scholarly journals Glycan Epitopes and Potential Glycoside Antagonists of DC-SIGN Involved in COVID-19: In Silico Study

Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1586
Author(s):  
Meina Gao ◽  
Hui Li ◽  
Chenghao Ye ◽  
Kaixian Chen ◽  
Hualiang Jiang ◽  
...  
Keyword(s):  
In Silico ◽  
Systemic Infection ◽  
Intercellular Adhesion Molecule ◽  
Post Translational Modification ◽  
Sign Recognition ◽  
In Silico Study ◽  
Core Site ◽  
Dynamics Simulations ◽  
Antigen Presenting ◽  
Saikosaponin A

Glycosylation is an important post-translational modification that affects a wide variety of physiological functions. DC-SIGN (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin) is a protein expressed in antigen-presenting cells that recognizes a variety of glycan epitopes. Until now, the binding of DC-SIGN to SARS-CoV-2 Spike glycoprotein has been reported in various articles and is regarded to be a factor in systemic infection and cytokine storm. The mechanism of DC-SIGN recognition offers an alternative method for discovering new medication for COVID-19 treatment. Here, we discovered three potential pockets that hold different glycan epitopes by performing molecular dynamics simulations of previously reported oligosaccharides. The “EPN” motif, “NDD” motif, and Glu354 form the most critical pocket, which is known as the Core site. We proposed that the type of glycan epitopes, rather than the precise amino acid sequence, determines the recognition. Furthermore, we deduced that oligosaccharides could occupy an additional site, which adds to their higher affinity than monosaccharides. Based on our findings and previously described glycoforms on the SARS-CoV-2 Spike, we predicted the potential glycan epitopes for DC-SIGN. It suggested that glycan epitopes could be recognized at multiple sites, not just Asn234, Asn149 and Asn343. Subsequently, we found that Saikosaponin A and Liquiritin, two plant glycosides, were promising DC-SIGN antagonists in silico.

scholarly journals In-silico study of antituberculous activity of Zn-pyrazinamide in pyrazinamidase

2020 ◽  
Author(s):  
Jesus Antonio Alvarado-Huayhuaz ◽  
Wilmar Puma-Zamora ◽  
Ana Cecilia Valderrama-Negrón
Keyword(s):  
In Silico ◽  
Chemical Reactivity ◽  
Experimental Studies ◽  
New Drugs ◽  
In Silico Study ◽  
Three Stages ◽  
Dynamics Simulations ◽  
Antituberculous Activity ◽  
Tuberculosis Activity ◽  
Pyrazinoic Acid

Tuberculosis is caused by Mycobacterium tuberculosis and is one of the leading causes of death. Treatment with pyrazinamide depends on the formation of the bioactive species, pyrazinoic acid (POA), catalyzed by the enzyme pyrazinamidase (PZAse). New mutant strains show resistance to PZA, therefore, it is necessary to search for new drugs. Metallodrugs can offer a synergistic effect on the biological activity of the metal and the drug. Recent studies by our group show anti-tuberculosis activity of pyrazinamide coordinated with Zn, however, the mechanism of action is unknown. In this work, an in-silico study was carried out in three stages: Quantum mechanical, molecular docking and molecular dynamics simulations. ZnPZA (Egap = 4.12 eV) presented greater chemical reactivity than PZA (Egap = 4.97 eV). Greater binding energy was found in ZnPZA-PZAse (-6.98 kcal/mol) than in PZA-PZAse (-6.48 kcal/mol). RMSD and RMSF show stability in PZA-PZAse and ZnPZA-PZAse dockings. Hydrogen bonds interaction of ZnPZA with the catalytic amino acids Asp8 and Lys96 occurs for 83 and 40 ns, respectively. It is concluded that ZnPZA could serve as a transporter of PZA to the active site of PZAse, to promote the production of POA and the antituberculous effect; however, further experimental studies are needed.

scholarly journals Interaction of selected terpenoids with two SARS-CoV-2 key therapeutic targets: An in silico study through molecular docking and dynamics simulations

