scholarly journals Inhibition of Porcine Aminopeptidase M (pAMP) by the Pentapeptide Microginins

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4369 ◽  
Author(s):  
Glaucio Monteiro Ferreira ◽  
Thales Kronenberger ◽  
Éryka Costa de Almeida ◽  
Joseane Sampaio ◽  
Clélia Ferreira Terra ◽  
...  
Keyword(s):  
Microcystis Aeruginosa ◽  
Molecular Modelling ◽  
Binding Mode ◽  
Methyl Group ◽  
Aminopeptidase M ◽  
Potential Binding ◽  
Ic50 Values ◽  
Cancer Types ◽  
Amp Inhibition

Aminopeptidase M (AMP) inhibition is of interest for several diseases, such as highly vascularized cancer types. AMP can be inhibited by linear pentapeptides isolated from Microcystis aeruginosa LTPNA08 (MG7XX). Porcine AMP inhibition—a model for human AMP—activity was spectrophotometrically measured by the formation of p-nitroanilide from L-leucine-p-nitroanilide substrate by AMP. AMP inhibition by MG770 exhibited comparable inhibition levels to amastatin (IC50 values: 1.20 ± 0.1 μM and 0.98 ± 0.1 μM, respectively), while MG756 was slightly less potent (with IC50 values of 3.26 ± 0.5 μM). Molecular modelling suggests a potential binding mode, based on the interaction with the Zn2+ cofactor, where MG770′s extra methyl group contributes to the disturbance of the Zn2+ cofactor complex and highlights the importance of hydrophobicity for the site.

scholarly journals The Repurposed Drugs Suramin and Quinacrine Cooperatively Inhibit SARS-CoV-2 3CLpro In Vitro

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 873
Author(s):  
Raphael J. Eberle ◽  
Danilo S. Olivier ◽  
Marcos S. Amaral ◽  
Ian Gering ◽  
Dieter Willbold ◽  
...  
Keyword(s):  
Binding Mode ◽  
Drug Candidates ◽  
Main Protease ◽  
Ic50 Values ◽  
Repurposed Drugs ◽  
Antiparasitic Drugs ◽  
Inhibitory Potential ◽  
Dynamics Simulations ◽  
Micromolar Range

Since the first report of a new pneumonia disease in December 2019 (Wuhan, China) the WHO reported more than 148 million confirmed cases and 3.1 million losses globally up to now. The causative agent of COVID-19 (SARS-CoV-2) has spread worldwide, resulting in a pandemic of unprecedented magnitude. To date, several clinically safe and efficient vaccines (e.g., Pfizer-BioNTech, Moderna, Johnson & Johnson, and AstraZeneca COVID-19 vaccines) as well as drugs for emergency use have been approved. However, increasing numbers of SARS-Cov-2 variants make it imminent to identify an alternative way to treat SARS-CoV-2 infections. A well-known strategy to identify molecules with inhibitory potential against SARS-CoV-2 proteins is repurposing clinically developed drugs, e.g., antiparasitic drugs. The results described in this study demonstrated the inhibitory potential of quinacrine and suramin against SARS-CoV-2 main protease (3CLpro). Quinacrine and suramin molecules presented a competitive and noncompetitive inhibition mode, respectively, with IC50 values in the low micromolar range. Surface plasmon resonance (SPR) experiments demonstrated that quinacrine and suramin alone possessed a moderate or weak affinity with SARS-CoV-2 3CLpro but suramin binding increased quinacrine interaction by around a factor of eight. Using docking and molecular dynamics simulations, we identified a possible binding mode and the amino acids involved in these interactions. Our results suggested that suramin, in combination with quinacrine, showed promising synergistic efficacy to inhibit SARS-CoV-2 3CLpro. We suppose that the identification of effective, synergistic drug combinations could lead to the design of better treatments for the COVID-19 disease and repurposable drug candidates offer fast therapeutic breakthroughs, mainly in a pandemic moment.

