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Results for “Molecular Docking Simulation”

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PubMed2026

Discovery and characterization of multifunctional bioactive peptides from Alaska Pollock (Gadus chalcogrammus) milt: hybrid in silico, in vitro, and proteomic approaches.

The growing demand for multifunctional bioactive peptides has sparked interest in underutilized marine by-products as sustainable bioresources. This study explored Alaska Pollock (Gadus chalcogrammus) milt protein as a novel source of peptides with anti-inflammatory, anti-hypertensive, and anti-diabetic effects. Protein composition was analyzed via LC-MS, followed by in silico digestion and bioactivity prediction. Molecular docking identified peptides targeting DPP-IV, α-glucosidase, ACE, GLP-1 receptor, COX-2, MuRF1, and the 20S proteasome. Among the candidates, a promising peptide (CLPPH) was synthesized and validated in vitro, demonstrating inhibitory effects on nitric oxide production, DPP-IV, ACE, and α-glucosidase. These results highlight CLPPH's potential as a multifunctional bioactive peptide and support the valorization of Alaska Pollock milt as a sustainable source for functional foods and nutraceutical applications.

Animals↗

PubMed2026

Inhibitory mechanism of anthocyanin B-ring substituents on advanced glycation end-product formation through bovine serum albumin binding: Insights from multispectral, molecular docking and proteomics approaches.

This study demonstrated that the inhibitory effect of anthocyanins on AGEs formation is highly dependent on the substitution pattern of the B-ring. Among the four anthocyanins, delphinidin-3-O-glucoside (D3G) exhibited the most potent antiglycation activity across BSA-fructose, MGO, and GO models with half-maximal inhibitory concentration (IC50) of 30.77, 200.29 and 269.97 μM. This superior performance was attributed to the presence of three hydroxyl groups on the B-ring, which facilitates a high-affinity, spontaneous binding interaction with BSA primarily through hydrophobic forces and hydrogen bonding. Spectroscopic and computational analyses revealed that D3G effectively stabilizes the protein scaffold, specifically recovering α-helix content and shielding critical subdomains (IB, IIA, and IIIA). Proteomics data are consistent with a protective binding mechanism, suggesting that D3G reduces the accessibility of key lysine and arginine residues to glycation-induced modifications. These findings provide a structural basis for developing D3G-rich extracts as targeted, structure-based functional ingredients to mitigate glycation-associated food quality degradation and related health issues.

Anthocyanins↗

PubMed2025

Molecular mechanism of HaiZao-YuHu decoction in breast cancer treatment via network pharmacology and molecular docking: Computational pharmacology.

BACKGROUND: The molecular biological mechanisms of HaiZao-YuHu decoction were investigated using network pharmacology and molecular docking. METHODS: TCMSP database was used to collect the active ingredients and action targets of HaiZao-YuHu decoction, through the OMIM, PharmGkb, GeneCards, TDD, and DurgBank database query targets for breast cancer. Then, using the intersecting targets, the protein-protein interaction network of HaiZao-YuHu decoction was constructed using the STRING website. Network topology analysis was performed using Cytoscape 3.9.0 to identify the core targets. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed with the R package. The Autodock software was used for molecular docking. RESULTS: Thirty-four active ingredients, 219 intersection targets and 4 key targets were obtained. gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis get 2152 biological processes and 186 pathways. Molecular docking showed that the 4 core targets could combine well with the 5 main active components. CONCLUSION: HaiZao-YuHu decoction can play a role in the treatment of breast cancer through multi-targets, multi-components, and multi-pathways.

Molecular Docking Simulation↗

PubMed2025

Investigating the molecular mechanism of Yangxin decoction in treating major depressive disorder using network pharmacology and molecular docking technology approaches.

