scholarly journals Probing the Enzymatic Activity of Individual Biocatalytic fd-Viral Particles by Electrochemical-Atomic Force Microscopy

ACS Catalysis ◽  
2020 ◽  
Vol 10 (14) ◽  
pp. 7843-7856
Author(s):  
Telmo O. Paiva ◽  
Kristian Torbensen ◽  
Anisha N. Patel ◽  
Agnès Anne ◽  
Arnaud Chovin ◽  
...  
2010 ◽  
Vol 56 (1) ◽  
pp. 26-39 ◽  
Author(s):  
A.L. Kaysheva ◽  
Yu.D. Ivanov ◽  
V.G. Zgoda ◽  
P.A. Frantsuzov ◽  
T.O. Pleshakova ◽  
...  

Possibility of detection and identification of hepatitis C viral particles with mass spectrometry (MS) in combination with atomic force microscopy (AFM) had been investigated. AFM/MS approach is based on two technologies: 1. AFM-biospecific fishing that allows to detect, concentrate from solution and to count protein complexes on a surface of AFM-nanochip; 2. mass spectrometric identification of these complexes. AFM-biospecific fishing of HCVcoreAg from solution was carried onto surface of AFM-nanochips with immobilized anti-HCVcoreAg. It was shown that HCVcoreAg/anti-HCVcoreim complexes were formed onto AFM-nanochips in quantity sufficient for mass spectrometric identification. Thus, AFM/MS approach allows to identify fragments of hepatitis C virus fished onto a surface of AFM-nanochip from serum.


2020 ◽  
Vol 10 (13) ◽  
pp. 4560 ◽  
Author(s):  
Yuri D. Ivanov ◽  
Tatyana O. Pleshakova ◽  
Ivan D. Shumov ◽  
Andrey F. Kozlov ◽  
Tatyana S. Romanova ◽  
...  

The influence of liquid motion in flow-based systems on the aggregation state of an enzyme and on its enzymatic activity was studied, with horseradish peroxidase (HRP) as an example. Our experiments were carried out in a setup modeling the flow section of the biosensor communication with a measuring cell containing a protein solution. Studies were conducted for a biosensor measuring cell located along the axis of a spiral-moving liquid flow. The aggregation state of the protein was determined with an atomic force microscopy-based sensor (AFM sensor). It has been demonstrated that upon flowing of water through silicone biosensor communications, an increased aggregation of HRP protein was observed, but, at the same time, its enzymatic activity did not change. Our results obtained herein are useful in the development of models describing the influence of liquid flow in biosensor communications on the properties of enzymes and other proteins. This is particularly important for the development of serologic protein biosensors, which are beginning to be used for the early diagnosis of oncological diseases (such as brain cancer, prostate cancer, breast cancer etc.). The results obtained herein should also be taken into account when considering possible changes in hemodynamics due to increased protein aggregation.


2013 ◽  
Vol 49 (30) ◽  
pp. 3113 ◽  
Author(s):  
Shlomit Guy ◽  
Dvir Rotem ◽  
Zvi Hayouka ◽  
Ronen Gabizon ◽  
Aviad Levin ◽  
...  

2018 ◽  
Author(s):  
Selma Dahmane ◽  
Christine Doucet ◽  
Antoine Le Gall ◽  
Célia Chamontin ◽  
Patrice Dosset ◽  
...  

SUMMARYHIV-1 assembly specifically alters both partitioning and dynamics of the tetraspanins CD9 and CD81 forming enriched areas where the virus buds. Importantly the presence of these proteins at exit sites and in viral particles inhibits virus-induced membrane fusion. To get molecular insights into tetraspanins partitioning in this viral context, we correlated nanoscale CD9 mapping obtained by super resolution microscopy to membrane topography probed by Atomic Force Microscopy (AFM). We demonstrated that CD9 is specifically trapped within the nascent viral particles, especially at buds tips, and that Gag mediate CD9 and CD81 depletion from cellular surfaces, even in the absence of Vpu and Nef, resulting from tetraspanins escaping from the plasma membrane during HIV-1 release. In addition, we showed that CD9 is organized as small membrane assemblies of few tens of nanometers that can coalesce upon Gag expression. Our results support a functional redundancy among tetraspanins during HIV release.


Author(s):  
A. L. Kaysheva ◽  
Yu. D. Ivanov ◽  
V. G. Zgoda ◽  
P. A. Frantsuzov ◽  
T. O. Pleshakova ◽  
...  

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