Molecular-docking study of malaria drug target enzyme transketolase in Plasmodium falciparum 3D7 portends the novel approach to its treatment

Computational Development of Transmission-Blocking Vaccine Candidates Based on Fused Antigens of Pre- and Post-fertilization Gametocytes Against Plasmodium falciparum

Plasmodium falciparum is the most fatal species of malaria parasites in humans. Attempts at developing vaccines against the malaria parasites have not been very successful even after the approval of the RTS, S/AS01 vaccine. There is a continuous need for more effective vaccines including sexual-stage antigens that could block the transmission of malaria parasites between mosquitoes and humans. Low immunogenicity, expression, and stability are some of the challenges of transmission-blocking vaccine (TBV). This study was designed to computationally identify TBV candidates based on fused antigens by combining highly antigenic peptides from prefertilization (Pfs230, Pfs48/45) and postfertilization (Pfs25, Pfs28) gametocytes. The peptides were selected based on their antigenicity, nonallergenicity, and lack of similarity with the human proteome. Two fused antigens vaccine candidates (FAVCs) were constructed using Flagellin Salmonella enterica (FAVC-FSE) and Cholera toxin B (FAVC-CTB) as adjuvants. The constructs were evaluated for their physicochemical properties, structural stability, immunogenicity, and potential to elicit cross-protection across multiple Plasmodium species. The results yielded antigenic peptides, with antigenicity scores between 0.7589 and 1.1821. The structural analysis of FAVC-FSE and FAVC-CTB showed a Z-score of -6.70 and -4.79, a Ramachandran plot of 96.94% and 94.86% with overall quality of 94.20% and 89.85%, respectively. The FAVCs contained CD8+, CD4+, and linear B-cell epitopes with antigenicity scores between 1.2089 and 2.8623, 0.5663 and 2.4132, and 1.5196 and 2.2212, respectively. Each FAVC generated 6 conformational B-cells. High population coverage values were recorded for the FAVCs. The ability of the FAVCs to trigger immune response was evaluated through an in silico immune stimulation. The low-binding interaction energy that resulted from molecular docking and dynamics simulations showed a strong affinity of FAVCs to Toll-like receptor 5 (TLR5). The results indicate that the FAVC-FSE vaccine candidate is more promising to interrupt P falciparum transmission and provides a baseline for experimental validation.

Idiopathic Pulmonary Fibrosis: In Silico Therapeutic Potential of Doxycycline, Pirfenidone, and Nintedanib, and the Role of Next-Generation Phenomics in Drug Discovery

Innovation in drug discovery for human diseases stands to benefit from systems science and next-generation phenomics approaches. An example is idiopathic pulmonary fibrosis (IPF) that is a chronic pulmonary disorder leading to respiratory failure and for which preventive and therapeutic medicines are sorely needed. Matrix metalloproteinases (MMPs), particularly MMP1 and MMP7, have been associated with IPF pathogenesis and are thus relevant to IPF drug discovery. This study evaluates the comparative therapeutic potentials of doxycycline, pirfenidone, and nintedanib in relation to MMP1 and MMP7 using molecular docking, molecular dynamics simulations, and a next-generation phenomics approach. Adsorption, distribution, metabolism, excretion, and toxicity analysis revealed that doxycycline and nintedanib adhered to Lipinski's rule of five, while pirfenidone exhibited no violations. The toxicity analysis revealed favorable safety profiles, with lethal dose 50 values of doxycycline, pirfenidone, and nintedanib being 2240kg, 580, and 500 mg/kg, respectively. Homology modeling validated the accuracy of the structures of the target proteins, that is, MMP1 and MMP7. The Protein Contacts Atlas tool, a next-generation phenomics platform that broadens the scope of phenomics research, was employed to visualize protein contacts at atomic levels, revealing interaction surfaces in MMP1 and MMP7. Docking studies revealed that nintedanib exhibited superior binding affinities with the candidate proteins (-6.9 kcal/mol for MMP1 and -7.9 kcal/mol for MMP7) compared with doxycycline and pirfenidone. Molecular dynamics simulations further demonstrated the stability of protein-ligand complexes. These findings highlight the notable potential of nintedanib in relation to future IPF therapeutics innovation. By integrating in silico and a next-generation phenomics approach, this study opens up new avenues for drug discovery and development for IPF and possibly, for precision/personalized medicines that consider the molecular signatures of therapeutic candidates for each patient.

Metabolite profiling, antimalarial potentials of Schleichera oleosa using LC-MS and GC-MS: in vitro, molecular docking and molecular dynamics

Purpose

To explore the phytochemical composition of Schleichera oleosa bark and evaluate its potential antimalarial activity through in vitro and in silico analyses.

Methods

The bark of S. oleosa was subjected to Soxhlet extraction using petroleum ether, chloroform, and methanol. The quantitative analysis of the extracts was performed to determine total phenolic, flavonoid, and tannin contents. Advanced analytical techniques such as Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS) were employed to identify 175 phytoconstituents from the methanolic extract In-vitro antimalarial activity was assessed against Plasmodium falciparum using the candle jar method, measuring parasite growth inhibition. The inhibitory concentration (IC50) values were calculated and compared with standard antimalarial drugs, chloroquine and quinine. Furthermore, computational analyses, including molecular docking and molecular dynamics simulations, were conducted to evaluate the interactions of identified phytochemicals with key malarial targets (1CEQ and 4ZL4). The efficacy of these compounds was compared with standard drugs like artesunate and chloroquine. Additionally, ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) profiling and drug-likeness assessments were performed.

Results

The methanolic extract of S. oleosa exhibited promising in-vitro antimalarial activity with an average IC50 value of 0.780 μg/mL, which, while higher than chloroquine (0.020 μg/mL) and quinine (0.268 μg/mL), still demonstrated significant efficacy. GC-MS and LC-MS analyses identified 175 phytoconstituents, among which two novel lead compounds, scillarenin and 4-[(Z)-(6-hydroxy-3-oxo-1-benzofuran-2(3H)-ylidene) methyl] phenyl beta-Dglucopyranoside, exhibited the highest docking scores and favorable ADMET profiles. Molecular docking and dynamics simulations confirmed strong binding affinities to malarial targets, surpassing some standard drugs in efficacy.