Design, Synthesis and Docking Studies of Thioimidazolyl Diketoacid Derivatives Targeting HIV-1 Integrase

2021 ◽  
Vol 17 ◽  
Author(s):  
Nafiseh Karimi ◽  
Rouhollah Vahabpour Roudsari ◽  
Zahra Hajimahdi ◽  
Afshin Zarghi
Keyword(s):  
Drug Target ◽  
Enzyme Assay ◽  
Binding Mode ◽  
Docking Studies ◽  
Integrase Inhibitors ◽  
Design Synthesis ◽  
Ic50 Values ◽  
Novel Structures ◽  
Anti Hiv ◽  
Hiv 1

Background: Integrase enzyme is a validated drug target to discover novel structures as anti-HIV-1 agents. Objective: Novel series of thioimidazolyl diketo acid derivatives characterizing various substituents at N-1 and 2-thio positions of central ring were developed as HIV-1 integrase inhibitors. Results: The obtained molecules were evaluated in the enzyme assay, displaying promising integrase inhibitory activity with IC50 values ranging from 0.9 to 7.7 M. The synthesized compounds were also tested for antiviral activity and cytotoxicity using HeLa cells infected by the single-cycle replicable HIV-1 NL4-3. Conclusion: The most potent compound was 18i with EC50=19 µM, IC50 0.9 µM and SI= 10.5. Docking studies indicated that the binding mode of the active molecule is well aligned with the known HIV-1 integrase inhibitors.

scholarly journals Structural and functional studies of pyruvate carboxylase regulation by cyclic di-AMP in lactic acid bacteria

2017 ◽  
Vol 114 (35) ◽  
pp. E7226-E7235 ◽  
Author(s):  
Philip H. Choi ◽  
Thu Minh Ngoc Vu ◽  
Huong Thi Pham ◽  
Joshua J. Woodward ◽  
Mark S. Turner ◽  
...  
Keyword(s):  
Binding Site ◽  
Conformational Changes ◽  
Pyruvate Carboxylase ◽  
Adenosine Monophosphate ◽  
Binding Mode ◽  
Functional Studies ◽  
Cellular Processes ◽  
Wide Range ◽  
A Site ◽  
Amp Inhibition

Cyclic di-3′,5′-adenosine monophosphate (c-di-AMP) is a broadly conserved bacterial second messenger that has been implicated in a wide range of cellular processes. Our earlier studies showed that c-di-AMP regulates central metabolism inListeria monocytogenesby inhibiting its pyruvate carboxylase (LmPC), a biotin-dependent enzyme with biotin carboxylase (BC) and carboxyltransferase (CT) activities. We report here structural, biochemical, and functional studies on the inhibition ofLactococcus lactisPC (LlPC) by c-di-AMP. The compound is bound at the dimer interface of the CT domain, at a site equivalent to that in LmPC, although it has a distinct binding mode in the LlPC complex. This binding site is not well conserved among PCs, and only a subset of these bacterial enzymes are sensitive to c-di-AMP. Conformational changes in the CT dimer induced by c-di-AMP binding may be the molecular mechanism for its inhibitory activity. Mutations of residues in the binding site can abolish c-di-AMP inhibition. InL. lactis, LlPC is required for efficient milk acidification through its essential role in aspartate biosynthesis. The aspartate pool inL. lactisis negatively regulated by c-di-AMP, and high aspartate levels can be restored by expression of a c-di-AMP–insensitive LlPC. LlPC has high intrinsic catalytic activity and is not sensitive to acetyl-CoA activation, in contrast to other PC enzymes.

scholarly journals MicroRNAs: Crucial Regulators of Stress

MicroRNA ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Rabih Roufayel ◽  
Seifedine kadry
Keyword(s):  
Rna Polymerase Ii ◽  
Lymphoproliferative Disease ◽  
Lymphocytic Leukemia ◽  
Lung Tumorigenesis ◽  
Protein Coding ◽  
Mrna Targets ◽  
B Cell Malignancy ◽  
Potential Binding ◽  
Wide Range ◽  
Cancer Types

Background: Signaling pathways including gene silencing, cellular differentiation, homeostasis, development and apoptosis are regulated and controlled by a wide range of miRNAs. Objective: Due to their potential binding sites in human-protein coding genes, many studies have also linked their altered expressions in various cancer types making them tumor suppressors agents. Methods: Moreover, each miRNA is predicted to have many mRNA targets indicating their extensive regulatory role in cell survival and developmental processes. Nowadays, diagnosis of early cancer stage development is now dependent on variable miRNA expression levels as potential oncogenic biomarkers in validating and targeting microRNAs for cancer therapy. Results: As the majority of miRNA, transcripts are derived from RNA polymerase II-directed transcription, stress response could result on a general reduction in the abundance of these transcripts. Over expression of various microRNAs have lead to B cell malignancy, potentiated KrasG12Dinduced lung tumorigenesis, chronic lymphocytic leukemia, lymphoproliferative disease and autoimmunity. Conclusion: Altered miRNA expressions could have a significant impact on the abundance of proteins, making them attractive candidates as biomarkers for cancer detection and important regulators of apoptosis.

scholarly journals Design, Synthesis, and Biological Evaluation of Pyridineamide Derivatives Containing a 1,2,3-Triazole Fragment as Type II c-Met Inhibitors