Yangxin decoction has been used to treat major depressive disorder (MDD). This study aims to identify the active components and potential mechanisms of Yangxin decoction in treating MDD using network pharmacology and molecular docking technology. The active components and targets of Yangxin decoction were screened, and MDD-related targets were predicted. Networks of "herbal medicine-active components-potential targets" and protein-protein interaction were constructed. Core components and core targets were identified through network topology analysis. Gene ontology functional and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed on candidate genes. Molecular docking was conducted using AutoDock software (Olson Laboratory of the Scripps Research Institute, San Diego) to explore the interactions between core targets and active components, and the results were visualized using PyMOL (DeLano Scientific LLC, South San Francisco). A total of 433 active components and 392 targets of Yangxin decoction were identified, along with 11,796 MDD-related targets. There were 680 overlapping targets between Yangxin decoction and MDD, associated with 104 active components. Core targets identified through network topology analysis and molecular docking included serine/threonine kinase 1 (AKT1), tumor necrosis factor, interleukin-6, tumor protein P53, and proto-oncogene tyrosine-protein kinase Src. Gene ontology enrichment analysis revealed 1606 biological processes, 191 cellular components, and 373 molecular functions. Kyoto Encyclopedia of Genes and Genomes pathway analysis identified 212 signaling pathways, with significant enrichment in caffeine metabolism, bladder cancer, advanced glycation end products-receptor for advanced glycation end products signaling pathway in diabetic complications, and vascular endothelial growth factor signaling pathway. Molecular docking results showed strong binding energy between core active components and core targets. Yangxin decoction exhibits multi-component, multi-pathway, and multi-target therapeutic characteristics. It primarily regulates targets such as AKT1, tumor necrosis factor, interleukin-6, tumor protein P53, and proto-oncogene tyrosine-protein kinase Src through advanced glycation end products-receptor for advanced glycation end products, vascular endothelial growth factor, and ErbB signaling pathways, exerting anti-inflammatory, immune-regulating, and oxidative stress-inhibiting effects to alleviate MDD.

Molecular Docking Simulation↗

PubMed2003

Molecular dynamics simulations of lignin peroxidase in solution.

The dynamical and structural properties of lignin peroxidase and its Trp171Ala mutant have been investigated in aqueous solution using molecular dynamics (MD) simulations. In both cases, the enzyme retained its overall backbone structure and all its noncovalent interactions in the course of the MD simulations. Very interestingly, the analysis of the MD trajectories showed the presence of large fluctuations in correspondence of the residues forming the heme access channel; these movements enlarge the opening and facilitate the access of substrates to the enzyme active site. Moreover, steered molecular dynamics docking simulations have shown that lignin peroxidase natural substrate (veratryl alcohol) can easily approach the heme edge through the access channel.

Benzyl Alcohols↗

PubMed2026

Binding analysis of the response regulator NarL protein to the promoter of the O6-methylguanine-DNA methyltransferase (ogt) gene in Salmonella Typhimurium.

BACKGROUND: Salmonella Typhimurium (STM) is a gram-negative bacterium that causes severe gastrointestinal disorders in both animals and humans. The regulation of DNA repair genes is critical for maintaining genomic stability of the bacteria. O6-methylguanine DNA methyltransferase (Ogt), plays a vital role in repairing alkylated DNA in STM; however, the transcriptional regulation of ogt gene remains poorly characterized. Furthermore, NarL is a transcriptional regulator, involved in the pathogenesis of STM under anaerobic condition. Therefore, this study investigated the interaction between NarL protein and the promoter region of the ogt gene. METHODS: In this study, narl gene was cloned in pET32a vector and NarL protein was expressed in Escherichia coli BL21 (DE3). Subsequently, the ogt gene promoter (pogt) was selected, amplified, cloned and its activity was evaluated. Electrophoretic mobility shift assay (EMSA), isothermal titration calorimetry (ITC), molecular docking were employed to elucidate the interaction between NarL protein and ogt promoter. Furthermore, the regulatory role of NarL in ogt gene expression was validated in vivo using RT-qPCR and β-galactosidase assay. RESULTS: This study resulted that NarL protein interacts specifically with the ogt promoter, as confirmed by EMSA and ITC, with ΔG of - 9.42 kcal mol⁻¹. Furthermore, RT-qPCR and β-galactosidase assays demonstrated that deletion of narl significantly (P ≤ 0.01) decreased ogt transcript levels and promoter activity than wild Salmonella Typhimurium, whereas exogenous supplementation of recombinant NarL protein restored the expression. These findings suggest that NarL plays a potential regulatory role in ogt gene expression in response to environmental signals. CONCLUSION: These findings highlight an interaction between NarL protein and the promoter region of ogt gene in Salmonella Typhimurium, linking nitrogen metabolism with the DNA repair pathway in STM, which may contribute to the bacterial survival under nitrosative stress.

Salmonella typhimurium↗

PubMed2026

Resveratrol Attenuates Gemcitabine Resistance in Hepatocellular Carcinoma Cells by Inhibiting Thymidylate Synthase.

