scholarly journals Computational Approach to study the effect of point mutations in the development of antifungal resistance to Azoles and Flucytosine Drugs in Candida auris

Author(s):  
Shreeya Mhade ◽  
Gursimran Kaur Uppal ◽  
Sanket Bapat

Background: Candida auris is associated with invasive and severe candidemia, multi-drug resistance and high mortalities. Azoles and Flucytosine are commonly used antifungal drugs. Lanosterol alpha-demethylase (ERG11), Uracil phosphoribosyl transferase (FUR1) are two principal proteins involved in ergosterol biosynthesis and pyrimidine metabolism. However, crystal structures of these proteins from C. auris have not yet been established. We constructed structural model of ERG11 and FUR1 proteins for South-African Clade using homology modelling, molecular docking and molecular dynamics simulations. To investigate how point mutations affect drug interaction, we used the same methods on ERG11 mutants (Y132F, K143R) and FUR1 mutants (F211I). Methodology: Homology modelling was used to construct 3D structure of proteins. Reliability of models was analysed by using validation tools. The drug interaction in wild and mutant variants was studied using molecular docking, and binding energy was calculated. Finally, we investigated structural significance of point-mutation between two variants of FUR1 through MD Simulation. Result: Structural models of ERG11 and FUR1 were compared based on binding energy and hydrogen bonding. Few azole compounds showed no effect of mutation on interaction. Further, it was found that binding affinity for 5-fluorocytosine decreases in the mutant variant of FUR1. MD Simulation of wild variant FUR1-5FC complex showed stabilisation till 7ns while mutated complex was stable for 4.5ns. Conclusion: C. auris resistance to antifungal drugs poses a significant risk to public health. The study sheds light on how drug interactions are influenced by mutations and aids in the development of antifungal drugs.

Author(s):  
Shola Elijah Adeniji

Introduction: Mycobacterium tuberculosis has instigated a serious challenge toward the effective treatment of tuberculosis. The reoccurrence of the resistant strains of the disease to accessible drugs/medications has mandate for the development of more effective anti-tubercular agents with efficient activities. Time expended and costs in discovering and synthesizing new hypothetical drugs with improved biological activity have been a major challenge toward the treatment of multi-drug resistance strain M. tuberculosis (TB). Meanwhile, to solve the problem stated, a new approach i.e. QSAR which establish connection between novel drugs with a better biological against M. tuberculosis is adopted. Methods: The anti-tubercular model established in this study to forecast the biological activities of some anti-tubercular compounds selected and to design new hypothetical drugs is subjective to the molecular descriptors; MATS7s, SM1_DzZ, SpMin4_Bhv, TDB3v and RDF70v. Ligand-receptor interactions between quinoline derivatives and the receptor (DNA gyrase) was carried out using molecular docking technique by employing the PyRx virtual screening software and discovery studio visualizer software. Furthermore, docking study indicates that compounds 20 of the derivatives with promising biological activity have the utmost binding energy of -17.79 kcal/mol. Results: Meanwhile, the interaction of the standard drug; isoniazid with the target enzyme was observed with the binding energy -14.6 kcal/mol which was significantly lesser than the binding energy of the ligand (compound 20).Therefore, compound 20 served as a template structure to designed compounds with more efficient activities. Among the compounds designed; compounds 20p was observed with better anti-tubercular activities with more prominent binding affinities of -24.3kcal/mol. Conclusion: The presumption of this research aid the medicinal chemists and pharmacist to design and synthesis a novel drug candidate against the tuberculosis. Moreover, in-vitro and in-vivo test could be carried out to validate the computational results.


2019 ◽  
Vol 13 ◽  
pp. 117793221986553 ◽  
Author(s):  
Gbolahan O Oduselu ◽  
Olayinka O Ajani ◽  
Yvonne U Ajamma ◽  
Benedikt Brors ◽  
Ezekiel Adebiyi

Plasmodium falciparum adenylosuccinate lyase ( PfADSL) is an important enzyme in purine metabolism. Although several benzimidazole derivatives have been commercially developed into drugs, the template design as inhibitor against PfADSL has not been fully explored. This study aims to model the 3-dimensional (3D) structure of PfADSL, design and predict in silico absorption, distribution, metabolism, excretion and toxicity (ADMET) of 8 substituted benzo[ d]imidazol-1-yl)methyl)benzimidamide compounds as well as predict the potential interaction modes and binding affinities of the designed ligands with the modelled PfADSL. PfADSL 3D structure was modelled using SWISS-MODEL, whereas the compounds were designed using ChemDraw Professional. ADMET predictions were done using OSIRIS Property Explorer and Swiss ADME, whereas molecular docking was done with AutoDock Tools. All designed compounds exhibited good in silico ADMET properties, hence can be considered safe for drug development. Binding energies ranged from −6.85 to −8.75 kcal/mol. Thus, they could be further synthesised and developed into active commercial antimalarial drugs.