2021 ◽  
Vol 134 ◽  
pp. 104538
Author(s):  
Salvatore Vincenzo Giofrè ◽  
Edoardo Napoli ◽  
Nunzio Iraci ◽  
Antonio Speciale ◽  
Francesco Cimino ◽  
...  
Keyword(s):  
Molecular Docking ◽  
In Silico ◽  
Therapeutic Targets ◽  
In Silico Study ◽  
Dynamics Simulations ◽  
Molecular Docking And Dynamics

In Silico Study of Structural and Geometrical Requirements of Natural Sesquiterpene Lactones with Trypanocidal Activity

2013 ◽  
Vol 13 (10) ◽  
pp. 1407-1414 ◽  
Author(s):  
L. Fabian ◽  
V. Sulsen ◽  
F. Frank ◽  
S. Cazorla ◽  
E. Malchiodi ◽  
...  
Keyword(s):  
In Silico ◽  
Sesquiterpene Lactones ◽  
Trypanocidal Activity ◽  
In Silico Study

In Silico Study of 1, 4 Alpha Glucan Branching Enzyme and Substrate Docking Studies

2020 ◽  
Vol 17 (1) ◽  
pp. 40-50
Author(s):  
Farzane Kargar ◽  
Amir Savardashtaki ◽  
Mojtaba Mortazavi ◽  
Masoud Torkzadeh Mahani ◽  
Ali Mohammad Amani ◽  
...  
Keyword(s):  
Phylogenetic Tree ◽  
In Silico ◽  
Alpha Helix ◽  
In Silico Analysis ◽  
Glycogen Storage ◽  
Docking Studies ◽  
Random Coil ◽  
Special Topic ◽  
Industrial Biotechnology ◽  
In Silico Study

Background: The 1,4-alpha-glucan branching protein (GlgB) plays an important role in the glycogen biosynthesis and the deficiency in this enzyme has resulted in Glycogen storage disease and accumulation of an amylopectin-like polysaccharide. Consequently, this enzyme was considered a special topic in clinical and biotechnological research. One of the newly introduced GlgB belongs to the Neisseria sp. HMSC071A01 (Ref.Seq. WP_049335546). For in silico analysis, the 3D molecular modeling of this enzyme was conducted in the I-TASSER web server. Methods: For a better evaluation, the important characteristics of this enzyme such as functional properties, metabolic pathway and activity were investigated in the TargetP software. Additionally, the phylogenetic tree and secondary structure of this enzyme were studied by Mafft and Prabi software, respectively. Finally, the binding site properties (the maltoheptaose as substrate) were studied using the AutoDock Vina. Results: By drawing the phylogenetic tree, the closest species were the taxonomic group of Betaproteobacteria. The results showed that the structure of this enzyme had 34.45% of the alpha helix and 45.45% of the random coil. Our analysis predicted that this enzyme has a potential signal peptide in the protein sequence. Conclusion: By these analyses, a new understanding was developed related to the sequence and structure of this enzyme. Our findings can further be used in some fields of clinical and industrial biotechnology.

Exploring PLAC1 Structure and Underlying Mechanisms to Design a Derivative Vaccine Against Breast Cancer Progression; In-Silico Study

2020 ◽  
Vol 17 (5) ◽  
pp. 379-391
Author(s):  
Farzaneh Afzali ◽  
Parisa Ghahremanifard ◽  
Mohammad Mehdi Ranjbar ◽  
Mahdieh Salimi
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
In Silico ◽  
Tertiary Structure ◽  
Specific Antigen ◽  
Docking Simulation ◽  
Post Translational Modification ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Underlying Mechanisms