BACKGROUND: Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide. Gemcitabine (Gem) is a commonly used drug against HCC, but its efficacy is limited by the development of resistance. Resveratrol (Res), a natural polyphenol with antitumor activity, may reverse Gem resistance in HCC, although the mechanism remains unclear. METHODS: The effects of Res on the proliferation, apoptosis, cell cycle, and invasion of Hep3B and HuH-7 cells were assessed via cell counting kit-8 (CCK-8), clonogenic, flow cytometry, and Transwell assays, respectively. Potential Res targets were predicted by network pharmacology, and markers of HCC prognosis were identified from the cancer genome atlas (TCGA) data. The interaction between Res and thymidylate synthase (TYMS) was validated by molecular docking and dynamics simulation. A Gem-resistant HuH-7 cell line (HuH-7/GR) was established, and when these cells were treated with Res combined with Gem, the effect on Gem sensitivity was detected by CCK-8 assay, clonogenic assay, and flow cytometry. Finally, a subcutaneous nude mouse model of HCC was used to evaluate the in vivo effects of Res combined with Gem. RESULTS: Res inhibited HCC cell proliferation, induced apoptosis and G2/M arrest, and suppressed invasion in a concentration-dependent manner. Network pharmacology and TCGA analysis identified TYMS as an important target gene for Res. TYMS was highly expressed in HCC tissues and correlated with poor prognosis. Res treatment reduced TYMS expression, while molecular docking and simulation showed stable binding of Res to TYMS. TYMS levels were elevated in HuH-7/GR resistant cells. Res combined with Gem was found to reverse drug resistance, inhibit proliferation and colony formation, and induce apoptosis. The Res + Gem combination group showed the smallest tumor volume in the in vivo model. CONCLUSION: By attenuating Gem resistance through TYMS inhibition, Res holds promise as a clinically viable adjunct to Gem-based chemotherapy, offering a potential strategy to improve outcomes in HCC patients.

Resveratrol↗

PubMed2026

Gut microbiota-derived metabolites target C5AR1/KDM2A/HCAR3 axis in inflammatory bowel disease: a multi-machine learning algorithms and molecular docking study.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic recurrent disorder. Gut microbiota-derived metabolites regulate intestinal homeostasis, but their molecular mechanisms in IBD remain unclear. Current studies lack systematic "microbiota-metabolite-target" network mining with multi-method validation. This study integrates network pharmacology, three machine learning algorithms, and molecular docking to construct this regulatory network in IBD. METHODS: Transcriptome data were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using limma (p < 0.05, |log2FC| > 0.5). Weighted gene co-expression network analysis (WGCNA) with an optimal soft threshold of β = 7 was performed to identify key module genes. Candidate genes were obtained by intersecting DEGs, gut microbiota-associated genes from the gutMGene database, and WGCNA module genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to explore the functional roles of candidate genes. Core genes were identified using three machine learning algorithms (LASSO, Boruta, and SVM-RFE), followed by protein-protein interaction (PPI) network analysis. Molecular docking was performed to assess the binding affinities between hub proteins and gut microbiota-derived metabolites. RESULTS: A total of 885 DEGs were identified between the IBD and control groups, including 463 upregulated and 422 downregulated genes. WGCNA identified 280 key module genes from the purple and yellow modules. The intersection of DEGs, gut microbiota-associated genes, and WGCNA module genes yielded 19 core candidate genes. PPI network analysis combined with three machine learning algorithms jointly identified C5AR1, KDM2A, and HCAR3 as core hub genes. ROC curve analysis demonstrated that all three hub genes achieved AUC values greater than 0.7 in both the training and validation sets, indicating excellent diagnostic performance for IBD. Enrichment analysis revealed significant associations with the TNF, NF-κB, and IL-17 signaling pathways. Molecular docking confirmed stable binding of C5AR1 with 1,3-Diphenylpropan-2-Ol (-7.87 ± 0.83 kcal·mol-¹) and HCAR3 with 3-Indolepropionic Acid (-6.35 ± 0.70 kcal·mol-¹), both below -5.0 kcal·mol-¹. CONCLUSION: This study first constructs a "gut microbiota-metabolite-hub gene" axis in IBD, providing a computational framework for microbiota-targeted precision therapy, and identifying C5AR1/KDM2A/HCAR3 as computationally predicted diagnostic biomarkers and 1,3-Diphenylpropan-2-Ol/3-Indolepropionic Acid as candidate intervention molecules that warrant further experimental validation.