2021 ◽  
Author(s):  
Gerson Nakazato ◽  
Wagner J Favaro ◽  
Guillermo R Castro ◽  
Nelson Duran

Candida auris, which is one of the causative agents of candidiasis, has been detected in several individuals with immune deficiency worldwide, mainly in different American countries, since 2012. C. auris infections are at risk of becoming epidemic because this species shows multi-drug resistance to several antifungal drugs available in the market; thus, since the current public health condition at global scale is threatened by the SARS-CoV-2 pandemic, C. auris infections could lead to high mortality rates. Different strategies, such as drug repurposing and the combination of antifungal drugs to other biocide molecules, were developed. However, they are time-limited strategies since drug resistance has increased due to C. auris pathologies. As an alternative, the recent development of nanotechnological devices has opened room for the efficient treatment of C. auris infections. Most specifically, the biocide effect of nanoparticles combined to/capped with antifungal drugs in different platforms seems to be an affordable technology to stop invasive C. auris infections.


2020 ◽  
Author(s):  
Dr. Mustafa Alhaji Isa

<p>Shikimate kinase (SK) is an enzyme that catalyzes the fifth steps in the shikimate pathway. The enzyme facilitate the transfer of phosphoryl from ATP to shikimate, to produce ADP and shikimate-3-phosphate from <i>Mycobacterium tuberculosis</i> (MTB). The 3D structure of SK bound ligands (4-(2-Hydroxyethyl)-1-Piperazine Ethanesulfonic Acid (EPE)), ADP and metals (Mg2+, Cl- and Pt+) obtained from PDB (PDB ID: 1L4U and resolution 1.8Å). The structural analysis of the SK revealed that it has a substrate or shikimate binding site (Asp34, Arg58, and Lys136) and substrate binding via amide nitrogen (Gly80). It also possessed nucleotide binding region (Gly12─Thr17), the ATP binding site (Arg117 and Arg153) and metallic ion (Mg2+) binding site (Ser16 and Asp32). All these residues mentioned above play an essential role in the catalytic activity of the SK. Therefore inhibition any of these residues serve as a stumbling block for the normal function of the enzyme. A total of eleven thousand three hundred and twenty-three (11323) compounds obtained from two public databases (Zinc Database and PubChem) capable of binding to SK with good binding affinities. These compounds further filtered for Lipinski’s rule of five, drug-likeness, molecular docking analysis, and ADME and toxicity analysis. Three compounds with minimum binding energies─ PubChem15478 (─11.75 kcal/mol), ZINC02838601 (─11.52 kcal/mol), and ZINC11790367 (─9.88 kcal/mol) ─were selected and used for the MD simulation analysis. Also, MD simulation of the SK bound to EPE, ADP, and Mg2+ were carried out to compare their stabilities with the selected protein-ligand complexes. The result showed that the two compounds (ZINC11790367 and PubChem15478) formed stable and rigid complexes comparable to the bound ligand and the cofactors during the 50ns MD simulation. Therefore, it concluded that the above mentioned two compounds capable of inhibiting SK considered as prospective drugs for MTB after successful experimental validation.</p>


2020 ◽  
Author(s):  
Dr. Mustafa Alhaji Isa

<p>Shikimate kinase (SK) is an enzyme that catalyzes the fifth steps in the shikimate pathway. The enzyme facilitate the transfer of phosphoryl from ATP to shikimate, to produce ADP and shikimate-3-phosphate from <i>Mycobacterium tuberculosis</i> (MTB). The 3D structure of SK bound ligands (4-(2-Hydroxyethyl)-1-Piperazine Ethanesulfonic Acid (EPE)), ADP and metals (Mg2+, Cl- and Pt+) obtained from PDB (PDB ID: 1L4U and resolution 1.8Å). The structural analysis of the SK revealed that it has a substrate or shikimate binding site (Asp34, Arg58, and Lys136) and substrate binding via amide nitrogen (Gly80). It also possessed nucleotide binding region (Gly12─Thr17), the ATP binding site (Arg117 and Arg153) and metallic ion (Mg2+) binding site (Ser16 and Asp32). All these residues mentioned above play an essential role in the catalytic activity of the SK. Therefore inhibition any of these residues serve as a stumbling block for the normal function of the enzyme. A total of eleven thousand three hundred and twenty-three (11323) compounds obtained from two public databases (Zinc Database and PubChem) capable of binding to SK with good binding affinities. These compounds further filtered for Lipinski’s rule of five, drug-likeness, molecular docking analysis, and ADME and toxicity analysis. Three compounds with minimum binding energies─ PubChem15478 (─11.75 kcal/mol), ZINC02838601 (─11.52 kcal/mol), and ZINC11790367 (─9.88 kcal/mol) ─were selected and used for the MD simulation analysis. Also, MD simulation of the SK bound to EPE, ADP, and Mg2+ were carried out to compare their stabilities with the selected protein-ligand complexes. The result showed that the two compounds (ZINC11790367 and PubChem15478) formed stable and rigid complexes comparable to the bound ligand and the cofactors during the 50ns MD simulation. Therefore, it concluded that the above mentioned two compounds capable of inhibiting SK considered as prospective drugs for MTB after successful experimental validation.</p>


