Travelers' Diarrhea-Associated Enterotoxigenic Escherichia coli gyrA Mutants and Quinolone Antibiotic Affinity: A Molecular Dynamics Simulation and Residue Interaction Network Analysis

2016 ◽  
Vol 20 (11) ◽  
pp. 635-644 ◽  
Author(s):  
Kusum Mehla ◽  
Jayashree Ramana
Keyword(s):  
Escherichia Coli ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Network Analysis ◽  
Interaction Network ◽  
Dynamics Simulation ◽  
Enterotoxigenic Escherichia Coli ◽  
Residue Interaction

scholarly journals Ketoamide Resistance and Hepatitis C Virus Fitness in Val55 Variants of the NS3 Serine Protease

2012 ◽  
Vol 56 (4) ◽  
pp. 1907-1915 ◽  
Author(s):  
Christoph Welsch ◽  
Sabine Schweizer ◽  
Tetsuro Shimakami ◽  
Francisco S. Domingues ◽  
Seungtaek Kim ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Molecular Mechanisms ◽  
Interaction Network ◽  
Rna Replication ◽  
Viral Fitness ◽  
Dynamics Simulation ◽  
Structural Flexibility ◽  
Residue Interaction

ABSTRACTDrug-resistant viral variants are a major issue in the use of direct-acting antiviral agents in chronic hepatitis C. Ketoamides are potent inhibitors of the NS3 protease, with V55A identified as mutation associated with resistance to boceprevir. Underlying molecular mechanisms are only partially understood. We applied a comprehensive sequence analysis to characterize the natural variability at Val55 within dominant worldwide patient strains. A residue-interaction network and molecular dynamics simulation were applied to identify mechanisms for ketoamide resistance and viral fitness in Val55 variants. An infectious H77S.3 cell culture system was used for variant phenotype characterization. We measured antiviral 50% effective concentration (EC50) and fold changes, as well as RNA replication and infectious virus yields from viral RNAs containing variants. Val55 was found highly conserved throughout all hepatitis C virus (HCV) genotypes. The conservative V55A and V55I variants were identified from HCV genotype 1a strains with no variants in genotype 1b. Topology measures from a residue-interaction network of the protease structure suggest a potential Val55 key role for modulation of molecular changes in the protease ligand-binding site. Molecular dynamics showed variants with constricted binding pockets and a loss of H-bonded interactions upon boceprevir binding to the variant proteases. These effects might explain low-level boceprevir resistance in the V55A variant, as well as the Val55 variant, reduced RNA replication capacity. Higher structural flexibility was found in the wild-type protease, whereas variants showed lower flexibility. Reduced structural flexibility could impact the Val55 variant's ability to adapt for NS3 domain-domain interaction and might explain the virus yield drop observed in variant strains.

scholarly journals The Potential role of Procyanidin as a Therapeutic Agent against SARS-CoV-2: A Text Mining, Molecular Docking and Molecular Dynamics Simulation Approach

2020 ◽  
Author(s):  
Nikhil Maroli ◽  
Balu Bhasuran ◽  
Jeyakumar Natarajan ◽  
Ponmalai Kolandaivel
Keyword(s):  
Molecular Dynamics ◽  
Molecular Docking ◽  
Molecular Dynamics Simulation ◽  
Text Mining ◽  
Van Der Waals ◽  
Interaction Network ◽  
Van Der Waals Interactions ◽  
Entity Recognition ◽  
Dynamics Simulation ◽  
Inhibition Mechanism

<p></p><p></p><p>A novel coronavirus (SARS-CoV-2) has caused a major outbreak in human all over the world. There are several proteins interplay during the entry and replication of this virus in human. Here, we have used text mining and named entity recognition method to identify co-occurrence of the important COVID 19 genes/proteins in the interaction network based on the frequency of the interaction. Network analysis revealed a set of genes/proteins, highly dense genes/protein clusters and sub-networks of Angiotensin-converting enzyme 2 (ACE2), Helicase, spike (S) protein (trimeric), membrane (M) protein, envelop (E) protein, and the nucleocapsid (N) protein. The isolated proteins are screened against procyanidin-a flavonoid from plants using molecular docking. Further, molecular dynamics simulation of critical proteins such as ACE2, Mpro and spike proteins are performed to elucidate the inhibition mechanism. The strong network of hydrogen bonds and hydrophobic interactions along with van der Waals interactions inhibit receptors, which are essential to the entry and replication of the SARS-CoV-2. The binding energy which largely arises from van der Waals interactions is calculated (ACE2=-50.21 ± 6.3, Mpro=-89.50 ± 6.32 and spike=-23.06 ± 4.39) through molecular mechanics Poisson-Boltzmann surface area also confirm the affinity of procyanidin towards the critical receptors.</p><p></p><p></p>

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