Molecular modeling, molecular dynamics simulation, and essential dynamics analysis of grancalcin: An upregulated biomarker in experimental autoimmune encephalomyelitis mice

Fe3O4@SiO2-SnCl4-promoted synthesis, cytotoxic evaluation, molecular docking, and MD simulation of some indenopyrido[2,3-d]pyrimidine derivatives

In this study, an efficient and environmentally friendly method for the one-pot synthesis of indenopyrido[2,3-d]pyrimidine derivatives was developed using Fe3O4@SiO2-SnCl4 nanoparticles as a catalyst. Indenopyrido[2,3-d]pyrimidines (4a-4j) were synthesized via three-component couplings of 6-amino-2-(methylthio)pyrimidin-4(3H)-one, 1,3-indanedione, and aldehydes in water as the solvent. In this reaction, Fe3O4@SiO2-SnCl4 demonstrated a highly catalytic nature, an easy handling procedure, short reaction times, recyclability exploitation, and excellent yields. The cytotoxic activities of the synthesized indenopyrido[2,3-d] pyrimidines analogues were evaluated against three cancer cell lines; MCF-7 (breast carcinoma), A549 (lung non-small cell carcinoma), and SKOV3 (ovarian carcinoma) using MTT assay. Additionally, molecular docking studies and molecular dynamics (MD) simulation of the investigated compounds was performed to verify their binding modes toward EGFR kinase receptor as the possible targets. This analysis aimed to predict the antitumor mechanisms of the synthesized compounds. The binding free energy values of the compounds showed a satisfactory correlation with their cytotoxic activities.

Multi-computational screening identifies homovanillic acid as a potential SAP5 inhibitor against Candida albicans biofilms

This work aims to find inhibitors of SAP5, a virulence factor in Candida albicans polymicrobial biofilms. The methodology included docking simulations, MMGBSA calculations, and molecular dynamics simulations. Of the 107 phenolic acids retrieved from PubChem, 20 passed ADMET screening. The research finds homovanillic acid to be a possible SAP5 inhibitor, with a binding energy of -19.92 kcal/mol as shown by molecular docking and MMGBSA analysis. The compound showed favorable ADMET properties, indicating low toxicity and high drug-likeness. Molecular dynamics simulations over 100 nanoseconds confirmed stable protein-ligand interactions. These findings suggest homovanillic acid's potential in treating AMR-associated biofilms and establish a foundation for experimental validation. The study demonstrates how computational methods can accelerate the discovery of novel antifungal medicines targeting polymicrobial infections.

Synthesizing network pharmacology, bioinformatics, and in vitro experimental verification to screen candidate targets of Salidroside for mitigating Alzheimer's disease

Alzheimer's disease (AD) is a neurological disorder leading to cognitive deficits. Salidroside (Sal), a primary bioactive ingredient extracted from the roots of Rhodiola rosea L., has potent neuroprotective effects in AD. However, studies on potential targets for Sal-anchored AD are limited. In this study, we combined network pharmacology, bioinformatics, and experimental validation to identify potential targets of Sal treating AD. First, we screened 10 pyroptosis-related genes (PRGs) in Sal and AD using public databases. Then, we used Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes enrichment analysis to explore the biological functions of the shared PRGs (Sal and AD). This finding exhibited that pathways linked to inflammation, like the nucleotide oligomerization domain (NOD)-like receptors signaling pathway, are important for Sal to help fight AD. The GeneMANIA functional results subsequently revealed an association between AD and the processes of inflammasome complex and inflammatory response. Additionally, nine hub genes were identified in the protein-protein interaction network of these shared PRGs. Subsequent analysis of the genes and phenotypes confirmed that these nine hub genes were directly correlated with AD. Subsequently, an in vitro AD model was created using rat adrenal pheochromocytoma cell line (PC12) cells induced by amyloid β-peptide (Aβ) 25-35 (20 µM). Sal significantly reduced the pyroptosis caused by Aβ 25-35 in PC12 cells and decreased the expression levels of IL-1β, CASP1, IL-18, PYCARD, and NLRP3. Furthermore, molecular docking and molecular dynamics simulations confirmed that Sal could stably bind to NLRP3. Druggability analysis revealed that Sal had excellent druggability. These results demonstrated that Sal could alleviate AD by targeting IL-1β, CASP1, IL-18, PYCARD, and NLRP3 to regulate the NLRP3-mediated pyroptosis signaling pathway.

