Pocket Of Proteins Research Articles

DESIGN AND DISCOVERY OF LOPHINE DERIVATIVES AS MULTI-TARGETING AGENTS BY MOLECULAR DOCKING, ADMET, MD SIMULATION AND PHARMACOPHORE ANALYSIS: A COMPUTATIONAL APPROACH

Background Lophine is one of the new core moiety with substitution of three phenyl rings at 2nd, 4th, and 5th position of the imidazole. Lophine is not explored in development of drug molecules. In this research, we have designed 30 lophine derivatives with different substituted functional groups. The designed compounds were evaluated through different In-silico tools and softwares to check their properties for different biological receptors. Methods Molecular docking study was carried out on different receptors i.e. EGFR for anti-cancer, COX-1, and COX-2 for anti-inflammatory, fungal oxidoreductase for anti-fungal, bacterial DNA gyrase for anti-bacterial and TNF-α, which co-relates different type of inflammatory diseases. Further, ADMET of the top docked compounds were carried out in SwissADME and ProTox-II webserver. The MD simulation was carried out to check the stability of the compounds inside the binding pocket of the different proteins. Finally, the common pharmacophore was generated by PharmaGist web server. Results The molecular docking results revealed that the SAP-28 has significant binding energies -9.8, -9.6 and -10.0 kcal/mol against EGFR, fungal oxidoreductase, and TNF-α receptors respectively. SAP-26 has potent interaction -9.8 and -11.0 kcal/mol against EGFR and COX-2 receptors respectively. Whereas, SAP-25 and SAP-19 showed the best interaction for bacterial DNA gyrase (-8.9 kcal/mol) and COX-1 receptor (-9.7 kcal/mol) respectively. To enhance the acceptability top docked compounds, the ADME parameters along with toxicity analysis were carried out where all the compounds showed acceptable results. Furthermore, the stability of the protein-ligand complexes were determined by a 100 ns MD simulation analysis and compounds were found stable. The common pharmacophore was generated with the help of the top compounds in the PharmaGist web server. Discussion This In-silico study established that, various substitution on the phenyl ring present in the 2nd position of the imidazole such as 2-hydroxy, 2-methyl, 3-methyl, 4-pyridinyl etc. governing their ability to interact with diverse targets. The compound can contribute a major role in the development of different leads in future.

In-vitro enzyme inhibition, kinetics, molecular docking and dynamics simulation approaches to decoding the mechanism of Ficus virens in cholinesterase inhibition

In the current study, we investigate the bioactive potentials and mode of action of Ficus virens bark (FVB) extract against cholinesterase enzymes, via in-vitro cell-free cholinesterase inhibition kinetics, molecular docking, ADMET and dynamic simulation. Our results illustrated that FVBM extract showed better DPPH-free radical scavenging activity (IC50 = 17.8 ± 0.46 µg/ml) and AChE inhibitory ability (IC50 = 37.2 ± 0.43 µg/ml). Kinetics study explored the mixed inhibition of AChE enzyme by FVBM extract. Furthermore, molecular docking demonstrates that compounds Diethyl Phthalate and Dinopol NOP present in FVBM extract have good ΔG: −8.6 kcal/mol and Ki; 2.01 × 106 M−1 for AChE enzyme than BuChE enzyme (ΔG: −7.6 and Ki: 3.72 × 105 M−1). A simulation study of 200 ns of best two hits and Tacrine confirms that these compounds remained inside the binding pocket of proteins and formed a stable protein-ligand complex via interacting with key residue. Further studies could provide a better understanding of the therapeutic potential of these promising compounds.

Green, facile synthesis and evaluation of unsymmetrical carbamide derivatives as antimicrobial and anticancer agents with mechanistic insights

