scholarly journals Structural Modifications Controlling Membrane Raft Partitioning and Curvature in Human and Viral Proteins

2020 ◽  
Vol 124 (35) ◽  
pp. 7574-7585
Author(s):  
Deniz Yurtsever ◽  
Joseph Helmuth Lorent

Protein-RNA interactions play a key role in the structure, morphogenesis and function of various systems (viruses, ribosomes and, more generally, protein synthesis). The neutron is a powerful tool to study those interactions. Some examples, are given. For viruses, neutrons provide structural information on the two molecules where they interact. Viral proteins do not appear to be simple globular proteins. In the interactions between tRNA and aminoacyl tRNA synthetases, neutrons allow a simultaneous study of the reaction and of the structural modifications associated with that reaction, giving a hint on the role of both electrostatic and specific interactions.


Author(s):  
J. Metz ◽  
M. Merlo ◽  
W. G. Forssmann

Structure and function of intercellular junctions were studied under the electronmicroscope using conventional thin sectioning and freeze-etch replicas. Alterations of tight and gap junctions were analyzed 1. of exocrine pancreatic cells under cell isolation conditions and pancreatic duct ligation and 2. of hepatocytes during extrahepatic cholestasis.During the different steps of cell isolation of exocrine pancreatic cells, gradual changes of tight and gap junctions were observed. Tight junctions, which formed belt-like structures around the apex of control acinar cells in situ, subsequently diminished, became interrupted and were concentrated into macular areas (Fig. 1). Aggregations of membrane associated particles, which looked similar to gap junctions, were intermixed within tight junctional areas (Fig. 1). These structures continously disappeared in the last stages of the isolation procedure. The intercellular junctions were finally separated without destroying the integrity of the cell membrane, which was confirmed with porcion yellow, lanthanum chloride and horse radish peroxidase.


2018 ◽  
Vol 69 (2) ◽  
pp. 328-331
Author(s):  
Irina Gradinaru ◽  
Leonard Ignat ◽  
Cristina Gena Dascalu ◽  
Laurentiu Valentin Soroaga ◽  
Magda Ecaterina Antohe

The aim of this study was represented by the definition and testing of a new formulation strategy and the functionality of composite materials, while ensuring the optimization of the relevant properties for the dental restoration processes through the use of precise techniques of characterization, the modification and functionality of the components in view of obtaining results that are characterized by an optimum biomechanical and bioactive relation, in full agreement with the particularities of the dental structure that requires restoration. In view of obtaining new resistant composite structures we made a number of 10 samples including extracted teeth with various losses of dental substance and the structural modifications included 3 types of composites, whose structure was improved by the introduction of inorganic fillings based on hydroxyapatite and silver nanoparticles. All these structures were reinforced with two types of fibers, Reforpost fiber glass kit (Angelus) and Fiber post Schulzer Pre-silanized; With regard to the use of composite structures improved by HA addition, we notice a slight lacunary structure on the SEM images due to the properties of HA, an aspect present at much smaller dimensions in the silver � HA mix. The size of the grains associated with their continuous uniformity and adherence for the fibrillar structure stands out at the samples with hydroxyapatite, the first place as uniformity and adherence going to the composite of the nanofiller technology category.


2018 ◽  
Vol 25 (21) ◽  
pp. 2503-2519 ◽  
Author(s):  
Anne Kokel ◽  
Marianna Torok

Background: Since the first isolation of antimicrobial peptides (AMPs) they have attracted extensive interest in medicinal chemistry. However, only a few AMP-based drugs are currently available on the market. Despite their effectiveness, biodegradability, and versatile mode of action that is less likely to induce resistance compared to conventional antibiotics, AMPs suffer from major issues that need to be addressed to broaden their use. Notably, AMPs can lack selectivity leading to side effects and cytotoxicity, and also exhibit in vivo instability. Several strategies are being actively considered to overcome the limitations that restrain the success of AMPs. Methods: In the current work, recent strategies reported for improving AMPs in the context of drug design and delivery were surveyed, and also their possible impact on patients and the environment was assessed. Results: As a major advantage AMPs possess an easily tunable skeleton offering opportunities to improve their properties. Strategic structural modifications and the beneficial properties of cyclic or branched AMPs in term of stability have been reported. The conjugation of AMPs with nanoparticles has also been explored to increase their in vivo stability. Other techniques such as the coupling of AMPs with specific antibodies aim to increase the selectivity of the potential drug towards the target. These strategies were evaluated for their effect on the environment highlighting green technologies. Conclusion: Although further research is needed taking into account both environmental and human health consequences of novel AMPs, several of these compounds are promising drug candidates for use in sustainable medicine.


2020 ◽  
Vol 20 (18) ◽  
pp. 1900-1907
Author(s):  
Kasturi Sarkar ◽  
Parames C. Sil ◽  
Seyed Fazel Nabavi ◽  
Ioana Berindan-Neagoe ◽  
Cosmin Andrei Cismaru ◽  
...  

The global spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that causes COVID-19 has become a source of grave medical and socioeconomic concern to human society. Since its first appearance in the Wuhan region of China in December 2019, the most effective measures of managing the spread of SARS-CoV-2 infection have been social distancing and lockdown of human activity; the level of which has not been seen in our generations. Effective control of the viral infection and COVID-19 will ultimately depend on the development of either a vaccine or therapeutic agents. This article highlights the progresses made so far in these strategies by assessing key targets associated with the viral replication cycle. The key viral proteins and enzymes that could be targeted by new and repurposed drugs are discussed.


2009 ◽  
Vol 5 (2) ◽  
pp. 182-190 ◽  
Author(s):  
Julien Bourdron ◽  
Pascale Barbier ◽  
Diane Allegro ◽  
Claude Villard ◽  
Daniel Lafitte ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document