has been little interest in trying to push the limit of resolution closer to that determined by the resolving power of the electron microscope.

A Protozoan Model for Golgi-Associated Calcification

1971 ◽  
Vol 29 ◽  
pp. 332-333
Author(s):  
D. C. Williams ◽  
D. E. Outka
Keyword(s):  
Golgi Apparatus ◽  
Organic Matrix ◽  
Model System ◽  
Sequential Formation

Many studies have shown that the Golgi apparatus is involved in a variety of synthetic activities, and probably no Golgi product is more elaborate than the scales produced by various kinds of phytoflagellates. The formation of calcified scales (coccoliths, Fig. 1,2) of the coccolithophorid phytoflagellates provides a particularly interesting model system for the study of biological mineralization, and the sequential formation of Golgi products.The coccoliths of Hymenomonas carterae consist of a scale-like base (Fig. 2 and 4, b) with a highly structured calcified (CaCO3) rim composed of two distinct elements which alternate about the base periphery (Fig. 1 and 3, A, B). Each element is enveloped by a sheath-like organic matrix (Fig. 3; Fig. 4, m).

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