A very practical method for the synthesis of unsymmetrical carbamide derivatives in good to excellent yield was presented, without the need for any catalyst and at room temperature. Using a facile and robust protocol, fifteen unsymmetrical carbamide derivatives (9–23) bearing different aliphatic amine moieties were designed and synthesized by the reaction of secondary aliphatic amines with isocyanate derivatives in the presence of acetonitrile as an appropriate solvent in good to excellent yields. Trusted instruments like IR, mass spectrometry, NMR spectra, and elemental analyses were employed to validate the purity and chemical structures of the synthesized compounds. All the synthesized compounds were tested as antimicrobial agents against some clinically bacterial pathogens such as Salmonella typhimurium, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Compounds 15, 16, 17, 19 and 22 showed potent antimicrobial activity with promising MIC values compared to the positive controls. Moreover, compounds 15 and 22 provide a potent lipid peroxidation (LPO) of the bacterial cell wall. On the other hand, we investigated the anti-proliferative activity of compounds 9–23 against selected human cancerous cell lines of breast (MCF-7), colon (HCT-116), and lung (A549) relative to healthy noncancerous control skin fibroblast cells (BJ-1). The mechanism of their cytotoxic activity has been also examined by immunoassaying the levels of key anti- and pro-apoptotic protein markers. The results of MTT assay revealed that compounds 10, 13, 21, 22 and 23 possessed highly cytotoxic effects. Out of these, three synthesized compounds 13, 21 and 22 showed cytotoxicity with IC50 values (13, IC50 = 62.4 ± 0.128 and 22, IC50 = 91.6 ± 0.112 µM, respectively, on MCF-7), (13, IC50 = 43.5 ± 0.15 and 21, IC50 = 38.5 ± 0.17 µM, respectively, on HCT-116). Cell cycle and apoptosis/necrosis assays demonstrated that compounds 13 and 22 induced S and G2/M phase cell cycle arrest in MCF-7 cells, while only compound 13 had this effect on HCT-116 cells. Furthermore, compound 13 exhibited the greatest potency in inducing apoptosis in both cell lines compared to compounds 21 and 22. Docking studies indicated that compounds 10, 13, 21 and 23 could potentially inhibit enzymes and exert promising antimicrobial effects, as evidenced by their lower binding energies and various types of interactions observed at the active sites of key enzymes such as Sterol 14-demethylase of C. albicans, Dihydropteroate synthase of S. aureus, LasR of P. aeruginosa, Glucosamine-6-phosphate synthase of K. pneumenia and Gyrase B of B. subtilis. Moreover, 13, 21, and 22 demonstrated minimal binding energy and favorable affinity towards the active pocket of anticancer receptor proteins, including CDK2, EGFR, Erα, Topoisomerase II and VEGFFR. Physicochemical properties, drug-likeness, and ADME (absorption, distribution, metabolism, excretion, and toxicity) parameters of the selected compounds were also computed.

Synthesis, pharmacological evaluation, and in silico study of new 3-furan-1-thiophene-based chalcones as antibacterial and anticancer agents

New 3-furan-1-thiophene-based chalcones were synthesized, characterized and pharmacologically evaluated as antibacterial and anticancer agents against two bacterial species; Gram-positive (Streptococcus pyogenes) and Gram-negative (Pseudomonas aeruginosa). All tested final compounds were active against the two bacterial species; S. pyogenes and P.aeruginosa. Especially compound AM4 showed large inhibition zone (27.13 and 23.30 mm), respectively. Using the DPPH assay, the new chalcones were evaluated for their free radical scavenging activity and found to reach up to 90 %, accomplished at a test concentration of 200 μg/mL. Furthermore, the chalcone derivatives were investigated against two breast cell lines; MCF-7 (cancerous) and MCF-10A (non-cancerous). Compound AM4 showed potent anticancer activity (IC50 = 19.354 μg/mL) in comparison to the other tested chalcone derivatives. In silico study was achieved using the PyRx AutoDock Vina software (0.8) to study the interaction types between the new hits and the binding sites of targeted proteins; glucosamine-6-phosphate synthase and tubulin, the target for antibacterial and anticancer drugs, respectively. Based on the molecular docking results the tested chalcones bind to the active pocket of the respective proteins, which support the in vitro results. In conclusion, 3-furan-1-thiophene-based chalcones could serve as new hits in the discovery of novel anticancer and/or antibacterial drugs.

Discovery of N-(4-((6-(3,5- Dimethoxyphenyl)-9H-purine derivatives as irreversible covalent FGFR inhibitors

Fibroblast growth factor receptor (FGFR) is an attractive target for cancer therapy, but existing FGFR inhibitors appear to hardly meet the demand for clinical application. Herein, a number of irreversible covalent FGFR inhibitors were designed and synthesized by selecting several five- and six-membered azaheterocycles as parent scaffold with different substituents to take over the hydrophobic region in the active pocket of FGFR proteins. Among the resulting target compounds, III-30 showed the most potent effect on enzyme activity inhibition and anti-proliferative activity against the tested cancer cell lines. Significantly, III-30 could inhibit the enzyme activity by achieving irreversible covalent binding with FGFR1 and FGFR4 proteins. It could also regulate FGFR-mediated signaling pathway and mitochondrial apoptotic pathway to promote cancer cell apoptosis and inhibit cancer cell invasion and metastasis. Moreover, III-30 had a good metabolic stability and showed relatively potent anti-tumor activity in the MDA-MB-231 xenograft tumor mice model.