Comprehensive metabolite profiling and evaluation of anti-nociceptive and anti-inflammatory potencies of Nypa fruticans (Wurmb.) leaves: Experimental and in-silico approaches

Globally, inflammation and pain are among the most prevalent health issues. The use of medicinal plants to alleviate these conditions is growing. This study comprehensively investigated the analgesic and anti-inflammatory properties of the ethyl-acetate extract of Nypa fruticans (EENF) leaves, traditionally used in folk Medicine. High-performance liquid chromatography (HPLC) and gas chromatography-mass spectroscopy (GC-MS) were employed to identify the phytochemicals in EENF. In vitro antioxidant studies were conducted to determine the antioxidative properties of EENF. Formalin-induced paw edema assay was employed to assess the in-vivo anti-inflammatory activity whereas; acetic acid-induced writhing test, hot plate test, and tail immersion test were performed to evaluate the in vivo anti-nociceptive effects. The identified compounds were subsequently evaluated by computational studies against the cyclooxygenase-2 enzyme. EENF demonstrated significant antioxidant activity in both the DPPH scavenging assay (IC50: 105.18 μg/mL) and the reducing power assay (RC50:1752.76 μg/mL). In the in-vivo anti-inflammatory assay, EENF exhibited the highest (50.39 % and 67.72 %) inhibition of edema at the fourth hour at 200 and 400 mg/kg body weight, accordingly. Moreover, all the pain modulation studies demonstrated significant (p < 0.001) analgesic properties of EENF in a dose-dependent manner. Among, the 23 identified phytocompounds, the most promising ones were determined to be potential anti-nociceptive and anti-inflammatory agents through molecular docking studies and ADME/T analysis. Molecular dynamics simulations (MDS) confirmed the stability of the protein-ligand complexes. Two phytochemicals, (-) Epicatechin (CID 72276) and Quercetin (CID 5280343), outperformed the standard anti-inflammatory drug, diclofenac sodium, in MDS studies. Both experimental and in-silico studies have scientifically verified the traditional use of Nypa fruticans in treating pain and inflammatory disease. Overall, (-) Epicatechin and Quercetin possess excellent potential as natural lead compounds for COX-2 inhibition. Further research, including pure compound isolation and biomolecular studies, is needed to understand the underlying mechanisms of these activities.

Molecular dynamics simulation of wild and mutant proteasome subunit beta type 8 (PSMB8) protein: Implications for restoration of inflammation in experimental autoimmune encephalomyelitis pathogenesis

Multiple Sclerosis (MS) is an autoimmune and chronic disease in the brain and spinal cord. MS has inflammatory progression characterized by its hallmark inflammatory plaques. The histological and clinical characteristics of MS are shared by Experimental Autoimmune Encephalomyelitis (EAE). Genetic and environmental factors contribute to the development of MS. In EAE-MS disease, the level of proteasome subunit beta type-8 (PSMB8), encoded by the PSMB8 gene, is increased and regulates the inflammatory response in this disease. In humans, the Nakajo-Nishimura Syndrome is caused by a mutation in the gene PSMB8, a part of the immunoproteasome subunit. Therefore, special attention to wild and mutant (G210V) PSMB8 protein is imperative. In this study, we performed a 100 ns molecular dynamics (MD) simulation for wild-type PSMB8 and the mutant G210V. Then, we analyzed the fundamental and essential simulation results using another Google Colab system. The energy analysis ensures the structural deviation due to point mutation. The trajectory of the fundamental simulation (RMSD, RMSF, and Rg) describes that the G210V mutated protein is more flexible and less stable than the wild type. We observed the conformational changes due to mutation by analyzing the RMSD average linkage hierarchical clustering, total SASA, and SASA autocorrelation. The differences in the protein's overall motion and the atoms' precise location are identified by the principal component analysis, showing that the overall motion and location of the atoms are different. Our study provides valuable insights into the dynamics and structure of this protein, which can aid in further understanding its biological functions and potential implications for disease.

Design of a Multiepitope Pan-Proteomic mRNA Vaccine Construct Against African Swine Fever Virus: A Reverse Vaccinology Approach