Molecular Docking Simulation↗

PubMed2026

Integrated network pharmacology, molecular docking, and experimental validation to reveal the potential mechanism of Ginsenoside Rg1 on chronic obstructive pulmonary disease.

Ginsenoside Rg1 (GS Rg1), a natural flavonoid exhibiting anti-inflammatory and antioxidant properties, holds significant potential for treatment chronic obstructive pulmonary disease (COPD). Nevertheless, the precise mechanisms underlying its therapeutic effects remain to be fully elucidated. This study aimed to explore the role and potential mechanism of GS Rg1 in the treatment of COPD using network pharmacology, molecular docking, and experimental validation.Targets related to GS Rg1 and COPD were screened from public databases, and the potential common targets were then imported into the STRING database to construct a protein-protein interaction (PPI) network. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis were performed to identify key signaling pathways. Molecular docking was employed to predict the binding interactions between GS Rg1 and core targets. A BEAS-2B cell model induced by lipopolysaccharide(LPS) and cigarette smoke extract(CSE) was used to explore the protective mechanisms of GS Rg1. Western blot analysis was conducted to validate the critical targets and pathways involved in the anti-COPD effects of GS Rg1. Network pharmacology analysis revealed 105 common targets between GS Rg1 and COPD. The EGFR/PI3K/AKT and EGFR/STAT3 signaling pathways were selected for further validation. GS Rg1 was demonstrated to effectively inhibit inflammation and mucus hypersecretion in vitro models of COPD. Western blot results showed that GS Rg1 treatment significantly downregulated the expression of proteins involved in the EGFR/PI3K/AKT and EGFR/STAT3 signaling pathway, consistent with the network pharmacology findings. CSE/LPS exposure induces inflammation and oxidative stress in COPD by disrupting the EGFR/PI3K/AKT and EGFR/STAT3 signaling pathways, and GS Rg1 significantly alleviates these effects, which may be partially through regulating the EGFR/PI3K/AKT and EGFR/STAT3 signaling pathway.

Ginsenosides↗

PubMed2026

Computational prediction of a multi-epitope Human Metapneumovirus vaccine candidate through integrated reverse vaccinology and pan-genomic approaches.

Human metapneumovirus (HMPV) is a primary cause of global respiratory infections yet no approved vaccine currently exists. This study computationally predicts a multi-epitope vaccine candidate using a diverse dataset of 65 HMPV sequences spanning five continents. Following the screening of lead proteins for antigenicity and virulence, fifteen highly conserved MHC-I, MHC-II and B-cell epitopes were prioritized. These were integrated with a putative L7/L12 adjuvant using optimized AAY, GPGPG, and KK linkers to design three constructs (HMPV_V1-V3). Structural validation identified HMPV-V2 as the lead candidate that exhibits a Z-score of-5.24 and 87.7% of residues in favored Ramachandran regions indicating excellent stereochemical quality and structural stability. In silico docking indicated a strong predicted binding affinity between HMPV-V2 and the TLR4 receptor (energy: -969.2). Immune simulations predicted a robust adaptive response characterized by high IgG1 titers, memory B-cell maturation, and a Th1-dominant cytokine profile. Furthermore, molecular dynamics simulations suggested exceptional structural integrity for HMPV-V2, maintaining a low RMSD of 8.213 and RMSF of 0.737 throughout the simulation. Optimized in silico cloning into the pET28a (+) vector indicated a high potential for protein expression in E. coli systems. While these findings provide a theoretically grounded blueprint for vaccine development, this study is entirely computational and lacks experimental validation. Further in vitro and in vivo testing is required to confirm the actual safety and immunogenicity of the proposed candidate.

Metapneumovirus↗

PubMed2026

Multitargeted comparative evaluation suggests 2-Aoeobenoxmide shows favourable in silico binding compared to Tucatinib against ERα, HER2, AKT1, EGFR, and PIK3CA in breast cancer.