Conclusion

This study reports, for the first time, the antimalarial potential of bioactive constituents derived from the bark of S. oleosa. The identified compounds, scillarenin and 4-[(Z)-(6-hydroxy-3-oxo-1-benzofuran-2(3H)-ylidene) methyl] phenyl beta-D-glucopyranoside, demonstrated promising antiplasmodial activity, validating traditional medicinal claims. The findings highlight the potential of S. oleosa as a source of novel antimalarial agents with fewer side effects compared to existing therapies. Further in vivo studies are warranted to confirm these results and support the development of new antimalarial drugs. This groundbreaking discovery contributes to the growing evidence supporting the role of medicinal plants in drug discovery.

In silico Characterization of a Hypothetical Protein (PBJ89160.1) from Neisseria meningitidis Exhibits a New Insight on Nutritional Virulence and Molecular Docking to Uncover a Therapeutic Target

Objective

Neisseria meningitidis is an encapsulated, diplococcus, kidney bean-shaped bacteria that causes bacterial meningitis. Our study hopes to advance our understanding of disease progression, the spread frequency of the bacteria in people, and the interactions between the bacteria and human body by identifying a functional protein, potentially serving as a target for meningococcal medicine in the future.

Methods

A hypothetical protein HP (PBJ89160.1) from N. meningitidis was employed in this study for extensive structural and functional characterization. In the predictive functional role of HP, several constitutive bioinformatics approaches are applied, such as prediction of physiological properties, domain and motif family function, secondary and tertiary structure prediction, energy minimization, quality validation, docking, and ADMET analysis. To create the protein's three-dimensional (3D) structure, a template protein (PDB_ID: 3GXA) is used with 99% sequence identity by homology modeling technique with the HHpred server. To mitigate the pathogenicity associated with the HP function, it was docked with the natural ligand methionine and five other drug compounds like Verapamil, Loperamide, Thioridazine, Chlorpromazine, and Auranofine.

Results

The protein is predicted to be acidic, soluble and hydrophilic by physicochemical properties analysis. Subcellular localization analysis demonstrated the protein to be periplasmic. The HP has an ATP-binding cassette transporter (also known as ABC transporter) involved in uptake of methionine (MetQ) that creates nutritional virulence in host. Energy minimization, multiple quality assessments, and validation value determination led to the conclusion that the HP model had a workable and acceptable quality. Following ADMET analysis and binding affinity assessments from the docking studies, Loperamide emerged as the most promising therapeutic compound, effectively inhibiting the ATP transporter activity of the HP.

Conclusion

Comparative genomic analysis revealed that this protein is specific to N. meningitidis and has no homologs in human proteins, thereby identifying it as a potential target for therapeutic intervention.

Molecular Characterization and Potential Inhibitors Prediction of Protein Arginine Methyltransferase-2 in Carcinoma: An Insight from Molecular Docking, ADMET Profiling and Molecular Dynamics Simulation Studies

Objectives

To predict and characterize the three-dimensional (3D) structure of protein arginine methyltransferase 2 (PRMT2) using homology modeling, besides, the identification of potent inhibitors for enhanced comprehension of the biological function of this protein arginine methyltransferase (PRMT) family protein in carcinogenesis.

Materials and methods

An in silico method was employed to predict and characterize the three-dimensional structure. The bulk of PRMTs in the PDB shares just a structurally conserved catalytic core domain. Consequently, it was determined that ligand compounds may be the source of co-crystallized complexes containing additional PRMTs. Possible PRMT2 inhibitor compounds are found by using S-adenosyl methionine (SAM), a methyl group donor, as a positive control.

Results

Protein arginine methyltransferases are associated with a range of physiological processes, including as splicing, proliferation, regulation of the cell cycle, differentiation, and signaling of DNA damage. These functional capacities are also related to carcinogenesis and metastasis-several forms of PRMT have been cited in the literature. These include PRMT-1, PRMT-2, and PRMT-5. Among these, the role of PRMT-2 has been shown in breast cancer and hepatocellular carcinoma. To gain more insights into the role of PRMT2 in cancer pathogenesis, we opted to characterize tertiary structure utilizing an in silico approach. The majority of PRMTs in the PDB have a structurally conserved catalytic core domain. Thus, ligand compounds were identified as a possible source of co-crystallized complexes of other PRMTs. The SAM, a methyl group donor, is used as a positive control in order to identify potential inhibitor compounds of PRMT2 by the virtual screening method. We hypothesized that an inhibitor for other PRMTs could alter PRMT2 activities. Out of 45 inhibitor compounds, we ultimately identified three potential inhibitor compounds based on the results of the pharmacokinetics and binding affinity studies. These compounds are identified as 3BQ (PubChem CID: 77620540), 6DX (PubChem CID: 124222721), and TDU (PubChem CID: 53346504). Their binding affinities are -8.5 kcal/mol, -8.1 kcal/mol, and -8.8 kcal/mol, respectively. These compounds will be further investigated to determine the binding stability and compactness using molecular dynamics simulations on a 100 ns time scale. In vitro and in vivo studies may be conducted with these three compounds, and we think that focusing on them might lead to the creation of a PRMT2 inhibitor.

Conclusion

Three strong inhibitory compounds that were non-carcinogenic also have drug-like properties. By using desirable parameters in root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (Rg), solvent accessible surface area (SASA), molecular surface area (MolSA), and intermolecular hydrogen bonding, complexes verified structural stability and compactness over the 100 ns time frame.

How to cite this article

Hossen MS, Islam MN, Pramanik MEA et al. Molecular Characterization and Potential Inhibitors Prediction of Protein Arginine Methyltransferase-2 (PRMT2) in Carcinoma: An Insight from Molecular Docking, ADMET Profiling and Molecular Dynamics Simulation Studies. Euroasian J Hepato-Gastroenterol 2024;14(2):160-171.

Biochemical, Bioinformatic, and Structural Comparisons of Transketolases and Position of Human Transketolase in the Enzyme Evolution

Transketolases (TKs) are key enzymes of the pentose phosphate pathway, regulating several other critical pathways in cells. Considering their metabolic importance, TKs are expected to be conserved throughout evolution. However, Tittmann et al. (J Biol Chem, 2010, 285(41): 31559-31570) demonstrated that Homo sapiens TK (hsTK) possesses several structural and kinetic differences compared to bacterial TKs. Here, we study 14 TKs from pathogenic bacteria, fungi, and parasites and compare them with hsTK using biochemical, bioinformatic, and structural approaches. For this purpose, six new TK structures are solved by X-ray crystallography, including the TK of Plasmodium falciparum. All of these TKs have the same general fold as bacterial TKs. This comparative study shows that hsTK greatly differs from TKs from pathogens in terms of enzymatic activity, spatial positions of the active site, and monomer-monomer interface residues. An ubiquitous structural pattern is identified in all TKs as a six-residue histidyl crown around the TK cofactor (thiamine pyrophosphate), except for hsTK containing only five residues in the crown. Residue mapping of the monomer-monomer interface and the active site reveals that hsTK contains more unique residues than other TKs. From an evolutionary standpoint, TKs from animals (including H. sapiens) and Schistosoma sp. belong to a distinct structural group from TKs of bacteria, plants, fungi, and parasites, mostly based on a different linker between domains, raising hypotheses regarding evolution and regulation.