Abstract LB159: Discovery of HP560, a novel BET inhibitor for the treatment of myelofibrosis

Abstract Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by defective clonal hematopoiesis, bone marrow fibrosis, splenomegaly, severe anemia, and the propensity for transformation to acute myeloid leukemia (AML). Inhibitors targeting JAKs (Janus kinases) have revolutionized the treatment of MF, but are limited by modest efficacy or acquired resistance after prolonged treatment. Here, we report a novel inhibitor, HP560 that targets BET (bromodomain and extra-terminal) proteins and shows promising therapeutic activities against MF and AML. Through engaging the bromodomain pocket of BET proteins in a competitive manner with acetylated histones, HP560 causes the disruption of BET proteins from chromatin. HP560 has high binding affinities for all BET proteins and strong anti-proliferative activity as well as synergistic anti-proliferative effect in combination with ruxolitinib, a JAK1/2 inhibitor. In an MF cell line derived tumor xenograft (CDX) mouse model, HP560 prolongs survival and improves splenomegaly and anemia, and these effects are enhanced when combined with ruxolitinib. HP560 also significantly and dose-dependently inhibits tumor growth in an AML CDX mouse model. Together, HP560 is a potent pan-BET inhibitor and can be developed as a monotherapy or in combination with a JAK inhibitor for the treatment of MF. HP560 structure will not be disclosed. Citation Format: Jing Li, Lei Fan, Hongwei Yuan, Yongxu Huo, Hua Yu, Fei Wang, Xinghai Li. Discovery of HP560, a novel BET inhibitor for the treatment of myelofibrosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB159.

Design, synthesis and biological evaluation of matrine contains benzimidazole derivatives as dual TOPOI and PARP inhibitors for cancer therapy

TOPOI inhibitors have long been a focal point in the research and development of antitumor drugs. PARP-1 plays a crucial role in repairing DNA damage induced by TOPOI inhibitors. Thus, concurrent inhibition of TOPOI and PARP-1 has the potential to augment drug activity. Matrine, characterized by low toxicity and good water solubility, offers advantageous properties. In this investigation, a series of benzimidazole matrine derivatives were designed and synthesized using matrine as the lead compound with the aim of developing dual inhibitors targeting both TOPOI and PARP-1. Among these derivatives, Compound B6 exhibited potent inhibitory effects on PARP-1 and TOPOI, effectively suppressing cancer cell proliferation and migration. Mechanistic assessments revealed that B6 induced DNA damage in HGC-27 cells, leading to G0/G1 cell cycle arrest and significant apoptosis. Molecular docking experiments demonstrated that B6 can effectively enter the active pocket of target proteins, where it forms stable hydrogen bonds with amino acid residues. In vivo, experiments demonstrated that B6 exhibited antitumor activity comparable to that of the positive control drug. The tumor growth inhibition rates (TGIs) for irinotecan, B6 and matrine were 87.0%, 75.4% and 9.7%, respectively. Importantly, B6 demonstrated lower toxicity than the positive control drug. Our findings suggest that TOPOI and PARP-1 may represent potential targets for matrine and B6 emerges as a promising candidate for cancer therapy.

Abstract 7264: OPN-9840, a non-covalent potent pan-TEAD inhibitor, exhibits single agent efficacy in preclinical malignant mesothelioma models