Breast cancer is a leading cause of cancer-related morbidity and mortality globally, with the WHO reporting approximately 2.3 million new cases and 685,000 deaths annually. Drug resistance in breast cancer complicates treatment, with mutations in critical proteins contributing to therapy failure. Key oncogenic proteins involved in breast cancer progression-namely ERα (a ligand-activated nuclear receptor; PDB: 1A52) and the kinase domains of HER2 (PDB ID: 3PP0), AKT1 (PDB ID: 4EJN), EGFR (PDB ID: 4I23) and PIK3CA (PDB ID: 7R9V)-are pivotal in tumour progression and resistance mechanisms. Targeting these proteins using multitargeted therapeutic strategies may overcome resistance by disrupting key signalling pathways involved in cell proliferation, survival, and metastasis. Such combinatorial approaches promise to improve treatment efficacy and patient outcomes in cases of resistant breast cancer. In this study, we performed multitarget docking on prepared and validated protein structures against the ZINC natural compound library using HTVS, SP, and XP, with pose validation using MM-GBSA. We identified 2-Aoeobenoxmide (2-[1-(2-amino-2-oxo-ethoxy)-6-oxo-benzo[c]chromen-3-yl]oxyacetamide, ZINC134008) with docking and MM-GBSA scores ranging from -8.162 to -10.327 kcal/mol and from -47.18 to -57.62 kcal/mol, respectively, and compared the results with the FDA-approved drug Tucatinib, which exhibited lower binding affinity scores. We further evaluated pharmacokinetic properties using QikProp and electronic properties using DFT (Jaguar) and compared the descriptors of 2-Aoeobenoxmide with those of Tucatinib and with accepted reference ranges. We also performed the WaterMap for 5 nanoseconds (ns), computed various energies, interactions and hydration sites, and the comparison suggests that 2-Aoeobenoxmide shows more favourable hydration-site displacement and binding interactions than Tucatinib. Additionally, a 100 ns MD Simulation has resulted in far less deviation, fluctuations, and intermolecular interactions than Tucatinib, suggesting stable protein-ligand interactions, while the binding free energy and total complex energy computed across 0-1000 frames of the MD trajectories indicate that 2-Aoeobenoxmide is a promising in silico candidate. Importantly, because the entire study is computational, the findings should be interpreted as in silico hypotheses, and experimental validation through in vitro and in vivo assays is warranted before any clinical translation is considered.

Humans↗

PubMed2026

Proteomic regulation of anti-proliferative and anti-migratory activity by potent phytochemicals from Pistacia integerrima J.L. Steward Ex Brandis via PI3K, AKT1, and KRAS for Lung Cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the leading cause of mortality worldwide and remains a major therapeutic challenge due to high metastasis, drug resistance and limited treatments. Pistacia integerrima J.L. Steward Ex Brandis (PI) consists of flavonoids, steroids, terpenoids and phenolic compounds reported for pharmacological activities. The efficacy of potent bioactives from P. integerrima may be ascertained employing cytotoxic, antiproliferative, anti-migratory, and anti-metastatic evaluations in A549 NSCLC cells with proteomic profiling, molecular docking, and dynamics simulation study. METHODS AND RESULTS: PI EtAc produced significant dose-dependent cytotoxicity in A549 cells (100 µg/mL, p < 0.0001 in the MTT assay. There was a pronounced decrease in colony formation after treatment with EtAc, with 18.41% (p < 0.002), and markedly. Furthermore. PI EtAC markedly inhibited cell migration emphasized by wound healing and Transwell migration (p < 0.01) assays, indicating reduced metastatic migratory potential. Proteomic analysis demonstrated significant downregulation of Endoglin (CD105), KLK5 and MMP-2, indicating suppression of angiogenic and metastatic signalling pathways in the Human XL Oncology protein array. The interaction of major PI phytochemicals with key NSCLC-associated targets was recorded in Molecular docking, revealing favourable binding affinities of kaempferol, β- sitosterol, luteolin, and quercetin towards several oncogenic targets, including AKT1(- 7.6 kcal/mol), PI3K(- 9.4 kcal/mol), KRAS (- 8.5 kcal/mol) and MMP9 (- 8.1 kcal/mol). Molecular dynamics simulation confirmed the structural stability of the kaempferol -AKT1 complex throughout the 100 ns simulation. CONCLUSION: Pistacia integerrima bioactives exhibited significant anti-proliferative, anti-migratory, and anti-metastatic activities in vitro, which may provide scientific rationale identifying newer promising candidates for NSCLC.