Acyl pyrazole sulfonamides as new antidiabetic agents: synthesis, glucosidase inhibition studies, and molecular docking analysis

Diabetes mellitus is a multi-systematic chronic metabolic disorder and life-threatening disease resulting from impaired glucose homeostasis. The inhibition of glucosidase, particularly α-glucosidase, could serve as an effective methodology in treating diabetes. Attributed to the catalytic function of glucosidase, the present research focuses on the synthesis of sulfonamide-based acyl pyrazoles (5a-k) followed by their in vitro and in silico screening against α-glucosidase. The envisaged structures of prepared compounds were confirmed through NMR and FTIR spectroscopy and mass spectrometry. All compounds were found to be more potent against α-glucosidase than the standard drug, acarbose (IC50 = 35.1 ± 0.14 µM), with IC50 values ranging from 1.13 to 28.27 µM. However, compound 5a displayed the highest anti-diabetic activity (IC50 = 1.13 ± 0.06 µM). Furthermore, in silico studies revealed the intermolecular interactions of most potent compounds (5a and 5b), with active site residues reflecting the importance of pyrazole and sulfonamide moieties. This interaction pattern clearly manifests various structure-activity relationships, while the docking results correspond to the IC50 values of tested compounds. Hence, recent investigation reveals the medicinal significance of sulfonamide-clubbed pyrazole derivatives as prospective therapeutic candidates for treating type 2 diabetes mellitus (T2DM).

Synthesis, Glucosidase Inhibition, and In Silico Modeling Analysis of Highly Fluorinated 2-Imino-1,3-thiazolines in Search of Potent Antidiabetic Agents

In the present work, 2-imino-1,3-thiazolines featuring highly fluorinated fragments were synthesized through a straightforward cyclization of diversely substituted thioureas with 2-bromo-1-(4-fluorophenyl)ethan-1-one. The target compounds were obtained in good yields, and structures were established by FTIR and 1H- and 13C NMR spectroscopic methods. The in vitro biological assay revealed that all the compounds significantly obstruct the α-glucosidase. Compound 6d (3-fluoro-N-(3-(2-fluorophenyl)-4-(4-fluorophenyl)thiazol-2(3H)-ylidene)benzamide) showed the highest antidiabetic potential with an IC50 value of 1.47 ± 0.05 μM. In addition, computational analysis revealed the binding energy of -11.1 kcal/mol for 6d which was lower than the positive standard, acarbose (-7.9 kcal/mol). Several intermolecular interactions between the active site residues and 6d highlight the significance of 2-imino-1,3-thiazoline core in attaining the potent efficacy and making these compounds a valuable pharmacophore in drug discovery.

Structural determination and kinetic analysis of the transketolase from Vibrio vulnificus reveal unexpected cooperative behavior

Vibrio vulnificus (vv) is a multidrug-resistant human bacterial pathogen whose prevalence is expected to increase over the years. Transketolases (TK), transferases catalyzing two reactions of the nonoxidative branch of the pentose-phosphate pathway and therefore linked to several crucial metabolic pathways, are potential targets for new drugs against this pathogen. Here, the vvTK is crystallized and its structure is solved at 2.1 Å. A crown of 6 histidyl residues is observed in the active site and expected to participate in the thiamine pyrophosphate (cofactor) activation. Docking of fructose-6-phosphate and ferricyanide used in the activity assay, suggests that both substrates can bind vvTK simultaneously. This is confirmed by steady-state kinetics showing a sequential mechanism, on the contrary to the natural transferase reaction which follows a substituted mechanism. Inhibition by the I38-49 inhibitor (2-(4-ethoxyphenyl)-1-(pyrimidin-2-yl)-1H-pyrrolo[2,3-b]pyridine) reveals for the first time a cooperative behavior of a TK and docking experiments suggest a previously undescribed binding site at the interface between the pyrophosphate and pyridinium domains.

Antimalarial Activity of Anacardium occidentale Leaf Extracts Against Plasmodium falciparum Transketolase (PfTK)

BACKGROUND

As per estimates by WHO in 2021 almost half of the world's population was at risk of malaria and > 0.6 million deaths were attributed to malaria. Therefore, the present study was aimed to explore the antimalarial activity of extracts derived from the leaves of the plant Anacardium occidentale L., which has been used traditionally for the treatment of malaria. Different extracts of A. occidentale leaves were prepared and tested for their inhibitory activity against recombinant P. falciparum transketolase (rPfTK) enzyme, in vitro. Further, growth inhibitory activity against cultivated blood stage P. falciparum parasites (3D7 strain), was studied using SYBR Green fluorescence-based in vitro assays. Acute toxicity of the hydro alcoholic extracts of leaves of A. occidentale (HELA) at different concentrations was evaluated on mice and Zebra fish embryos. HELA showed 75.45 ± 0.35% inhibitory activity against the recombinant PfTk and 99.31 ± 0.08% growth inhibition against intra-erythrocytic stages of P. falciparum at the maximum concentration (50 µg/ml) with IC50 of 4.17 ± 0.22 µg/ml. The toxicity test results showed that the heartbeat, somite formation, tail detachment and hatching of embryos were not affected when Zebra fish embryos were treated with 0.1 to 10 µg/ml of the extract. However, at higher concentrations of the extract, at 48 h (1000 µg/ml) and 96 h (100 µg/ml and 1000 µg/ml, respectively) there was no heartbeat in the fish embryos. In the acute oral toxicity tests performed on mice, the extract showed no toxicity up to 300 mg/kg body weight in mice.

CONCLUSION

The hydro-alcoholic extract of leaves of A. occidentale L. showed potent antimalarial activity against blood stage P. falciparum. Based on the observed inhibitory activity on the transketolase enzyme of P. falciparum it is likely that this enzyme is the target for the development of bioactive molecules present in the plant extracts. The promising anti-malarial activity of purified compounds from leaves of A. occidentale needs to be further explored for development of new anti-malarial therapy.