Abstract The Hippo pathway regulates critical cellular processes during development. In ~10% of human cancers, Hippo pathway dysregulation results in YAP/TAZ overactivation and increased TEAD-dependent transcription that promotes tumor growth and therapy resistance - often by supporting drug-tolerant persister survival. In 40% of malignant mesotheliomas (MM), neurofibromatosis 2 (NF2) gene mutations inactivate the Merlin protein, an upstream negative regulator of TEAD. Preclinical studies indicate high TEAD dependency in NF2-mutant MM. We have discovered an array of potent covalent and non-covalent small molecule inhibitors that occupy the palmitate-binding pocket of TEAD proteins, with varying paralog selectivity profiles. OPN-9840 is an oral non-covalent pan-TEAD inhibitor displaying dose-dependent and on-target in vitro and in vivo efficacy for NCI-H226, an NF2-mutant MM cell line. OPN-9840 showed equivalent binding in thermal shift assays (10°C delta Tm) for depalmitoylated TEAD1-4 proteins, and blocked TEAD reporter activity (IC50 100nM) and NCI-H226 cell growth (IC50 400nM). In an NCI-H226 xenograft model, OPN-9840 dosed orally for 14 days exhibited dose-dependent tumor growth inhibition (TGI) from 5 to 50 mg/kg PO (88 to >100% TGI) with tumor regression in the 15 (2/8 mice) and 50 mg/kg (4/8 mice) dose groups. qPCR of OPN-9840-treated tumors confirmed 50-70% downregulation of canonical TEAD targets, CTGF and CYR61. OPN-9840 shows a favorable safety profile, including a lack of cytotoxicity (IC50>50µM) in HEK293T and HepG2 cells. Additionally, OPN-9840 caused no body weight loss in the NCI-H226 xenograft model following 14 days of dosing. In vitro evaluation of OPN-9840 in the blood-brain barrier (BBB) specific parallel artificial membrane permeability assay exhibited high BBB penetration potential (-Log Pe = 4.7). High oral exposure was achieved at all dose levels (AUC0-24 > 100,000 h•ng/mL) after 14 days in the NCI-H226 study. We next investigated synergy between TEAD inhibition and targeted therapy in MM. Combined treatment of one of our pan-TEAD covalent compounds, OPN-9652 (from a separate chemical series to OPN-9840), at 50 mg/kg with 1 mg/kg trametinib resulted in NCI-H226 xenograft tumor regression (130% TGI) whereas trametinib alone only led to decreased tumor growth (74% TGI). RNA-Seq of treated tumors revealed that OPN-9652 and trametinib synergistically inhibited TEAD downstream target genes, including ANKRD1 and CTGF. OPN-9652 as a single agent caused significant downregulation of E2F targets, such as MYC and TP53, suggesting decreased proliferation. In summary, OPN-9840 is a potent pan-TEAD inhibitor that shows monotherapy efficacy in MM. As we observed synergy between another pan-TEAD inhibitor, OPN-9652, with trametinib, we are exploring synergy of OPN-9840 with additional targeted therapies in tumor types beyond MM. Citation Format: Pan-Yu Chen, Bernice Matusow, James Tsai, Peipei Li, Hoa Nguyen, Gaston Habets, Gideon Bollag, Somenath Chowdhury. OPN-9840, a non-covalent potent pan-TEAD inhibitor, exhibits single agent efficacy in preclinical malignant mesothelioma models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7264.

Synthesis and biological activity of 11-Oxygenated and heterocyclic estrone analogs in pancreatic cancer monolayers and 3D spheroids

Pancreatic Ductal Adenocarcinoma (PDAC), representing over 90 % of pancreatic cancer diagnoses, is an aggressive disease with survivability among the worst of all cancers due to its difficulty in detection and its high metastatic properties. Current therapies for PDAC show limited success at extending life expectancies, primarily due to cancer resistance and lack of patient-specific targeted therapies. This work highlights the design and evaluation of estrone-derived analogs with both heterocyclic side-chain functionality and 11-oxygenated functionality for use in pancreatic cancer. First-round heterocyclic analogs show preliminary promise in AsPC-1 and Panc-1 cell lines, with IC50 values as low as 10.16 ± 0.83 µM. Their success, coupled with design choices from other studies, led to the synthesis of novel 11-hydroxyl and 11-keto estrone analogs that show potent in-vitro toxicity against various pancreatic cancer models. The three most cytotoxic analogs, KA1, KA2, and KA9 demonstrated low micromolar activities in both MTT and CellTiter assays in three pancreatic cancer cell lines: AsPC-1, Panc-1, and BxPC-3, as well as in a co-culture of Panc-1 and pancreatic stellate cells. IC50 values for KA9 (4.17 ± 0.90, 5.28 ± 1.87, and 5.70 ± 0.65 µM respectively) shows consistency in all cell lines tested. KA9 is also able to cause an increase in caspases 3 and 7 activity, key markers for apoptosis, at non-cytotoxic concentrations. Additional work was performed by generating 3D pancreatic cancer spheroids to better modulate the pancreatic tumor microenvironment, and KA9 continued to show the best IC50 values (21.0 and 24.3 µM) in both cell types tested. KA9 was also able to prevent the growth of spheroids whereas the standard chemotherapy, Gemcitabine, could not, suggesting that it may be a potent analog for future development of treatments. Molecular dynamic simulations were also performed to confirm biological findings and uncovered that KA9′s preferential binding location is in the active site pocket of key proteins involved in cytotoxicity.

