Journal of Biomolecular Structure & Dynamics最新文献

The Japanese encephalitis virus, (JEV), is a flavivirus mostly transmitted by Culex mosquitoes mostly present in Southeast Asia and the Western Pacific region. Ardeid-wading birds are the natural reservoir of JEV; nonetheless, pigs are frequently a key amplifying host during epidemics in human populations. Although more domestic animals and wildlife are JEV hosts, it is unclear how these animals fit into the ecology and epidemiology of the virus. Even though there is no specific therapy, vaccines are available to prevent this infection. However, current vaccinations do not work against every clinical isolate and can cause neurological problems in certain people. In this study, we have screened 501 phytochemical compounds from various plants from the Zingeberaceae family against the RdRp protein of JEV. Based on this, the top five compounds (IMPHY014466, IMPHY004928, IMPHY007097, IMPHY014179 and IMPHY005010) were selected based on the obtained docking scores, which was above -8.0 Kcal/mol. Further, the binding affinity of these selected ligands was also analysed using molecular interaction, and the presence of interactions like hydrogen bonds, hydrophobic bonds and polar bonds with respective active residues were identified and studied elaborately. Furthermore, the dynamic stability of the docked RdRp protein with these selected phytochemicals was studied using Molecular dynamic simulation and essential dynamics. The free energy landscape analysis also provided information about the energy transition responsible stability of the complex. The results obtained advocated phytochemical compounds from the zingeberaceae family for future experimental validation, as these compounds exhibited significant potential as JEV antagonists.

Spike glycoprotein has a significant role in the entry of SARS-CoV-2 to host cells, which makes it a potential drug target. Continued accumulation of non-synonymous mutations in the receptor binding domain of spike protein poses great challenges in identifying antiviral drugs targeting this protein. This study aims to identify potential entry inhibitors of SARS-CoV-2 using virtual screening and molecular dynamics (MD) simulations from three distinct chemical libraries including Pandemic Response Box, Drugbank and DrugCentral, comprising 6971 small molecules. The molecules were screened against a binding pocket identified in the receptor-binding domain (RBD) region of the spike protein which is known as the linoleic acid binding pocket, a highly conserved motif among several SARS-CoV-2 variants. Through virtual screening and binding free energy calculations, we identified four top-scoring compounds, MMV1579787 ([2-Oxo-2-[2-(3-phenoxyphenyl)ethylamino]ethyl]phosphonic acid), Tretinoin, MMV1633963 ((2E,4E)-5-[3-(3,5-dichlorophenoxy)phenyl]penta-2,4-dienoic acid) and Polydatin, which were previously reported to have antibacterial, antifungal or antiviral properties. These molecules showed stable binding on MD simulations over 100 ns and maintained stable interactions with TYR365, PHE338, PHE342, PHE377, TYR369, PHE374 and LEU368 of the spike protein RBD that are found to be conserved among SARS-CoV-2 variants. Our findings were further validated with free energy landscape, principal component analysis and dynamic cross-correlation analysis. Our in silico analysis of binding mode and MD simulation analyses suggest that the identified compounds may impede viral entrance by interacting with the linoleic acid binding site of the spike protein of SARS-CoV-2 regardless of its variants, and they thus demand for further in vitro and in vivo research.

The current research focuses on exploring tautomerism in uracil. 47 tautomers were found that varied in significance in RNA and stability. To discover these molecules, diverse potential energy levels were explored, and corresponding transition states were found in these pathways. But the imperative thing that was taken note in this investigation is that for the first time, a method was detailed for the probability of forming distinctive molecules relative to each other. In this method, the conversion of uracil and its tautomers, which together turn into 47 molecules, was composed as a Markov chain. Then, the transition matrix was explained using its support, whose components are the probability of creating molecules from each step. At last, by multiplying this matrix by n times, the probability of forming different molecules was obtained. Moreover, by solving this matrix at different times, it is conceivable to appear which molecules can be converted to uracil sooner. It was appeared that a few tautomers act as transitory absorption point or temporary terminal states and other molecules, to begin with convert to these molecules before turning into uracil.