Deciphering the antimicrobial, antibiofilm and membrane stabilizing synergism of Mikania scandens (L.) Willd. leaves and stems substantiation through in vitro and in silico studies

Considering the traditional application of Mikania scandens (L.) Willd. against wounds and itching. Leaves (MSL) and stems (MSS) were sequentially extracted using solvents petroleum-ether, carbon-tetrachloride, chloroform, ethyl-acetate and ethanol. Disk-diffusion assay revealed the ethyl acetate MSL and MSS extracts were the prominent against ten bacteria, five carbapenem-resistant bacteria and one fungal strains. Subsequent quantitative antimicrobial analysis specified MSL extractives more potent over MSS with lower 1500 and 3500µg/ml MIC and MBC value in both gram-negative and positive bacteria. These sturdiest ethyl-acetate MSL extractives antimicrobial efficiency also fostered fungicidal activity having lower 100µg/ml MFC. Whereat, almost homologous 160-180 min timing noted liken to standard ciprofloxacin susceptibility in both strains, 75% biofilm inhibition at 2×MIC concentration along with 92±0.2% membrane stabilizing activities over synthetic counterparts prospected in preceding standard extractives. Computational molecular docking of MSL compounds supported this findings therefore forego this valuable synergistic insight as antimicrobial agents to efficiently eradicate human infections.

Peonidin-3-O-Glucoside from Purple Corncob Ameliorates Nonalcoholic Fatty Liver Disease by Regulating Mitochondrial and Lysosome Functions to Reduce Oxidative Stress and Inflammation

A frequent chronic liver condition across the world is nonalcoholic fatty liver disease (NAFLD). Oxidative stress caused by lipid accumulation is generally considered to be the main cause of NAFLD. Anthocyanins can effectively inhibit the production of reactive oxygen species and improve oxidative stress. In this work, six major anthocyanins were separated from purple corncob by semi-preparative liquid chromatography. The effects of the 6 kinds of anthocyanins against NAFLD were investigated using a free fatty acid (FFA)-induced cell model. The results showed that peonidin 3-O-glucoside (P3G) can significantly reduce lipid accumulation in the NAFLD cell model. The treatment with P3G also inhibited oxidative stress via inhibiting the excessive production of reactive oxygen species and superoxide anion, increasing glutathione levels, and enhancing the activities of SOD, GPX, and CAT. Further studies unveiled that treatment with P3G not only alleviated inflammation but also improved the depletion of mitochondrial content and damage of the mitochondrial electron transfer chain developed concomitantly in the cell model. P3G upregulated transcription factor EB (TFEB)-mediated lysosomal function and activated the peroxisome proliferator-activated receptor alpha (PPARα)-mediated peroxisomal lipid oxidation by interacting with PPARα possibly. Overall, this study added to our understanding of the protective effects of purple corn anthocyanins against NAFLD and offered suggestions for developing functional foods containing these anthocyanins.

Drug and Anti-Viral Peptide Design to Inhibit the Monkeypox Virus by Restricting A36R Protein

Most recently, monkeypox virus (MPXV) has emanated as a global public health threat. Unavailability of effective medicament against MPXV escalates demand for new therapeutic agent. In this study, in silico strategies were conducted to identify novel drug against the A36R protein of MPXV. The A36R protein of MPXV is responsible for the viral migration, adhesion, and vesicle trafficking to the host cell. To block the A36R protein, 4893 potential antiviral peptides (AVPs) were retrieved from DRAMP and SATPdb databases. Finally, 57 sequences were screened based on peptide filtering criteria, which were then modeled. Likewise, 31 monkeypox virus A36R protein sequences were collected from NCBI protein database to find consensus sequence and to predict 3D protein model. The refined and validated models of the A36R protein and AVP peptides were used to predict receptor-ligand interactions using DINC 2 server. Three peptides that showed best interactions were SATPdb10193, SATPdb21850, and SATPdb26811 with binding energies -6.10, -6.10, and -6.30 kcal/mol, respectively. Small molecules from drug databases were also used to perform virtual screening against the A36R protein. Among databases, Enamine-HTSC showed strong affinity with docking scores ranging from -8.8 to 9.8 kcal/mol. Interaction of target protein A36R with the top 3 peptides and the most probable drug (Z55287118) examined by molecular dynamic (MD) simulation. Trajectory analyses (RMSD, RMSF, SASA, and Rg) confirmed the stable nature of protein-ligand and protein-peptide complexes. This work suggests that identified top AVPs and small molecules might interfere with the function of the A36R protein of MPXV.

Identification of novel inhibitors of high affinity iron permease (FTR1) through implementing pharmacokinetics index to fight against black fungus: An in silico approach

Mucormycosis is a life-threatening fungal infection, particularly in immunocompromised patients. Mucormycosis has been reported to show resistance to available antifungal drugs and was recently found in COVID-19 as a co-morbidity that demands new classes of drugs. In an attempt to find novel inhibitors against the high-affinity iron permease (FTR1), a novel target having fundamental importance on the pathogenesis of mucormycosis, 11,000 natural compounds were investigated in this study. Virtual screening and molecular docking identified two potent natural compounds [6',7,7,10',10',13'-hexamethylspiro[1,8-dihydropyrano[2,3-g]indole-3,11'-3,13-diazatetracyclo[5.5.2.01,9.03,7]tetradecane]-2,9,14'-trione and 5,7-dihydroxy-3-(2,2,8,8-tetramethylpyrano[2,3-f]chromen-6-yl)chromen-4-one] that effectively bind to the active cavity of FTR1 with a binding affinity of -9.9 kcal/mol. Multiple non-covalent interactions between the compounds and the active residues of this cavity were noticed, which is required for FTR1 inhibition. These compounds were found to have inhibitory nature and meet essential requirements to be drug-like compounds with a considerable absorption, distribution, metabolism, and excretion (ADME) profile with no toxicity probabilities. Molecular dynamics simulation confirms the structural compactness and less conformational variation of the drug-protein complexes maintaining structural stability and rigidity. MM-PBSA and post-simulation analysis predict binding stability of these compounds in the active cavity. This study hypothesizing that these compounds could be a potential inhibitor of FTR1 and will broaden the clinical prospects of mucormycosis.