Direct interaction of Su(var)2-10 via the SIM-binding site of the Piwi protein is required for transposon silencing in Drosophila melanogaster.

Nuclear Piwi/Piwi-interacting RNA complexes mediate co-transcriptional silencing of transposable elements by inducing local heterochromatin formation. In Drosophila, sumoylation plays an essential role in the assembly of the silencing complex; however, the molecular mechanism by which the sumoylation machinery is recruited to the transposon loci is poorly understood. Here, we show that the Drosophila E3 SUMO-ligase Su(var)2-10 directly binds to the Piwi protein. This interaction is mediated by the SUMO-interacting motif-like (SIM-like) structure in the C-terminal domain of Su(var)2-10. We demonstrated that the SIM-like structure binds to a special region found in the MID domain of the Piwi protein, the structure of which is highly similar to the SIM-binding pocket of SUMO proteins. Abrogation of the Su(var)2-10-binding surface of the Piwi protein resulted in transposon derepression in the ovary of adult flies. Based on our results, we propose a model in which the Piwi protein initiates local sumoylation in the silencing complex by recruiting Su(var)2-10 to the transposon loci.

Tubulin-gene Mutation in Drug Resistance in Helminth Parasite: Docking and Molecular Dynamics Simulation Study

Background: Drug resistance is an important phenomenon in helminth parasites. Microtubules are among the key chemotherapeutic targets, mutations of which lead to drug resistance. Objectives: The present study investigated the role of F167Y, E198A, and F200Y mutations in β- tubulin protein and their effect on albendazole binding. Methods: Brugia malayi β-tubulin protein models were generated using the SwissModel platform by submitting amino acid sequences. Mutations were carried out at amino acid sequences by changing F167Y, E198A, and F200Y. All the model proteins (one wild and three mutated) were docked with the anthelmintic drug albendazole using AutoDock vina-1.1.5. Docking complexes were further investigated for their binding stability by a Molecular Dynamic Simulation study using Gromacs-2023.2. The binding free energies of protein-ligand complexes were analyzed using the MM/PBSA package. Results: The docking study observed decreased ligand binding affinity in F167Y and E198A mutant proteins compared to wild proteins. MD simulation revealed the overall structural stability of the protein complexes during the simulation period. The simulation also observed more stable binding of albendazole in the active pocket of mutant proteins compared to wild-type proteins. Like ligand RMSD, wild-type protein also showed higher amino acid residual flexibility. The flexibility indicates the less compactness of wild β-tubulin protein complexes compared to mutant proteinligand complexes. Van der Waals and electrostatic interactions were found to be the major energy in protein-ligand complexes. However, due to higher solvation energy, wild-type protein showed more flexibility compared to others. Conclusion: The study, therefore, concludes that mutations at positions 167 and 198 of the β- tubulin protein contribute to resistance to albendazole through weakened binding affinity. However, the binding of albendazole binding to the proteins leads to structures becoming more stable and compact.

GC-MS Screening of Adiantum lunulatum Burm. F Phytochemicals and Interaction with COX-2, TRPV1, and TRPC3 Proteins-bioinformatics Approach

Background:The Adiantum lunulatum is a medicinally important pteridophyte used to treat inflammatory-related diseases. The phytochemical profile of this plant is poorly investigated.Objective:Here, we screened the nonpolar phytochemicals and their interactions with cyclooxygenase 2 (COX-2) enzyme (inflammation), transient receptor potential cation channel V member 1 (TRPV1), and transient receptor potential channel 3 (TRPC3) receptors (pain).Methods:The identification and molecular docking analysis used gas chromatography-mass spectrometry (GC-MS), AutoDock Vina, and BIOVIA discovery studio visualizer 2020. The online computer tools Swiss ADME and admetSAR predicted these compounds' bioavailability and toxicity.Results:GC-MS analysis detected the 12 different compounds. Five compounds with high similarity to mass spectrum were selected for molecular docking. This includes 2, 4 di-tert-butylphenol; n-hexadecanoic acid (palmitic acid); 2 pentadecanone, 6, 10, 14-trimethyl-; Quinoline 1, 2 dihydro 2, 2, 4 trimethyl and 3, 7, 11, 15-tetramethyl hexadec 2-en-1-yl acetate. These compounds showed interaction with the binding pocket of COX-2, TRPV1, and TRPC3 proteins. This interaction with enzyme and receptor activity causes a reduction in inflammatory pathogenesis.Conclusion:This study enhances our fundamental knowledge of biologically important volatile phytochemicals in Adiantum lunulatum dichloromethane extract and its possible effects in reducing inflammatory responses.