African swine fever (ASF), caused by African swine fever virus (ASFV), is a highly contagious disease with devastating effects on the global pig industry. This warrants the development of effective control strategies, such as vaccines. However, previously developed inactivated vaccines have proven ineffective, while live-attenuated vaccines carry inherent safety risks. The use of mRNA vaccines eliminates these risks offering a safe, cost-effective, and efficient vaccine strategy against ASFV. In this study, a reverse vaccinology approach was used to design a multiepitope pan-proteomic mRNA vaccine against ASFV. Various bioinformatics tools were employed to predict epitopes for cytotoxic T lymphocytes, helper T lymphocytes, and B lymphocytes. A 50S ribosomal L7/L12 protein adjuvant, 5' cap, poly(A) tail, signal peptide, and MHC-I-targeting domain were incorporated into the design using appropriate linkers to increase immunogenicity, stability, and recognition efficiency. The physicochemical properties of the final construct were evaluated, and docking analyses were done with Toll-like receptors (TLRs) 3, 4, and 7 to evaluate binding affinity. A molecular dynamics simulation was then performed to determine binding stability, while immune simulations evaluated host's immune response. Based on 100 ASFV proteomes, six epitopes that induce cytotoxic T-cell responses, five epitopes that induce helper T-cell responses, and four epitopes that induce antibody production were predicted. The designed vaccine construct was found to be nonallergenic, antigenic, and stable when bound to TLR4 while the binding pocket analyses of the vaccine construct to TLR3 and TLR7 indicate high translation efficiency. Immune simulations demonstrated successful induction of immune responses and generation of antigen-specific memory cells. In conclusion, this study introduces an mRNA vaccine construct as a potential disease control strategy against ASF for in vitro confirmation.

A review on description dynamics and conformational changes of proteins using combination of principal component analysis and molecular dynamics simulation

Understanding how proteins behave dynamically and undergo conformational changes is essential to comprehending their biological roles. This review article examines the potent tool of using Molecular Dynamics simulations in conjunction with Principal Component Analysis (PCA) to explore protein dynamics. Molecular dynamics data can be made easier to read by removing prominent patterns through the use of PCA, a sophisticated dimensionality reduction approach. Researchers can obtain critical insights into the fundamental principles governing protein function by using PCA on MD simulation data. We provide a systematic approach to PCA that includes data collection, input coordinate selection, and result interpretation. Protein collective movements and fundamental dynamics are made visible by PCA, which makes it possible to identify conformational substates that are crucial to function. By means of principal component analysis, scientists are able to observe and measure large-scale movements, like hinge bending and domain motions, as well as pinpoint areas of protein structural stiffness and flexibility. Moreover, PCA allows temporal separation, distinguishing slower global motions from faster local changes. A strong foundation for researching protein dynamics is provided by the combination of PCA and Molecular Dynamics simulations, which have applications in drug development and enhance our comprehension of intricate biological systems.

Screening of phytoconstituents from Bacopa monnieri (L.) Pennell and Mucuna pruriens (L.) DC. to identify potential inhibitors against Cerebroside sulfotransferase

Cerebroside sulfotransferase (CST) is considered a target protein in developing substrate reduction therapy for metachromatic leukodystrophy. This study employed a multistep virtual screening approach for getting a specific and potent inhibitor against CST from 35 phytoconstituents of Bacopa monnieri (L.) Pennell and 31 phytoconstituents of Mucuna pruriens (L.) DC. from the IMPPAT 2.0 database. Using a binding score cutoff of -8.0 kcal/mol with ADME and toxicity screening, four phytoconstituents IMPHY009537 (Stigmastenol), IMPHY004141 (alpha-Amyrenyl acetate), IMPHY014836 (beta-Sitosterol), and IMPHY001534 (jujubogenin) were considered for in-depth analysis. In the binding pocket of CST, the major amino acid residues that decide the orientation and interaction of compounds are Lys85, His84, His141, Phe170, Tyr176, and Phe177. The molecular dynamics simulation with a 100ns time span further validated the stability and rigidity of the docked complexes of the four hits by exploring the structural deviation and compactness, hydrogen bond interaction, solvent accessible surface area, principal component analysis, and free energy landscape analysis. Stigmastenol from Bacopa monnieri with no potential cross targets was found to be the most potent and selective CST inhibitor followed by alpha-Amyrenyl acetate from Mucuna pruriens as the second-best performing inhibitor against CST. Our computational drug screening approach may contribute to the development of oral drugs against metachromatic leukodystrophy.

Exploration of phytoconstituents of Medhya Rasayana herbs to identify potential inhibitors for cerebroside sulfotransferase through high-throughput screening