Humans↗

PubMed1997

Inhibitors of urokinase reduce size of prostate cancer xenografts in severe combined immunodeficient mice.

Proteolytic enzymes are required to mediate tumor cell invasion and metastasis. The urokinase plasminogen activator (uPA) is commonly overexpressed by many human cancers. Therefore, uPA is a logical target to inhibit cancer invasion and metastasis. However, uPA inhibitors also reduce tumor growth. We used a mutated form of plasminogen activator inhibitor type 1 to conform a correlation between the inactivation of uPA and tumor size; we have compared these results with the action of p-aminobenzamidine and amiloride, known inhibitors of uPA. Our results show that blocking uPA by uPA inhibitors reduces tumor size in experimental animals. Our molecular simulation of docking inhibitors to the urokinase reveals that all tested small molecule inhibitors bind in proximity of uPA's specificity pocket, a critical site for future search of novel anticancer uPA inhibitors.

Amiloride↗

PubMedDate not supplied

Molecular determinants of the hanatoxin binding in voltage-gated K+-channel drk1.

The carboxyl terminus of S3 segment (S3(C)) in voltage-gated potassium channels was proposed to bear the binding site for gating modifier toxins like Hanatoxin and a helical secondary structural arrangement was suggested. Due to the lack of complete structure in high resolution for such a channel molecule, no further direct experimental data to elucidate the mechanism for their binding conformations could thus far be derived. In order to examine the putative three-dimensional structure of S3(C) and to illustrate the residues required for Hanatoxin binding, molecular simulation and docking were performed, based on the solution structure of Hanatoxin and the structural information from lysine-scanning results for S3(C) fragment. From our results, it is indicated that both hydrophobic and electrostatic interactions are utilized to stabilize the toxin binding. Detailed docking residues and appropriate orientation for binding regarding hydrophobic/-philic environments are also described. Compared with the functional data proposed by previous studies, the helical structural arrangement for the C-terminus of S3 segment in voltage-gated potassium channels can therefore be further emphasized.

Binding Sites↗

PubMed2025

Phytocompounds of Honey mesquite (Prosopis glandulosa) and Lodhra (Symplocos racemosa) in the management of COVID-19 associated rheumatoid arthritis (CARA).

COVID-19 persists globally with profound social and economic consequences, and its complex interplay with other diseases makes it a syndemic. Rheumatoid arthritis (RA), a chronic autoimmune disorder, has shown increased incidence during the pandemic, with patients displaying higher susceptibility to COVID-19. This overlap prompted the hypothesis of 'COVID-19-associated rheumatoid arthritis (CARA)'. The present study explores phytocompounds with anti-inflammatory and immunomodulatory properties as potential CARA therapeutics. Compounds from Prosopis glandulosa and Symplocos racemosa, both used in traditional medicine, were evaluated through molecular docking and simulation studies. Six inflammatory targets relevant to RA and COVID-19 -interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF), human leukocyte antigen DR4 (HLA-DR4), signal transducer and activator of transcription 4 (STAT4), and peptidyl arginine deiminase 4 (PAD4) were selected. Among the tested ligands, salidroside showed the strongest binding affinity, with energies of - 8.20 kcal/mol (IL-6), - 7.67 kcal/mol (TNF-α), - 8.53 kcal/mol (GM-CSF), - 8.80 kcal/mol (HLA-DR4), - 8.18 kcal/mol (STAT4), and - 7.91 kcal/mol (PAD4), indicating stable interactions. These findings suggest salidroside could modulate key inflammatory pathways and potentially reduce cytokine storms in COVID-19 patients. Existing RA and COVID-19 treatments often cause immunosuppression, increasing vulnerability to opportunistic infections (Datta et al in J Biomol Struct Dyn 41(8):3281-3294, 2022). Immunomodulatory phytocompounds like salidroside may offer safer, targeted alternatives without compromising immune defenses. However, this study is based on in silico analyses, and warrants in vitro and in vivo validation. Nevertheless, present work may represent an important step towards novel therapeutic strategies for COVID-19 Associated Rheumatoid Arthritis (CARA).

COVID-19↗

PubMed2002

Molecular simulation reveals structural determinants of the hanatoxin binding in Kv2.1 channels.