Discovery of Novel PI3Kδ Inhibitors Based on the p110δ Crystal Structure

PI3Kδ is a key mediator of B-cell receptor signaling and plays an important role in the pathogenesis of certain hematological malignancies, such as chronic lymphocytic leukemia. Idelalisib, which targets PI3Kδ specifically, is the first approved PI3K inhibitor for cancer therapy. Recently, we carried out virtual screening, cell-based assays, adapta kinase assays, and molecular dynamic analysis to discover novel PI3Kδ inhibitors and identified NSC348884 as a lead PI3Kδ inhibitor. NSC348884 had an excellent docking score, potent PI3Kδ-inhibitory activity, antitumor effects on various cancer cell lines, and a favorable binding mode with the active site of PI3Kδ. Moreover, through the structural modification of NSC348884, we further discovered comp#1, which forms H-bonds with both Val828 and Lys779 in the ATP binding pocket of PI3Kδ, with a more favorable conformation binding to PI3Kδ. In addition, we found that N¹, N¹, N²-trimethyl-N²-((6-methyl-1H-benzo[d]imidazol-2-yl) methyl) ethane-1,2-diamine might be a potential scaffold structure. Thus, the result of this study provides a far more efficient approach for discovering novel inhibitors targeting PI3Kδ.

Antibacterial, Anticandidal, and Antibiofilm Potential of Fenchone: In Vitro, Molecular Docking and In Silico/ADMET Study

The aim of the present study is to investigate the effective antimicrobial and antibiofilm properties of fenchone, a biologically active bicyclic monoterpene, against infections caused by bacteria and Candida spp. The interactions between fenchone and three distinct proteins from Escherichia coli (β-ketoacyl acyl carrier protein synthase), Candida albicans (1, 3-β−D-glucan synthase), and Pseudomonas aeruginosa (Anthranilate-CoA ligase) were predicted using molecular docking and in silico/ADMET methods. Further, to validate the in-silico prediction, the antibacterial and antifungal potential of fenchone was evaluated against E. coli, P. aeruginosa, and C. albicans by determining minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC), and minimum fungicidal concentration (MFC). The lowest MIC/MBC values of fenchone against E. coli and P. aeruginosa obtained was 8.3 ± 3.6/25 ± 0.0 and 266.6 ± 115.4/533.3 ± 230.9 mg/mL, respectively, whereas the MIC/MFC value for C. albicans was found to be 41.6 ± 14.4/83.3 ± 28.8 mg/mL. It was observed that fenchone has a significant effect on antimicrobial activity (p < 0.05). Our findings demonstrated that fenchone at 1 mg/mL significantly reduced the production of biofilm (p < 0.001) in E. coli, P. aeruginosa, and C. albicans by 70.03, 64.72, and 61.71%, respectively, in a dose-dependent manner when compared to control. Based on these results, it has been suggested that the essential oil from plants can be a great source of pharmaceutical ingredients for developing new antimicrobial drugs.

Virtual screening and molecular dynamic simulations of the antimalarial derivatives of 2-anilino 4-amino substituted quinazolines docked against a Pf-DHODH protein target

Background

The processes of drug development and validation are too expensive to be subjected to experimental trial and errors. Hence, the use of the insilico approach becomes imperative. To this effect, the drug-likeness and pharmacokinetic properties of the ten (10) previously designed derivatives of 2-anilino 4-amino substituted quinazolines were carried out. Their predicted ligand binding interactions were also carried out by docking them against the Plasmodium falciparum dihydroorotate dehydrogenase (Pf-DHODH) protein target, and the stability of the complex was determined through dynamic simulations. The drug-likeness and pharmacokinetic characteristics were estimated using the online SwissADME software, while the Molegro Virtual Docker (MVD) software was used for molecular docking. And the dynamic simulation was performed for the duration of 100 ns to verify the stability of the docked complex, with the aid of a Schrödinger program, Desmond.

Results

The designed derivatives were all found to pass the Lipinski test of drug likeness, while the pharmacokinetic studies result that the skin permeability and molar refractivity values of the derivatives are both within the limits. In addition, except for derivative C-01, most of the derivatives have strong gastrointestinal absorptions and lack Pgp substrate. Furthermore, no derivative inhibited CYP1A2, CYP2C9, or CYP2C19. The docking studies show the better binding affinities between the ligands and Pf-DHODH than those between the atovaquone or chloroquine standards. The derivative C-02, {5-((6,7-dimethoxy-4-((3-nitrobenzyl)amino)quinazolin-2-yl)amino)-2-fluorobenzaldehyde} was found to be the most stable derivative, with a re-rank docking score of - 173.528 kcal/mol and interaction energy of - 225.112 kcal/mol. The dynamic simulation analysis shows that the derivative C-02 forms a stable complex with the protein target over the simulation time.

Conclusions

The ability of these ligands to form hydrogen bonds, as well as various other interactions, was cited as a factor responsible for their better binding affinity. These findings could aid further the development of enhanced antimalarial drugs.

In silico prediction of putative antimicrobial targets in Xanthomonas citri pv. punicae using genome subtraction approach

Xanthomonas citri pv. punicae (Xcp) is the causative agent of bacterial blight disease in pomegranate and severely affects its production. The current control strategies for this disease provide inadequate protection. Identifying novel bactericide target proteins in pathogenic bacteria and formulating selective chemicals against those proteins is an effective approach to containing the disease. In this study, we used the genome subtraction approach and identified 595 Xcp proteins that are non-homologous to the pomegranate proteome, of which 69 are found to be essential proteins. These 69 proteins are considered possible drug target proteins in Xcp. Further, these proteins were subjected to subcellular localization, KEGG pathway, and virulent prediction analysis. Our systematic bioinformatics analysis deciphered 33 virulent proteins, of which two are iron complex outer membrane receptors, and the third is a T4SS PilQ protein localized in the outer membrane. These outer membrane-localized proteins are potential candidate targets for antibacterial agents, and the two iron complex outer membrane receptor proteins show homology with the Drug bank listed drug target sequences. From this study, we inferred that PilQ could be considered a novel antimicrobial target of Xcp, and therefore we deciphered the PilQ protein-protein interacting partners and phylogenetic relatedness. We have also predicted the physiochemical properties, secondary, and tertiary structure of PilQ protein which will be helpful in the design of antimicrobials. The identification of Xcp specific targets is the first step towards the development of a chemical control agent that is more selective with minimum environmental impact.

Hypothetical protein predicted to be tumor suppressor: a protein functional analysis

Litorilituus sediminis is a Gram-negative, aerobic, novel bacterium under the family of Colwelliaceae, has a stunning hypothetical protein containing domain called von Hippel-Lindau that has significant tumor suppressor activity. Therefore, this study was designed to elucidate the structure and function of the biologically important hypothetical protein EMK97_00595 (QBG34344.1) using several bioinformatics tools. The functional annotation exposed that the hypothetical protein is an extracellular secretory soluble signal peptide and contains the von Hippel-Lindau (VHL; VHL beta) domain that has a significant role in tumor suppression. This domain is conserved throughout evolution, as its homologs are available in various types of the organism like mammals, insects, and nematode. The gene product of VHL has a critical regulatory activity in the ubiquitous oxygen-sensing pathway. This domain has a significant role in inhibiting cell proliferation, angiogenesis progression, kidney cancer, breast cancer, and colon cancer. At last, the current study depicts that the annotated hypothetical protein is linked with tumor suppressor activity which might be of great interest to future research in the higher organism.