Background: The tolerogenic homeostasis in Breast Cancer (BC) can be surpassed by rationally designed immune-encouraging constructs against tumor-specific antigens through immunoinformatics approach. Objective: Availability of high throughput data providing the underlying concept of diseases and awarded computational simulations, lead to screening the potential medications and strategies in less time and cost. Despite the extensive effects of Placenta Specific 1 (PLAC1) in BC progression, immune tolerance, invasion, cell cycle regulation, and being a tumor-specific antigen the fundamental mechanisms and regulatory factors were not fully explored. It is also worth to design an immune response inducing construct to surpass the hurdles of traditional anti-cancer treatments. Methods and Result: The study was initiated by predicting and modelling the PLAC1 secondary and tertiary structures and then engineering the fusion pattern of PLAC1 derived immunodominant predicted CD8+ and B-cell epitopes to form a multi-epitope immunogenic construct. The construct was analyzed considering the physiochemical characterization, safety, antigenicity, post-translational modification, solubility, and intrinsically disordered regions. After modelling its tertiary structure, proteinprotein docking simulation was carried out to ensure the attachment of construct with Toll-Like Receptor 4 (TLR4) as an immune receptor. To guarantee the highest expression of the designed construct in E. coli k12 as an expressional host, the codon optimization and in-silico cloning were performed. The PLAC1 related miRNAs in BC were excavated and validated through TCGA BC miRNA-sequencing and databases; the common pathways then were introduced as other probable mechanisms of PLAC1 activity. Conclusion: Regarding the obtained in-silico results, the designed anti-PLAC1 multi-epitope construct can probably trigger humoral and cellular immune responses and inflammatory cascades, therefore may have the potential of halting BC progression and invasion engaging predicted pathways.

In Silico Study of Ethylene Biosynthesis: Seeking New Effectors of ACC Synthase and ACC Oxidase

2016 ◽  
Vol 11 (3) ◽  
pp. 346-356
Author(s):  
Nada Ayadi ◽  
Sarra Aloui ◽  
Rabeb Shaiek ◽  
Oussama Rokbani ◽  
Faten Raboud ◽  
...  
Keyword(s):  
In Silico ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
In Silico Study

In Silico Identification of a Potent Arsenic Based Approved Drug Darinaparsin against SARS-CoV-2: Inhibitor of RNA Dependent RNA polymerase (RdRp) and Essential Proteases

2020 ◽  
Vol 20 ◽  
Author(s):  
Trinath Chowdhury ◽  
Gourisankar Roymahapatra ◽  
Santi M. Mandal
Keyword(s):  
Rna Polymerase ◽  
Viral Entry ◽  
In Silico ◽  
Rna Dependent Rna Polymerase ◽  
Replication Complex ◽  
In Silico Study ◽  
Life Threatening ◽  
In Vivo Analysis ◽  
3Cl Protease

Background: COVID-19 is a life threatening novel corona viral infection to our civilization and spreading rapidly. Terrific efforts are generous by the researchers to search for a drug to control SARS-CoV-2. Methods: Here, a series of arsenical derivatives were optimized and analyzed with in silico study to search the inhibitor of RNA dependent RNA polymerase (RdRp), the major replication factor of SARS-CoV-2. All the optimized derivatives were blindly docked with RdRp of SARS-CoV-2 using iGEMDOCK v2.1. Results: Based on the lower idock score in the catalytic pocket of RdRp, darinaparsin (-82.52 kcal/mol) revealed most effective among them. Darinaparsin strongly binds with both Nsp9 replicase protein (-8.77 kcal/mol) and Nsp15 endoribonuclease (-8.3 kcal/mol) of SARS-CoV-2 as confirmed from the AutoDock analysis. During infection, the ssRNA of SARS-CoV2 is translated into large polyproteins forming viral replication complex by specific proteases like 3CL protease and papain protease. This is also another target to control the virus infection where darinaparsin also perform the inhibitory role to proteases of 3CL protease (-7.69 kcal/mol) and papain protease (-8.43 kcal/mol). Conclusion: In host cell, the furin protease serves as a gateway to the viral entry and darinaparsin docked with furin protease which revealed a strong binding affinity. Thus, screening of potential arsenic drugs would help in providing the fast invitro to in-vivo analysis towards development of therapeutics against SARS-CoV-2.

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