A Study Modeling Bridged Nucleic Acid-Based ASOs and Their Impact on the Structure and Stability of ASO/RNA Duplexes.

Antisense medications treat diseases that cannot be treated using traditional pharmacological technologies. Nucleotide monomers of bare and phosphorothioate (PS)-modified LNA, N-MeO-amino-BNA, 2',4'-BNA[NH], 2',4'-BNA[NMe], and N-Me-aminooxy-BNA antisense modifications were considered for a detailed DFT-based quantum chemical study to estimate their molecular-level structural and electronic properties. Oligomer hybrid duplex stability is described by performing an elaborate MD simulation study by incorporating the PS-LNA and PS-BNA antisense modifications onto 14-mer ASO/RNA hybrid gapmer type duplexes targeting protein PTEN mRNA nucleic acid sequence (5'--3'/3'-GAAUCGUGACCGGA-5').

Evaluating therapeutic potential of AYUSH-64 constituents against omicron variant of SARS-CoV-2 using ensemble docking and simulations.

The COVID-19 pandemic in the later phase showed the presence of the B.1.1.

In-silico evaluation of Oroxylum indicum vent compounds in the plausible treatment and prevention of nasopharyngeal cancer.

Background: Shyonaka (Oroxylum indicum Vent) is widely used in Ayurveda and in ethnomedical practice for the treatment of inflammation, pain, diarrhea, non-healing ulcers, and cancer. Owing to the high prevalence of Epstein-Barr virus (EBV) infection in Nasopharyngeal carcinoma (NPC) patients, simultaneous targeting of proteins involved in both EBV replication and NPC proliferation might help to manage the disease effectively.

Objectives: This study is designed to identify potential dual targeting inhibitors from Oroxylum indicum having the potential to inhibit both EBV and NPC.

Probing the structure of human tRNA in the presence of ligands using docking, MD simulations and MSM analysis.

The tRNA, which acts as a primer for human immunodeficiency virus type 1 (HIV-1) reverse transcription, undergoes structural changes required for the formation of a primer-template complex. Small molecules have been targeted against tRNA to inhibit the primer-template complex formation. The present study aims to understand the kinetics of the conformational landscape spanned by tRNA in apo form using molecular dynamics simulations and Markov state modeling.

Design of LNA Analogues Using a Combined Density Functional Theory and Molecular Dynamics Approach for RNA Therapeutics.

Antisense therapeutics treat a wide spectrum of diseases, many of which cannot be addressed with the current drug technologies. In the quest to design better antisense oligonucleotide drugs, we propose five novel LNA analogues (A1-A5) for modifying antisense oligonucleotides and establishing each with the five standard nucleic acids: adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U). Monomer nucleotides of these modifications were considered for a detailed Density Functional Theory (DFT)-based quantum chemical analysis to determine their molecular-level structural and electronic properties.

Structural insight into locked nucleic acid based novel antisense modifications: A DFT calculations at monomer and MD simulations at oligomer level.

In the present study, five novel LNA based antisense modifications have been proposed. A conformational search was carried out using TANGO, followed by geometry optimization using MOPAC. Based on their electronic energies the most stable conformation for each modification was identified.

Remdesivir-bound and ligand-free simulations reveal the probable mechanism of inhibiting the RNA dependent RNA polymerase of severe acute respiratory syndrome coronavirus 2.

The efforts towards developing a potential drug against the current global pandemic, COVID-19, have increased in the past few months. Drug development strategies to target the RNA dependent RNA polymerase (RdRP) of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) are being tried worldwide. The gene encoding this protein, is known to be conserved amongst positive strand RNA viruses.

TANGO: A high through-put conformation generation and semiempirical method-based optimization tool for ligand molecules.

Lead optimization is one of the crucial steps in the drug discovery pipeline. After identifying the lead molecule and obtaining its 2D geometry, understanding the best conformation it would attain in 3D still remains one of the most challenging steps in drug discovery. There have been multiple methods and algorithms that are directed toward achieving best conformation for the lead molecules.

Structural insight into antisense gapmer-RNA oligomer duplexes through molecular dynamics simulations.

There is an extensive research carrying out on antisense technology and the molecules entering into clinical trials are increasing rapidly. Phosphorothioate (PS) is a chemical modification in which nonbridged oxygen is replaced with a sulfur, consequently providing resistance against nuclease activity. The 2'-4' conformationally restricted nucleoside has the structural features of both 2'-O-methoxy ethyl RNA (MOE), which shows good toxicity profile, and locked nucleic acid (LNA), which shows good binding affinity towards the target RNA.

Auto-regulation of Slug mediates its activity during epithelial to mesenchymal transition.

Slug, a five C2H2 zinc finger (ZF) motif transcription factor mediates cell migration in development, adult tissue repair and regeneration, as well as during tumor metastases through epithelial to mesenchymal transition. At the molecular level, this involves interactions with E-box (CACC/GGTG) consensus elements within target gene promoters to achieve transcriptional repression. However, precise elucidation of events involved in this DNA recognition and binding of specific promoters to regulate target genes have not been achieved.

Structural insights into the interactions of xpt riboswitch with novel guanine analogues: a molecular dynamics simulation study.

Ligand recognition in purine riboswitches is a complex process requiring different levels of conformational changes. Recent efforts in the area of purine riboswitch research have focused on ligand analogue binding studies. In the case of the guanine xanthine phosphoribosyl transferase (xpt) riboswitch, synthetic analogues that resemble guanine have the potential to tightly bind and subsequently influence the genetic expression of xpt mRNA in prokaryotes.

MD simulations of HIV-1 RT primer-template complex: effect of modified nucleosides and antisense PNA oligomer.

Human immunodeficiency virus type 1 (HIV-1) requires the human tRNA(3)(Lys) as a reverse transcriptase (RT) primer. The annealing of 3' terminal 18 nucleotides of tRNA(3)(Lys) with the primer binding site (PBS) of viral RNA (vRNA) is crucial for reverse transcription. Additional contacts between the A rich (A-loop) region of vRNA and the anticodon domain of tRNA(3)(Lys) are necessary, which show the specific requirement of tRNA(3)(Lys).