Spectroscopic, electronic properties analysis for 2, 6-Bis (phenylamino)-4-(iminophenyl) benzoquinone molecule and molecular docking clarification for its anticancer activity detected by strong inhibition of NQO1 enzyme

Quinone compounds have been the subject of extensive research due to their remarkable efficiency and prospective use as drugs and in a variety of fields. In this study, we report the spectroscopic characterization, electronic structure, ADMET evaluation, and molecular docking assessment of 2,6-Bis(phenylamino)-4-(iminophenyl)benzoquinone as an anticancer drug. By using DFT investigations, the vibrational wavenumbers were calculated and utilized to assign vibrational bands, which were found to be in good accordance with the experimentally observed data. The analysis of the UV-Vis spectra revealing an absorption peak from electronic transitions HOMO→LUMO at 547 nm is found to be in good conformity with its experimental value. The HOMO and LUMO frontier molecular orbitals and their associated energies highlighted the mechanism of charge transfer within the molecule and revealed a small energy gap. The chemically reactive sites identified by the MEP surface helped predict the spots of the molecule's biological activity. According to NBO analysis, the π C9-C10 → π* C11-C12 interaction has the maximum energy stability with 23.74 Kcal/mol., due to π electron delocalization within the ring. At the same level of theory, third-order NLO polarizability was found to be 4-fold stronger than the third-order of P-NA (a prototype NLO molecule). The potential for a safe oral bioavailability drug was identified by computing ADMET parameters and evaluating drug-likeness based on Lipinski's rule of five. The molecular docking study found that the molecule binding to NQO1 receptor protein with superior binding energy -8.69 kcal/mol than previously studied Quinone derivatives. Additionally, molecular dynamics simulations were performed to test the dynamic behavior of the ligand-NQO1 complex. The complex was stable in the binding pocket of the receptor proteins, according to the analysis of the simulation outcomes such as RMSD and RMSF. These results suggests using this molecule as a potential anticancer drug due to its high capability to inhibit the NQO1 enzyme.

A comprehensive computational approach for the identification of structure-based potential pharmacological candidates as selective AKR1B1 and AKR1B10 inhibitors: repurposing of purine alkaloids for the treatment of cancer

Significant metabolic pathways have been linked to AKR1B1 and AKR1B10. These enzymes are crucial biological targets in the therapy of colon cancer. In the past several decades, drug repurposing has gained appeal as a time and cost-efficient strategy for providing new indications for existing drugs. The structural properties of the plant-based alkaloidal drugs theobromine and theophylline were examined using density functional theory (DFT) computations, where the B3LYP/SVP method was used to quantify the dipole moment, polarizability, and optimization energy. Optimized structures obtained through DFT studies were docked inside the active pocket of target proteins to evaluate their inhibitory potential. Moreover, molecular dynamic simulation provides significant insight into a dynamic view of molecular interactions. The findings of current revealed theobromine and theophylline as strong AKR1B1 and AKR1B10 inhibitors, respectively. In addition, the anti-cancer potential of theophylline and theobromine was validated by targeting various tumor proteins, i.e. NF-κB, cellular tumor antigen P53 and caspase-3 using a molecular docking approach. Theobromine was found to be strongly interacted with NF-κB and caspase-3, whereas theophylline potentially inhibited cellular tumor antigen P53. In addition, the ADMET characteristics of theobromine and theophylline were identified, confirming their drug-like capabilities. These results should open the way for further experimental validation and structure-based drug design/repurposing of AKR1B1/AKR1B10 inhibitors for the treatment of colon cancer and associated malignancies. Communicated by Ramaswamy H. Sarma

The Potential Mechanisms of Cinobufotalin Treating Colon Adenocarcinoma by Network Pharmacology.