Author(s):  
Divya Shaji

Aims: To identify natural inhibitors against MCT8 for Allan-Herndon-Dudley Syndrome. Background: Monocarboxylate transporter 8 (MCT8) is a Thyroid hormone (TH) transporter which is highly expressed in liver and brain. Mutations in the MCT8 gene (SLC16A2) cause a syndrome of psychomotor retardation in humans, known as Allan–Herndon–Dudley syndrome (AHDS). Currently, no treatment is available for AHDS. Therefore, there is a need to discover new inhibitors of MCT8 for treating AHDS. Objective: Considering the importance of natural compounds in drug discovery, this study aimed to identify potential natural inhibitors against MCT8. Method: As Protein-ligand interactions play a key role in structure based drug design, this study screened 24 natural kinase inhibitors and investigated their binding affinity against MCT8 by using molecular docking. The modelled 3D structure of MCT8 docked with 24 compounds using PyRX through Autodock Vina. Drug-likeness studies were made using Swiss ADME and Lipinski’s rule of five was performed. TRIAC, Desipramine and Silychristin were used as the positive controls. Binding energies of the selected compounds were compared with that of positive controls. Result: The results showed that Emodin exhibited best binding energy of −8.6 kcal/mol followed by Helenaquinol, Cercosporamide and Resveratrol. Moreover, it was observed that Emodin and Helenaquinol exhibit higher binding energy than the positive controls. Cercosporamide and Resveratrol exhibited higher binding energy than Triac and Desipramine and showed the binding energy similar to Silychristin. Conclusion: This study reveals that these compounds could be promising candidates for further evaluation for AHDS prevention.


2018 ◽  
Vol 2 (1) ◽  
pp. 1-5
Author(s):  
Noorul Aini Sulaiman ◽  

Protease is an enzyme that catalysed the hydrolysis of protein into peptide. Application of protease in industry has been linked with cost effective substrates and complex of enzyme-substrate stability. Molecular docking approach has identified casein as a preference substrates. However, lack of data on casein mode of binding to protease and enzyme stability represents a limitation for its production and structural optimization. In this study, we have used a molecular dynamic (MD) to examine the stability of complex enzyme-substrate of protease from Bacillus lehensis G1. The 3D structure of protease (BleG1_1979) was docked with substrate casein using AutoDock Vina. Structural analysis of the substrate-binding cleft revealed a binding site of casein was predominantly at the hydrophobic region of BleG1_1979. The MD of complex BleG1_1979-casein was tested with two temperatures; 298 K and 310 K using GROMACS v5.1.4. MD simulation showed a stable behaviour of BleG1_1979 over the 20 ns simulation period. The molecular docking and MD simulation suggested that the production of protease from B. lehensis G1 by utilization of casein and the stability of complex protease-casein could be a potential application to generate a cost effective enzyme to be develop for industrial use.


2020 ◽  
Author(s):  
Sahar Qazi ◽  
Mustafa Alhaji Isa ◽  
Adam Mustapha ◽  
Khalid Raza ◽  
Ibrahim Alkali Allamin ◽  
...  