Lung adenocarcinoma is highly heterogeneous at the molecular level between different stages; therefore, understanding molecular mechanisms contributing to such heterogeneity is needed. In addition, multiple stages of progression are critical factors for lung adenocarcinoma treatment. However, previous studies showed that cancer progression is associated with altered lncRNA expression, highlighting the tissue-specific and developmental stage-specific nature of lncRNAs in various diseases. Therefore, a study using an integrated network approach to explore the role of lncRNA in carcinogenesis was done using expression profiles revealing stage-specific and conserved lncRNA biomarkers in lung adenocarcinoma. We constructed ceRNA networks for each stage of lung adenocarcinoma and analysed them using network topology, differential co-expression network, protein-protein interaction network, functional enrichment, survival analysis, genomic analysis and deep learning to identify potential lncRNA biomarkers. The co-expression networks of healthy and three successive stages of lung adenocarcinoma have shown different network properties. One conserved and four stage-specific lncRNAs are identified as genome regulatory biomarkers. These lncRNAs can successfully identify lung adenocarcinoma and different stages of progression using deep learning. In addition, we identified five mRNAs, four miRNAs and twelve novel carcinogenic interactions associated with the progression of lung adenocarcinoma. These lncRNA biomarkers will provide a novel perspective into the underlying mechanism of adenocarcinoma progression and may be further helpful in early diagnosis, treatment and prognosis of this deadly disease.

Kirsten rat sarcoma (KRAS) stands out as the most prevalent mutated oncogene, playing a crucial role in the initiation and progression of various cancer types, including colorectal, lung and pancreatic cancer. The oncogenic modifications of KRAS are intricately linked to tumor development and are identified in 22% of cancer patients. This has spurred the necessity to explore inhibition mechanisms, with the aim of investigating and repurposing existing drugs for diagnosing cancers dependent on KRAS G12C In this investigation, 26 nucleoside-based drugs were collected from literature to assess their effectiveness against KRAS G12C. The study incorporates in-silico molecular simulations and molecular docking examinations of these nucleoside-derived drugs with the KRAS G12C protein using Protein Data Bank (PDB) ID: 5V71. The docking outcomes indicated that two drugs, Azacitidine and Ribavirin, exhibited substantial binding affinities of -8.7 and -8.3 kcal/mol, respectively. These drugs demonstrated stability in binding to the active site of the protein during simulation studies. Root mean square deviation (RMSD) analyses indicated that the complexes closely adhered to an equilibrium RMSD value ranging from 0.17 to 0.2 nm. Additionally, % occupancies, bond angles and the length of hydrogen bonds were calculated. These findings suggest that Azacitidine and Ribavirin may potentially serve as candidates for repurposing in individuals with KRAS-dependent cancers.

A polymeric compound formulized as [Cu(µ-dipic)₂{Na₂(µ-H₂O)₄]_n.2nH₂O (I), where dipic is 2,6-pyridine dicarboxylic acid (dipicolinic acid, H₂dipic), was synthesized by sonochemical irradiation. The initial in-vitro cytotoxic activity of this complex compared with renowned anticancer drugs like cisplatin, versus HCT116 colon cell lines, shows promising results. This study investigated the interaction mode between compound (I) and calf-thymus DNA utilizing a range of analytical techniques including spectrophotometry, fluorimetry, partition coefficient analysis, viscometry, gel electrophoresis and molecular docking technique. The results obtained from experimental methods reveal complex (I) could bind to CT-DNA via hydrogen bonding and van der Waals forces and the theoretical methods support it. Also, complex (I) indicates nuclease activity in the attendance of H₂O₂ and can act as an artificial nuclease to cleave DNA with high efficiency.

Cervical cancer poses a significant global health challenge, ranking as the fourth most common cancer among women worldwide and resulting in approximately 300,000 deaths yearly, predominantly caused by high-risk human papillomavirus strains (HPV), mainly types 16 and 18. The scenario poses the urgent need of the hour to develop effective treatment strategies that can address the complexity of cervical cancer and multitargeted inhibitor designing that holds promise as it can simultaneously target multiple proteins and pathways involved in its progression and have the potential to enhance treatment efficacy, reduce the likelihood of drug resistance. In this study, we have performed multitargeted molecular docking of FDA-approved drugs against cervical cancer replication and maintenance proteins- Xenopus kinesin-like protein-2 (3KND), cell division cycle protein-20 (4N14), MCM2-histone complex (4UUZ) and MCM6 Minichromosome maintenance (2KLQ) with HTVS, SP and XP algorithms and have obtained the docking and MMGBSA score ranging from -8.492 to -5.189 Kcal/mol and -58.16 to -39.07 Kcal/mol. Further, the molecular interaction fingerprints identified ALA, THR, SER, ASN, LEU, and ILE were among the most interacted residues, leaning towards hydrophobic and polar amino acids. The pharmacokinetics and DFT of the compound have shown promising results. The complexes were simulated for 100 ns to study the stability by computing the deviation, fluctuations, and intermolecular interactions formed during the simulation. This study produced promising results, satisfying the criteria that Mitoxantrone 2HCl can be a multitargeted inhibitor against cervical cancer proteins-however, experimental validation is a must before human use.