Network pharmacology, as a novel way using bioinformatics to explore drug targets and interactions in cancer, broadens our understanding of drug action, thereby facilitating drug discovery. Here, we utilized network pharmacology to explore the role and mechanism by which cinobufotalin functions in colon adenocarcinoma (COAD). We found that cinobufotalin represses the growth and proliferation of colon cancer cells, and integrated public databases for targets reported to be associated with COAD, together with those predicted to be targets of cinobufotalin. Targets overlapped between COAD-associated proteins and cinobufotalin target proteins were used to filter candidate targets of cinobufotalin in COAD. The following proteins were thought to occupy a key position in COAD-cinobufotalin target networks: SRC, PIK3R1, MAPK1, PIK3CA, HSP90AA1, CTNNB1, GRB2, RHO1, PTPN11, and EGFR. The networks regulated by cinobufotalin were involved mainly in extracellular signal stimulation and transduction, including MAPK signaling pathway, PI3K-AKT signaling pathway, and JAK-STAT signaling pathway. Besides, transcriptome sequencing results also indicated that cinobufotalin inhibits the response of colon cancer cells to extracellular stimulation and promotes cell apoptosis. Molecular docking results showed that cinobufotalin matches in the pocket of the top candidate cinobufotalin target proteins (SRC, PIK3R1, MAPK1 and PIK3CA). These findings demonstrate cinobufotalin can be developed as potential anti-cancer therapeutics.

In silico comparative structural and compositional analysis of glycoproteins of RSV to study the nature of stability and transmissibility of RSV A.

The current scenario of COVID-19 makes us to think about the devastating diseases that kill so many people every year. Analysis of viral proteins contributes many things that are utterly useful in the evolution of therapeutic drugs and vaccines. In this study, sequence and structure of fusion glycoproteins and major surface glycoproteins of respiratory syncytial virus (RSV) were analysed to reveal the stability and transmission rate. RSV A has the highest abundance of aromatic residues. The Kyte–Doolittle scale indicates the hydrophilic nature of RSV A protein which leads to the higher transmission rate of this virus. Intra-protein interactions such as carbonyl interactions, cation–pi, and salt bridges were shown to be greater in RSV A compared to RSV B, which might lead to improved stability. This study discovered the presence of a network aromatic–sulphur interaction in viral proteins. Analysis of ligand binding pocket of RSV proteins indicated that drugs are performing better on RSV B than RSV A. It was also shown that increasing the number of tunnels in RSV A proteins boosts catalytic activity. This study will be helpful in drug discovery and vaccine development.

Comparison of carbohydrate ABC importers from Mycobacterium tuberculosis

BackgroundMycobacterium tuberculosis, the etiological agent of tuberculosis, has at least four ATP-Binding Cassette (ABC) transporters dedicated to carbohydrate uptake: LpqY/SugABC, UspABC, Rv2038c-41c, and UgpAEBC. LpqY/SugABC transporter is essential for M. tuberculosis survival in vivo and potentially involved in the recycling of cell wall components. The three-dimensional structures of substrate-binding proteins (SBPs) LpqY, UspC, and UgpB were described, however, questions about how these proteins interact with the cognate transporter are still being explored. Components of these transporters, such as SBPs, show high immunogenicity and could be used for the development of diagnostic and therapeutic tools. In this work, we used a phylogenetic and structural bioinformatics approach to compare the four systems, in an attempt to predict functionally important regions.ResultsThrough the analysis of the putative orthologs of the carbohydrate ABC importers in species of Mycobacterium genus it was shown that Rv2038c-41c and UgpAEBC systems are restricted to pathogenic species. We showed that the components of the four ABC importers are phylogenetically separated into four groups defined by structural differences in regions that modulate the functional activity or the interaction with domain partners. The regulatory region in nucleotide-binding domains, the periplasmic interface in transmembrane domains and the ligand-binding pocket of the substrate-binding proteins define their substrates and segregation in different branches. The interface between transmembrane domains and nucleotide-binding domains show conservation of residues and charge.ConclusionsThe presence of four ABC transporters in M. tuberculosis dedicated to uptake and transport of different carbohydrate sources, and the exclusivity of at least two of them being present only in pathogenic species of Mycobacterium genus, highlights their relevance in virulence and pathogenesis. The significant differences in the SBPs, not present in eukaryotes, and in the regulatory region of NBDs can be explored for the development of inhibitory drugs targeting the bacillus. The possible promiscuity of NBDs also contributes to a less specific and more comprehensive control approach.