<p>The Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) is an infectious virus that causes mild to severe life-threatening upper respiratory tract infection. The virus emerged in Wuhan, China in 2019, and later spread across the globe. Its genome has been completely sequenced and based on the genomic information, the virus possessed 3C-Like Main Protease (3CLpro), an essential multifunctional enzyme that plays a vital role in the replication and transcription of the virus by cleaving polyprotein at eleven various sites to produce different non-structural proteins. This makes the protein an important target for drug design and discovery. Herein, we analyzed the interaction between the 3CLpro and potential inhibitory compounds identified from the extracts of <i>Zingiber offinale</i> and <i>Anacardium occidentale</i> using in silico docking and Molecular Dynamics (MD) Simulation. The crystal structure of SARS-CoV-2 main protease in complex with 02J (5-Methylisoxazole-3-carboxylic acid) and PEJ (composite ligand) (PDB Code: 6LU7,2.16Å) retrieved from Protein Data Bank (PDB) and subject to structure optimization and energy minimization. A total of twenty-nine compounds were obtained from the extracts of <i>Zingiber offinale </i>and the leaves of <i>Anacardium occidentale. </i>These compounds were screened for physicochemical (Lipinski rule of five, Veber rule, and Egan filter), <i>Pan</i>-Assay Interference Structure (PAINS), and pharmacokinetic properties to determine the Pharmaceutical Active Ingredients (PAIs). Of the 29 compounds, only nineteen (19) possessed drug-likeness properties with efficient oral bioavailability and less toxicity. These compounds subjected to molecular docking analysis to determine their binding energies with the 3CLpro. The result of the analysis indicated that the free binding energies of the compounds ranged between ˗5.08 and -10.24kcal/mol, better than the binding energies of 02j (-4.10kcal/mol) and PJE (-5.07kcal.mol). Six compounds (CID_99615 = -10.24kcal/mol, CID_3981360 = 9.75kcal/mol, CID_9910474 = -9.14kcal/mol, CID_11697907 = -9.10kcal/mol, CID_10503282 = -9.09kcal/mol and CID_620012 = -8.53kcal/mol) with good binding energies further selected and subjected to MD Simulation to determine the stability of the protein-ligand complex. The results of the analysis indicated that all the ligands form stable complexes with the protein, although, CID_9910474 and CID_10503282 had a better stability when compared to other selected phytochemicals (CID_99615, CID_3981360, CID_620012, and CID_11697907). </p>


2020 ◽  
Author(s):  
Sahar Qazi ◽  
Mustafa Alhaji Isa ◽  
Adam Mustapha ◽  
Khalid Raza ◽  
Ibrahim Alkali Allamin ◽  
...  

<p>The Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) is an infectious virus that causes mild to severe life-threatening upper respiratory tract infection. The virus emerged in Wuhan, China in 2019, and later spread across the globe. Its genome has been completely sequenced and based on the genomic information, the virus possessed 3C-Like Main Protease (3CLpro), an essential multifunctional enzyme that plays a vital role in the replication and transcription of the virus by cleaving polyprotein at eleven various sites to produce different non-structural proteins. This makes the protein an important target for drug design and discovery. Herein, we analyzed the interaction between the 3CLpro and potential inhibitory compounds identified from the extracts of <i>Zingiber offinale</i> and <i>Anacardium occidentale</i> using in silico docking and Molecular Dynamics (MD) Simulation. The crystal structure of SARS-CoV-2 main protease in complex with 02J (5-Methylisoxazole-3-carboxylic acid) and PEJ (composite ligand) (PDB Code: 6LU7,2.16Å) retrieved from Protein Data Bank (PDB) and subject to structure optimization and energy minimization. A total of twenty-nine compounds were obtained from the extracts of <i>Zingiber offinale </i>and the leaves of <i>Anacardium occidentale. </i>These compounds were screened for physicochemical (Lipinski rule of five, Veber rule, and Egan filter), <i>Pan</i>-Assay Interference Structure (PAINS), and pharmacokinetic properties to determine the Pharmaceutical Active Ingredients (PAIs). Of the 29 compounds, only nineteen (19) possessed drug-likeness properties with efficient oral bioavailability and less toxicity. These compounds subjected to molecular docking analysis to determine their binding energies with the 3CLpro. The result of the analysis indicated that the free binding energies of the compounds ranged between ˗5.08 and -10.24kcal/mol, better than the binding energies of 02j (-4.10kcal/mol) and PJE (-5.07kcal.mol). Six compounds (CID_99615 = -10.24kcal/mol, CID_3981360 = 9.75kcal/mol, CID_9910474 = -9.14kcal/mol, CID_11697907 = -9.10kcal/mol, CID_10503282 = -9.09kcal/mol and CID_620012 = -8.53kcal/mol) with good binding energies further selected and subjected to MD Simulation to determine the stability of the protein-ligand complex. The results of the analysis indicated that all the ligands form stable complexes with the protein, although, CID_9910474 and CID_10503282 had a better stability when compared to other selected phytochemicals (CID_99615, CID_3981360, CID_620012, and CID_11697907). </p>


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