Biochemical and Molecular Dynamics Study of a Novel GH 43 α-l-Arabinofuranosidase/β-Xylosidase From Caldicellulosiruptor saccharolyticus DSM8903

The complete hydrolysis of xylan can be facilitated by the coordinated action of xylanase and other de-branching enzymes. Here, a GH43 α-l-arabinofuranosidase/β-xylosidase (CAX43) from Caldicellulosiruptor saccharolyticus was cloned, sequenced, and biochemically investigated. The interaction of the enzyme with various substrates was also studied. With a half-life of 120 h at 70°C, the produced protein performed maximum activity at pH 6.0 and 70°C. The enzyme demonstrated a higher activity (271.062 ± 4.83 U/mg) against para nitrophenol (pNP) α-L-arabinofuranosides. With xylanase (XynA), the enzyme had a higher degree of synergy (2.30) in a molar ratio of 10:10 (nM). The interaction of the enzyme with three substrates, pNP α-L-arabinofuranosides, pNP β-D-xylopyranosides, and sugar beet arabinan, was investigated using protein modeling, molecular docking, and molecular dynamics (MD) simulation. During the simulation time, the root mean square deviation (RMSD) of the enzyme was below 2.5 Å, demonstrating structural stability. Six, five, and seven binding-interacting residues were confirmed against pNP α-L-arabinofuranosides, pNP β-D-xylopyranosides, and arabinan, respectively, in molecular docking experiments. This biochemical and in silico study gives a new window for understanding the GH43 family’s structural stability and substrate recognition, potentially leading to biological insights and rational enzyme engineering for a new generation of enzymes that perform better and have greater biorefinery utilization.

Comparative molecular investigation of the potential inhibitors against SARS-CoV-2 main protease: a molecular docking study

Recent outbreak of novel coronavirus and its rapid pandemic escalation in all over the world has drawn the attention to urgent need for effective drug development. However, due to prolonged vaccine and drug development procedure against a newly emerged devastating SARS-CoV-2 virus pathogen, repurposing of existing potential pertinent drug molecules would be preferable strategy to reduce mortality immediately and further development of new drugs to combat overall global Covid-19 crisis in all over the world. Herein, we have filtered 23 prospective drug candidates through literature review. Assessing evidences from molecular docking studies, it was clearly seen that, Epirubicin, Vapreotida, and Saquinavir exhibited better binding affinity against SARS-CoV-2 Main Protease than other drug molecules among the 23 potential inhibitors. However, 50 ns molecular dynamics simulation indicated the less mobile nature of the docked complex maintaining structural integrity. Our overall prediction findings indicate that Epirubicin, Vapreotida, and Saquinavir may inhibit COVID-19 by synergistic interactions in the active cavity and those results can pave the way in drug discovery although it has to be further validated by in-vitro and in-vivo investigations.Communicated by Ramaswamy H. Sarma.

In silico characterization and structural modeling of bacterial metalloprotease of family M4

BACKGROUND

The M4 family of metalloproteases is comprised of a large number of zinc-containing metalloproteases. A large number of these enzymes are important virulence factors of pathogenic bacteria and therefore potential drug targets. Whereas some enzymes have potential for biotechnological applications, the M4 family of metalloproteases is known almost exclusively from bacteria. The aim of the study was to identify the structure and properties of M4 metalloprotease proteins.

RESULTS

A total of 31 protein sequences of M4 metalloprotease retrieved from UniProt representing different species of bacteria have been characterized for various physiochemical properties. They were thermostable, hydrophillic protein of a molecular mass ranging from 38 to 66 KDa. Correlation on the basis of both enzymes and respective genes has also been studied by phylogenetic tree. B. cereus M4 metalloprotease (PDB ID: 1NPC) was selected as a representative species for secondary and tertiary structures among the M4 metalloprotease proteins. The secondary structure displaying 11 helices (H1-H11) is involved in 15 helix-helix interactions, while 4 β-sheet motifs composed of 15 β-strands in PDBsum. Possible disulfide bridges were absent in most of the cases. The tertiary structure of B. cereus M4 metalloprotease was validated by QMEAN4 and SAVES server (Ramachandran plot, verify 3D, and ERRAT) which proved the stability, reliability, and consistency of the tertiary structure of the protein. Functional analysis was done in terms of membrane protein topology, disease-causing region prediction, proteolytic cleavage sites prediction, and network generation. Transmembrane helix prediction showed absence of transmembrane helix in protein. Protein-protein interaction networks demonstrated that bacillolysin of B. cereus interacted with ten other proteins in a high confidence score. Five disorder regions were identified. Active sites analysis showed the zinc-binding residues-His-143, His-147, and Glu-167, with Glu-144 acting as the catalytic residues.

CONCLUSION

Moreover, this theoretical overview will help researchers to get a details idea about the protein structure and it may also help to design enzymes with desirable characteristics for exploiting them at industrial level or potential drug targets.

Plasmodium yoelii Uses a TLR3-Dependent Pathway to Achieve Mammalian Host Parasitism

Malaria is associated with complicated immunopathogenesis. In this study, we provide evidence for an unexpected role of TLR3 in promoting the establishment of Plasmodium yoelii infection through delayed clearance of parasitemia in wild type C57BL/6jRj (B6) compared with TLR3 knockout mice. In this study, we confirmed an increased expression of Tlr3, Trif, Tbk1, and Irf7/Irf3 in the liver 42 h postinfection and the initiation of an early burst of proinflammatory response such as Ifng, NF-kB, and Tnfa in B6 mice that may promote parasite fitness. Interestingly, in the absence of TLR3, we showed the involvement of high IFN-γ and lower type I IFN response in the early clearance of parasitemia. In parallel, we observed an increase in splenic NK and NKT cells expressing TLR3 in infected B6 mice, suggesting a role for TLR sensing in the innate immune response. Finally, we find evidence that the increase in the frequency of CD19⁺TLR3⁺ B cells along with reduced levels of total IgG in B6 mice possibly suggests the initiation of TLR3-dependent pathway early during P. yoelii infection. Our results thus reveal a new mechanism in which a parasite-activated TLR3 pathway promotes blood stage infection along with quantitative and qualitative differences in Ab responses.