The carboxyl terminus of the S3 segment (S3C) in voltage-gated potassium channels was suggested to be the binding site of gating modifier toxins like hanatoxin. It has also been proposed to have a helical secondary structural arrangement. The currently available structures in high resolution for such channel molecules are restricted to regions illustrating the pore function. Therefore no further direct experimental data to elucidate the detailed mechanism for such toxin binding can be derived. In order to examine the putative three-dimensional structure of S3C and to analyze the residues required for hanatoxin binding, molecular simulation and docking were performed, based on the solution structure of hanatoxin and the structural information from mutational scanning data for the S3C fragment in Kv2.1. Our results indicate that hydrophobic and electrostatic interactions are both utilized to stabilize the toxin binding. Precise docking residues and the appropriate orientation for binding regarding amphipathic environments are also described. Compared with the functional data proposed by previous studies, the helical structural arrangement for the C-terminus of the S3 segment in voltage-gated potassium channels can therefore be further emphasized and analyzed. The possible location/orientation for toxin binding with respect to membrane distribution around the S3C segment is also discussed in this paper.

Binding Sites↗

PubMed2002

Structural influence of hanatoxin binding on the carboxyl terminus of S3 segment in voltage-gated K(+)-channel Kv2.1.

The voltage-sensing domains of voltage-gated potassium channels Kv2.1 (drk1) contain four transmembrane segments in each subunit, termed S1 to S4. While S4 is known as the voltage sensor, the carboxyl terminus of S3 (S3C) bears a gradually broader interest concerning the site for gating modifier toxins like hanatoxin and thus the secondary structure arrangement as well as its surrounding environment. To further examine the putative three-dimensional (3-D) structure of S3C and to illustrate the residues required for hanatoxin binding (which may, in turn, show the influence on the S4 in terms of changes in channel gating), molecular simulations and dockings were performed. These were based on the solution structure of hanatoxin and the structural information from lysine-scanning results for S3C fragment. Our data suggest that several basic and acidic residues of hanatoxin are electrostatically and stereochemically mapped onto their partner residues on S3C helix, whereas some aromatic or hydrophobic residues located on the same helical fragment interact with the hydrophobic patch of the toxin upon binding. Therefore, a slight distortion of the S3C helix, in a direction toward the N-terminus of S4, may exist. Such conformational change of S3C upon toxin binding is presented as a possible explanation for the observed shift in hanatoxin binding-induced gating.

Animals↗

PubMed2024

Adeno-Associated Virus Type 5 Infection via PDGFRα Is Associated With Interstitial Lung Disease in Systemic Sclerosis and Generates Composite Peptides and Epitopes Recognized by the Agonistic Immunoglobulins Present in Patients With Systemic Sclerosis.

OBJECTIVE: The etiopathogenesis of systemic sclerosis (SSc) is unknown. Platelet-derived growth factor receptors (PDGFRs) are overexpressed in patients with SSc. Because PDGFRα is targeted by the adeno-associated virus type 5 (AAV5), we investigated whether AAV5 forms a complex with PDGFRα exposing epitopes that may induce the immune responses to the virus-PDGFRα complex. METHODS: The binding of monomeric human PDGFRα to the AAV5 capsid was analyzed by in silico molecular docking, surface plasmon resonance (SPR), and genome editing of the PDGFRα locus. AAV5 was detected in SSc lungs by in situ hybridization, immunohistochemistry, confocal microscopy, and molecular analysis of bronchoalveolar lavage (BAL) fluid. Immune responses to AAV5 and PDGFRα were evaluated by SPR using SSc monoclonal anti-PDGFRα antibodies and immunoaffinity-purified anti-PDGFRα antibodies from sera of patients with SSc. RESULTS: AAV5 was detected in the BAL fluid of 41 of 66 patients with SSc with interstitial lung disease (62.1%) and in 17 of 66 controls (25.75%) (P < 0.001). In SSc lungs, AAV5 localized in type II pneumocytes and in interstitial cells. A molecular complex formed of spatially contiguous epitopes of the AAV5 capsid and of PDGFRα was identified and characterized. In silico molecular docking analysis and binding to the agonistic anti-PDGFRα antibodies identified spatially contiguous epitopes derived from PDGFRα and AAV5 that interacted with SSc agonistic antibodies to PDGFRα. These peptides were also able to bind total IgG isolated from patients with SSc, not from healthy controls. CONCLUSION: These data link AVV5 with the immune reactivity to endogenous antigens in SSc and provide a novel element in the pathogenesis of SSc.

Humans↗