Complement C5 is the target of the monoclonal antibody eculizumab, used in complement dysregulating disorders, like the rare disease Paroxysmal Nocturnal Hemoglobinuria (PNH). PNH is an acquired hematopoietic stem cell condition characterized by aberrant destruction of erythrocytes, chronic hemolytic anemia, and thromboembolism propensity. C5 is a protein component of the complement system which is part of the immune system of the body and plays a prominent role in the destruction of red blood cells, misidentifying them as a threat. This work describes the application of molecular dynamics simulations to the study of the underlying interactions between complement C5 and eculizumab. This study also reveals the importance of single nucleotide polymorphisms on C5 protein concerning the effective inhibition of the mAB, involving the mechanistic events taking place at the interface spots of the complex. The predicted conformational change in the C5 Arg⁸⁸⁵/His/Cys mutation has implications on the protein's interaction with eculizumab, compromising their compatibility. The acquired insights into the conformational changes, dynamics, flexibility, and interactions shed light on the knowledge of the function of this biomolecule providing answers about the poor response to the treatment in PNH patient carriers of the mutations. By investigating the intricate dynamics, significant connections between C5 and eculizumab can be uncovered. Such insights may aid in the creation of novel compounds or lead to the enhancement of eculizumab's efficacy.

Various serum proteins, like Human Serum Albumin (HSA) and others, are susceptible to glycation and the formation of Advanced Glycation End Products (AGEs). Diabetes and other diseases are associated with AGE development. Recently, isoflavones have been studied for their therapeutic benefits. In the present study, we glycated HSA with Methylglyoxal (MGO) with and without the test compound, i.e., Biochanin A (BCA), to test its antiglycating capacity. We studied the biochemical and biophysical effects of glycation on HSA with and without BCA and also took the help of the in silico technique. Analytical methods included intrinsic and extrinsic fluorescence, polyacrylamide gel electrophoresis (PAGE), UV spectroscopy, far UV circular dichroism, and others. For structural comprehension, TEM and SEM were used. Molecular docking and simulation were employed to observe BCA-HSA's site-specific interaction. Since HSA is a therapeutically relevant protein involved in many disorders, this study's findings are important.

Gamma secretase (GS) is an important therapeutic target in anticancer drug discovery. Increased GS activity activates notch signaling pathway which is associated with cancer stemness and drug resistance in cancer cells. A total of 69,075 natural and their derivative compounds were screened to identify the lead compound on the basis of in silico GS catalytic domain binding potential and in vitro selective anticancer efficacy. STOCK1N-23234 showed higher dock score (-11.82) compared to DAPT (-9.2) in molecular docking experiment and formed hydrogen bond with the key amino acid (Asp385) involve in catalysis process. Molecular dynamics (MD) simulation parameters (RMSD, RMSF, Rg, SASA and hydrogen bond formation) revealed that the STOTCK1N-23234 formed structurally and energetically stable complex with the GS catalytic domain with lower binding energy (-22.79 kcal/mol) compared to DAPT (-16.22 kcal/mol). STOCK1N-23234 showed better toxicity (up to 60%) against colon and breast cancer cells (HCT-116 and MDA-MB-453) at 1-70 µM concentration. Interestingly, STOCK1N-23234 did not showed cytotoxicity against human normal breast cells (MCF-10A). STOCK1N-23234 treatment significantly decreased sphere formation, notch promoter activity, and transcription of notch target genes (Hes-1 and Hey-1) in HCT-116 cells derived colonosphere. Confocal microscopy revealed that STOTCK1N-23234 treatment at test concentration induced apoptosis related morphological changes, reduced mitochondria membrane potential and increased reactive oxygen species production in HCT-116 cells compared to non-treated cells. In conclusion, STOCK1N-23234 is a novel lead natural anticancer compound which requires in depth validation in cancer preclinical models.