Characterisation of plasmodial transketolases and identification of potential inhibitors: an in silico study

BACKGROUND

Plasmodial transketolase (PTKT) enzyme is one of the novel pharmacological targets being explored as potential anti-malarial drug target due to its functional role and low sequence identity to the human enzyme. Despite this, features contributing to such have not been exploited for anti-malarial drug design. Additionally, there are no anti-malarial drugs targeting PTKTs whereas the broad activity of these inhibitors against PTKTs from other Plasmodium spp. is yet to be reported. This study characterises different PTKTs [Plasmodium falciparum (PfTKT), Plasmodium vivax (PvTKT), Plasmodium ovale (PoTKT), Plasmodium malariae (PmTKT) and Plasmodium knowlesi (PkTKT) and the human homolog (HsTKT)] to identify key sequence and structural based differences as well as the identification of selective potential inhibitors against PTKTs.

METHODS

A sequence-based study was carried out using multiple sequence alignment, phylogenetic tree calculations and motif discovery analysis. Additionally, TKT models of PfTKT, PmTKT, PoTKT, PmTKT and PkTKT were modelled using the Saccharomyces cerevisiae TKT structure as template. Based on the modelled structures, molecular docking using 623 South African natural compounds was done. The stability, conformational changes and detailed interactions of selected compounds were accessed viz all-atom molecular dynamics (MD) simulations and binding free energy (BFE) calculations.

RESULTS

Sequence alignment, evolutionary and motif analyses revealed key differences between plasmodial and the human TKTs. High quality homodimeric three-dimensional PTKTs structures were constructed. Molecular docking results identified three compounds (SANC00107, SANC00411 and SANC00620) which selectively bind in the active site of all PTKTs with the lowest (better) binding affinity ≤ - 8.5 kcal/mol. MD simulations of ligand-bound systems showed stable fluctuations upon ligand binding. In all systems, ligands bind stably throughout the simulation and form crucial interactions with key active site residues. Simulations of selected compounds in complex with human TKT showed that ligands exited their binding sites at different time steps. BFE of protein-ligand complexes showed key residues involved in binding.

CONCLUSIONS

This study highlights significant differences between plasmodial and human TKTs and may provide valuable information for the development of novel anti-malarial inhibitors. Identified compounds may provide a starting point in the rational design of PTKT inhibitors and analogues based on these scaffolds.

Molecular Docking in Formulation and Development

BACKGROUND

In pharmaceutical research drug discovery and development process is timeconsuming and expensive. In many cases, it produces incompetent results due to the failure of in vitro and in vivo conventional approaches. Before any new drug is placed in the market it must undergo rigorous testing to get FDA approval. Due to the several limitations imposed by the drug discovery process, in recent times in silico approaches are widely applied in this field. The purpose of this review is to highlight the current molecular docking strategies used in drug discovery and to explore various advances in the field.

METHODS

In this review we have compiled database after an extensive literature search on docking studies which has found its applications relevant to the field of formulation and development. The papers retrieved were further screened to appraise the quality of work. In depth strategic analysis was carried out to confirm the credibility of the findings.

RESULTS

The papers included in this review highlight the promising role of docking studies to overcome the challenges in formulation and development by emphasizing it's applications to predict drug excipient interactions which in turn assist to increase protein stability; to determine enzyme peptide interactions which maybe further used in drug development studies; to determine the most stable drug inclusion complex; to analyze structure at molecular level that ascertain an increase in solubility, dissolution and in turn the bioavailability of the drug; to design a dosage form that amplify the drug discovery and development process.

CONCLUSION

This review summarizes recent findings of critical role played by molecular docking in the process of drug discovery and development. The application of docking approach will assist to design a dosage form in the most cost effective and time saving manner.

Identification of Phosphoinositide-3 Kinases Delta and Gamma Dual Inhibitors Based on the p110δ/γ Crystal Structure

Background:

Phosphoinositide-3 kinases (PI3Ks) are key signaling molecules that affect a diverse array of biological processes in cells, including proliferation, differentiation, survival, and metabolism. The abnormal activity of PI3K signals is closely related to the occurrence of many diseases, which has become a very promising drug target, especially for the treatment of cancer. PI3Kδ/γ inhibitors can reduce toxicity concerns for chronic indications such as asthma and rheumatoid arthritis compared with pan PI3Ks inhibitors.

Methods:

With the aim of finding more effective PI3Kδ/γ dual inhibitors, virtual screening, ADMET prediction Molecular Dynamics (MD) simulations and MM-GBSA were executed based on the known p110δ/γ crystal structure. Compound ZINC28564067 with high docking score and low toxicity was obtained.

Results:

By MD simulations and MM-GBSA, we could observe that ZINC28564067 had more favorable conformation binding to the PI3Kδ/γ than the original ligands.

Conclusion:

The results provided a rapid approach for the discovery of novel PI3Kδ/γ dual inhibitors which might be a potential anti-tumor lead compound.

Structure to function analysis with antigenic characterization of a hypothetical protein,HPAG1_0576 from Helicobacter pylori HPAG1

Helicobacter pylori, a unique gastric pathogen causing chronic inflammation in the gastric mucosa with a possibility to develop gastric cancer has one-third of its proteins still uncharacterized. In this study, a hypothetical protein (HP) namely HPAG1_0576 from H. pylori HPAG1 was chosen for detailed computational analysis of its structural, functional and epitopic properties. The primary, secondary and 3D structure/model of the selected HP was constructed. Then refinement and structure validation were done, which indicated a good quality of the newly constructed model. ProFunc and STRING suggested that HPAG1_0576 shares 98% identity with a carcinogenic factor, TNF-α inducing protein (Tip-α ) of H. pylori. IEDB immunoinformatics tool predicted VLMLQACTCPNTSQRNS from position 19-35 as most potential B-cell linear epitope and SFLKSKQL from position 5-12 as most potent conformational epitope. Alternatively, FALVRARGF and FLCGLGVLM were predicted as most immunogenic CD8+ and CD4+ T-cell epitopes respectively. At the same time findings of IFN epitope tool suggests that, HPAG1_0576 had a great potential to evoke interferon-gamma (IFN-γ) mediated immune response. However, this experiment is a primary approach for in silico vaccine designing from a HP, findings of this study will provide significant insights in further investigations and will assist in identifying new drug targets/vaccine candidates.