Cerebroside sulfotransferase (CST) is a key enzyme in sulfatide biosynthesis and regulation of the myelin sheath in the nervous system. To counter sulfatide accumulation with the deficiency of aryl sulfatase A, CST is considered a target protein in substrate reduction therapy in metachromatic leukodystrophy. In this study, 461 phytoconstituents from four herbs of Medhya Rasayana were screened using multi-pronged virtual screening methods including molecular docking, molecular dynamics (MD) simulation, and reverse pharmacophore analysis. The initial screening of the top 15 hits was based on the binding affinity of the compounds toward the CST substrate-binding site using the lowest free energy of a binding score cutoff of ≤ -7.5 kcal/mol, with the number of conformations in the largest cluster more than 75. The absorption, distribution, metabolism, and excretion (ADME) and toxicity-based pharmacokinetic analysis delivered the top four hits: 18alpha-glycyrrhetinic acid, lupeol, alpha carotene, and beta-carotene, with high blood-brain barrier permeability and negligible toxicity. Furthermore, a 100-ns simulation of protein-ligand complexes with a trajectory analysis of structural deviation, compactness, intramolecular interactions, principal component analysis, free energy landscape, and dynamic cross-correlation analysis showed the binding potential and positioning of the four hits in the binding pocket. Thus, an in-depth analysis of protein-ligand interactions from pre- and post-molecular dynamics simulation, along with reverse pharmacophore mapping, suggests that 18alpha-glycyrrhetinic acid is the most potent and specific CST inhibitor, while beta-carotene could be considered the second most potent compound for CST inhibition as it also exhibited overall stability throughout the simulation. Therefore, the computational drug screening approach applied in this study may contribute to the development of oral drugs as a therapeutic option for metachromatic leukodystrophy.

Molecular dynamics and experimental analysis of energy behavior during stress relaxation in magnetorheological elastomers

The diverse applications of magnetorheological elastomer (MRE) drive efforts to understand consistent performance and resistance to failure. Stress relaxation can lead to molecular chain deterioration, degradation in stiffness and rheological properties, and ultimately affect the life cycle of MRE. However, quantifying the energy and molecular dynamics during stress relaxation is challenging due to the difficulty of obtaining atomic-level insights experimentally. This study employs molecular dynamics (MD) simulation to elucidate the stress relaxation in MRE during constant strain. Magnetorheological elastomer models incorporating silicone rubber filled with varying magnetic iron particles (50-80 wt%) were constructed. Experimental results from an oscillatory shear rheometer showed the linear viscoelastic region of MRE to be within 0.001-0.01% strain. The simulation results indicated that stress relaxation has occurred, with stored energies decreased by 8.63-52.7% in all MRE models. Monitoring changes in energy components, the highest final stored energy (12,045 kJ) of the MRE model with 80 wt% Fe particles was primarily attributed to stronger intramolecular and intermolecular interactions, revealed by higher potential energy (3262 kJ) and van der Waals energy (- 2717.29 kJ). Stress relaxation also altered the molecular dynamics of this MRE model as evidenced by a decrease in kinetic energy (9362 kJ) and mean square displacement value (20,318 Å2). The MD simulation provides a promising quantitative tool for elucidating stress relaxation, preventing material failure and offering insights for the design of MRE in the nanotechnology industry.

Molecular structure, vibrational spectral, electron density analysis on linaloe oil and molecular docking efficacy against the therapeutic target on human immunodeficiency virus-1 organism (VIRAL protein)

Natural traditional medicine extensively uses certain terpenes and gives plants their flavor, aroma, and color. Treatments for bacterial infections, malaria, and cardiovascular disorders, anti-inflammatory, promote circulation, and heal wounds. 3,7-Dimethyl-1,6-octadien-3-ol (Linalool) is a naturally occurring monoterpene alcohol with no cycle and is a colorless liquid. Spectral analysis such as UV absorption spectra, NMR for structure determination, and IR and Raman for vibrational analysis. The Quantum mechanical approach uses DFT, ELF, and LOL-promolecular electron density, non-relaxed, and atomic density analysis. The biomolecular studies such as molecular dynamics using protein-ligand complex with HIV-1 organism (energy minimization). ADMET for the usage of linalool in different metabolism studies and Molecular docking for binding affinity, its reactive site estimation, and macromolecules that come into contact with protein receptors and conclude ligand binding affinity with protein.

Identification of novel umami peptides from yeast extract and the mechanism against T1R1/T1R3

Yeast extract was separated by using ultrafiltration, gel filtration chromatography, and preparative high-performance liquid chromatography for analyzing the umami mechanism. 13 kinds of umami peptides were screened out from 73 kinds of peptides which were identified in yeast extract using nanoscale ultra-performance liquid chromatography-tandem mass spectrometry and virtual screening. The umami peptides were found to have a threshold range of 0.07-0.61 mM. DWTDDVEAR exhibited a strong umami taste with a pronounced enhancement effect for monosodium glutamate. Molecular docking studies revealed that specific amino acid residues in the T1R1 subunit, including Arg316, Ser401, and Asp315, played a critical role in the umami perception with these peptides. Overall, the study highlights the potential of natural flavor enhancers and provides insights into the mechanism of umami taste perception.