Repurposing of available antiviral drugs against SARS-CoV-2 by targeting crucial replication machinery proteins

Background and objectives The newly emerged severe acute respiratory syndrome coronavirus is spreading worldwide rapidly with increasing incidence rates. Due to lack of effective treatments and vaccines, various drug repurposing studies are being developed. Searching for available antiviral drug libraries is the best and fast option to advance to clinical trials and spread their application among infected patients. Materials and methods Molecular docking study was performed utilizing AutoDock 4.2 system and Discovery Studio 4.5, which were utilized to predict the activity pocket of the target proteins. Results and conclusion The results found that the interacting affinities resulted from the molecular simulation of 3CL protease with ligands Ledipasvir, Sofosbuvir, Ribavirin, Galidesivir, Tenofovir, and Remdesivir were −7.2, −7.4, −7.2, −6.3, −6.1 and −6.6 kcal/mol, respectively. Similarly, the interacting energies obtained from the docking of RNA helicase with ligands were −7.9, −7.4, −6.4, −7.9, −6.2, and −6.9 kcal/mol. Also, the binding energies obtained from the docking of 3′-5′ exoribonuclease with ligands were −10.6, −10.1, −6.5, −7.1, −6.1, and −9.3 kcal/mol. Finally, the binding energies score from the docking of the RNA-dependent RNA polymerase with ligands was −9.6, −6.9, −6.2, −6.6, −6.7, and −6.4 kcal/mol. Based on the binding energy score and docking result, Ledipasvir and Sofosbuvir have a higher affinity of the drug molecule such as against RNA-dependent RNA polymerase, exonuclease, and 3CL protease. Besides, Ledipasvir and Galidesivir show prominent binding interaction with severe acute respiratory syndrome coronavirus RNA helicase. The results are promising for evaluated drugs especially Ledipasvir and Sofosbuvir and could be useful in emergency treatment of coronavirus disease 2019 patients.

New Insights Into Structure and Function of TIFY Genes in Zea mays and Solanum lycopersicum: A Genome-Wide Comprehensive Analysis.

The TIFY gene family, a key plant-specific transcription factor (TF) family, is involved in diverse biological processes including plant defense and growth regulation. Despite TIFY proteins being reported in some plant species, a genome-wide comparative and comprehensive analysis of TIFY genes in plant species can reveal more details. In the current study, the members of the TIFY gene family were significantly increased by the identification of 18 and six new members using maize and tomato reference genomes, respectively. Thus, a genome-wide comparative analysis of the TIFY gene family between 48 tomato (Solanum lycopersicum, a dicot plant) genes and 26 maize (Zea mays, a monocot plant) genes was performed in terms of sequence structure, phylogenetics, expression, regulatory systems, and protein interaction. The identified TIFYs were clustered into four subfamilies, namely, TIFY-S, JAZ, ZML, and PPD. The PPD subfamily was only detected in tomato. Within the context of the biological process, TIFY family genes in both studied plant species are predicted to be involved in various important processes, such as reproduction, metabolic processes, responses to stresses, and cell signaling. The Ka/Ks ratios of the duplicated paralogous gene pairs indicate that all of the duplicated pairs in the TIFY gene family of tomato have been influenced by an intense purifying selection, whereas in the maize genome, there are three duplicated blocks containing Ka/Ks > 1, which are implicated in evolution with positive selection. The amino acid residues present in the active site pocket of TIFY proteins partially differ in each subfamily, although the Mg or Ca ions exist heterogeneously in the centers of the active sites of all the predicted TIFY protein models. Based on the expression profiles of TIFY genes in both plant species, JAZ subfamily proteins are more associated with the response to abiotic and biotic stresses than other subfamilies. In conclusion, globally scrutinizing and comparing the maize and tomato TIFY genes showed that TIFY genes play a critical role in cell reproduction, plant growth, and responses to stress conditions, and the conserved regulatory mechanisms may control their expression.

A Cyclic Dipeptide from Marine Fungus Penicillium chrysogenum DXY-1 Exhibits Anti-quorum Sensing Activity.

Bacterial quorum sensing (QS) is anticipated as a new potential target for the development of antimicrobial drugs. An anti-QS substance against Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PA01 has been isolated and purified from the crude extracts of the marine fungus Penicillium chrysogenum DXY-1, and the accurate structure was identified as cyclo(l-Tyr-l-Pro). This cyclic dipeptide at sub-minimum inhibitory concentration can decrease the QS-regulated violacein production of C. violaceum CV026 by 79% and QS-mediated pyocyanin production, proteases, and elastase activity of P. aeruginosa PA01 by 41%, 20%, and 32%, respectively. In addition, it can also destroy the biofilm formation and decrease QS gene expression of P. aeruginosa PA01. Molecular docking was further performed, and the obtained data indicated that this dipeptide blocks the effect of QS autoinducers through competitive binding to the same pocket of the receptor proteins. We expect this anti-QS cyclic dipeptide to be a potential pro-drug treating drug-resistant P. aeruginosa infections, and these findings could relieve the alarming problem of microbial resistance to antimicrobial drugs.