A Systematic Review on Popularity, Application and Characteristics of Protein Secondary Structure Prediction Tools

BACKGROUND

Prediction of proteins' secondary structure is one of the major steps in the generation of homology models. These models provide structural information which is used to design suitable ligands for potential medicinal targets. However, selecting a proper tool between multiple Secondary Structure Prediction (SSP) options is challenging. The current study is an insight into currently favored methods and tools, within various contexts.

OBJECTIVE

A systematic review was performed for a comprehensive access to recent (2013-2016) studies which used or recommended protein SSP tools.

METHODS

Three databases, Web of Science, PubMed and Scopus were systematically searched and 99 out of the 209 studies were finally found eligible to extract data.

RESULTS

Four categories of applications for 59 retrieved SSP tools were: (I) prediction of structural features of a given sequence, (II) evaluation of a method, (III) providing input for a new SSP method and (IV) integrating an SSP tool as a component for a program. PSIPRED was found to be the most popular tool in all four categories. JPred and tools utilizing PHD (Profile network from HeiDelberg) method occupied second and third places of popularity in categories I and II. JPred was only found in the two first categories, while PHD was present in three fields.

CONCLUSION

This study provides a comprehensive insight into the recent usage of SSP tools which could be helpful for selecting a proper tool.

Studies on the lipid-regulating mechanism of alisol-based compounds on lipoprotein lipase

Studies on the lipid-regulating effects of alisol compounds are reported that include alisol B, alisol A 24-acetate (24A), alisol A and an alisol B - 24A - alisol A mixture (content ratio = 1:1:1). The effects on the activity of lipoprotein lipase (LPL), a key lipid-modulating enzyme, were studied to investigate the molecular mechanism of lipid-regulating activity of alisols. The effects of alisols on regulating blood lipids and the activities of LPL were determined using a reagent kit method. The structure of LPL was obtained by homology modeling and the interactive mechanism of alisol monomers and the mixture with LPL was investigated by molecular simulation. The alisol monomer and mixture were shown to regulate blood lipids, suggesting that alisols may decrease the level of triglyceride (TG) by improving the activity of LPL. The order of intensity was: mixture > alisol A > alisol B > 24A, indicating that alisols of alismatis rhizoma feature a synergistic effect on LPL. The N- and C-terminus of LPL both represented the catalytic active domains of this lipid-regulating effect. Cys306, Gln129 and Ser166 were the key amino acid residues resulting in the lipid-regulating effect of the alisol monomer while Ser166 and Arg18 were found to be responsible for the lipid-regulating effect of the mixture. The C-terminus of LPL was indirectly involved in the enzymatic process. A folded side chain of alisols or the parent ring was found to bind somewhat weaker to LPL than an open side chain or parent ring. The hydroxyl groups on the C14-, C22-, C28-, C30- and C31-terminus in the side chain, the ring ether structure in C23-position, and the acetyl group in C29-position represented the key sites for the lipid-regulating action of alisols. Meanwhile, the C30-site hydroxyl group played an important role in the synergistic effect of the alisol mixture.

Structural dynamics of Casein Kinase I (CKI) from malarial parasite Plasmodium falciparum (Isolate 3D7): Insights from theoretical modelling and molecular simulations

The protein kinases (PKs), belonging to serine/threonine kinase (STKs), are important drug targets for a wide spectrum of diseases in human. Among protein kinases, the Casein Kinases (CKs) are vastly expanded in various organisms, where, the malarial parasite Plasmodium falciparum possesses a single member i.e., PfCKI, which can phosphorylate various proteins in parasite extracts in vitro condition. But, the structure-function relationship of PfCKI and dynamics of ATP binding is yet to be understood. Henceforth, an attempt was made to study the dynamics, stability, and ATP binding mechanisms of PfCKI through computational modelling, docking, molecular dynamics (MD) simulations, and MM/PBSA binding free energy estimation. Bi-lobed catalytic domain of PfCKI shares a high degree of secondary structure topology with CKI domains of rice, human, and mouse indicating co-evolution of these kinases. Molecular docking study revealed that ATP binds to the active site where the glycine-rich ATP-binding motif (G16-X-G18-X-X-G21) along with few conserved residues plays a crucial role maintaining stability of the complex. Structural superposition of PfCKI with close structural homologs depicted that the location and length of important loops are different, indicating the dynamic properties of these loops among CKIs, which is consistent with principal component analysis (PCA). PCA displayed that the overall global motion of ATP-bound form is comparatively higher than that of apo form. The present study provides insights into the structural features of PfCKI, which could contribute towards further understanding of related protein structures, dynamics of catalysis and phosphorylation mechanism in these important STKs from malarial parasite in near future.

Prediction of deleterious single nucleotide polymorphisms and their effect on the sequence and structure of the human CCND1 gene

Objective

The CCND1 gene expresses a protein, G1/S-specific cyclin, that regulates the G1/S transition in the cell cycle and also inhibits retinoblastoma (RB) proteins. Overexpression or rearrangements of this gene can result in various tumours. This study aimed to identify possible deleterious non-synonymous single nucleotide polymorphisms (SNP's) of CCND1 using computational methods.

Methods

SNPs in the human CCND1 gene were retrieved from dbSNP. These SNPs were screened by the Sorting Intolerant From Tolerant (SIFT) algorithm and the PredictSNP classification. Mutants with deleterious SNPs were built using Discovery Studio 3.5, and dynamics studies were performed on native and mutant varieties.

Results

In Homo sapiens, 1194 SNPs were found, of which 94 were missense and 2 were nonsense SNPs. Three SNPs were found to be deleterious. Molecular dynamics and trajectory analysis showed that there was a significant deviation of the root mean square deviation (RMSD) values in the N216K mutant from the values of the native protein.

Conclusion

Based on this study, we propose that the SNP with SNP ID rs112525097 (NM_053056.2:c.648C>G) might cause aberrations in CCND1, which might lead to a change in the function of the G1/S-specific cyclin protein. This, in turn, may lead to the development of acute myeloid leukaemia (AML).

Molecular docking as a popular tool in drug design, an in silico travel

New molecular modeling approaches, driven by rapidly improving computational platforms, have allowed many success stories for the use of computer-assisted drug design in the discovery of new mechanism-or structure-based drugs. In this overview, we highlight three aspects of the use of molecular docking. First, we discuss the combination of molecular and quantum mechanics to investigate an unusual enzymatic mechanism of a flavoprotein. Second, we present recent advances in anti-infectious agents' synthesis driven by structural insights. At the end, we focus on larger biological complexes made by protein-protein interactions and discuss their relevance in drug design. This review provides information on how these large systems, even in the presence of the solvent, can be investigated with the outlook of drug discovery.