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 10 ◽  
Author(s):  
Hehua Xiong ◽  
Jianxin Cheng ◽  
Jianqing Zhang ◽  
Qian Zhang ◽  
Zhen Xiao ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Cell Lines ◽  
Inhibitory Activity ◽  
Docking Simulation ◽  
Binding Mode ◽  
Biological Evaluation ◽  
Design Synthesis ◽  
Ic50 Values ◽  
Mcf 7

A series of 4-(pyridin-4-yloxy)benzamide derivatives containing a 1,2,3-triazole fragment were designed, synthesized, and their inhibitory activity against A549, HeLa, and MCF-7 cancer cell lines was evaluated. Most compounds exhibited moderate to potent antitumor activity against the three cell lines. Among them, the promising compound B26 showed stronger inhibitory activity than Golvatinib, with IC50 values of 3.22, 4.33, and 5.82 μM against A549, HeLa, and MCF-7 cell lines, respectively. The structure–activity relationships (SARs) demonstrated that the modification of the terminal benzene ring with a single electron-withdrawing substituent (fluorine atom) and the introduction of a pyridine amide chain with a strong hydrophilic group (morpholine) to the hinge region greatly improved the antitumor activity. Meanwhile, the optimal compound B26 showed potent biological activity in some pharmacological experiments in vitro, such as cell morphology study, dose-dependent test, kinase activity assay, and cell cycle experiment. Finally, the molecular docking simulation was performed to further explore the binding mode of compound B26 with c-Met.

scholarly journals Molecular Basis for Endocrine Disruption by Pesticides Targeting Aromatase and Estrogen Receptor

2020 ◽  
Vol 17 (16) ◽  
pp. 5664 ◽  
Author(s):  
Chao Zhang ◽  
Tiziana Schilirò ◽  
Marta Gea ◽  
Silvia Bianchi ◽  
Angelo Spinello ◽  
...  
Keyword(s):  
Competitive Inhibition ◽  
Estrogenic Activity ◽  
Endocrine Disrupting Chemicals ◽  
Binding Mode ◽  
Inhibition Mechanism ◽  
Aromatase Activity ◽  
Docking Simulations ◽  
Potential Binding ◽  
Endocrine Disrupting ◽  
17Β Estradiol

The intensive use of pesticides has led to their increasing presence in water, soil, and agricultural products. Mounting evidence indicates that some pesticides may be endocrine disrupting chemicals (EDCs), being therefore harmful for the human health and the environment. In this study, three pesticides, glyphosate, thiacloprid, and imidacloprid, were tested for their ability to interfere with estrogen biosynthesis and/or signaling, to evaluate their potential action as EDCs. Among the tested compounds, only glyphosate inhibited aromatase activity (up to 30%) via a non-competitive inhibition or a mixed inhibition mechanism depending on the concentration applied. Then, the ability of the three pesticides to induce an estrogenic activity was tested in MELN cells. When compared to 17β-estradiol, thiacloprid and imidacloprid induced an estrogenic activity at the highest concentrations tested with a relative potency of 5.4 × 10−10 and 3.7 × 10−9, respectively. Molecular dynamics and docking simulations predicted the potential binding sites and the binding mode of the three pesticides on the structure of the two key targets, providing a rational for their mechanism as EDCs. The results demonstrate that the three pesticides are potential EDCs as glyphosate acts as an aromatase inhibitor, whereas imidacloprid and thiacloprid can interfere with estrogen induced signaling.

scholarly journals Tris-(2-pyridyl)-pyrazolyl Borate Zinc(II) Complexes: Synthesis, DNA/Protein Binding and In Vitro Cytotoxicity Studies

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7341
Author(s):  
Manmath Narwane ◽  
Dorothy Priyanka Dorairaj ◽  
Yu-Lun Chang ◽  
Ramasamy Karvembu ◽  
Yu-Han Huang ◽  
...  
Keyword(s):  
Anticancer Agents ◽  
Binding Mode ◽  
In Vitro Cytotoxicity ◽  
Visible Absorption ◽  
Cytotoxicity Studies ◽  
Ic50 Values ◽  
State Behaviour ◽  
Analytical Tools ◽  
Ct Dna

Zn(II) complexes bearing tris[3-(2-pyridyl)-pyrazolyl] borate (Tppy) ligand (1–3) was synthesized and examined by spectroscopic and analytical tools. Mononuclear [TppyZnCl] (1) has a Zn(II) centre with one arm (pyrazolyl-pyridyl) dangling outside the coordination sphere which is a novel finding in TppyZn(II) chemistry. In complex [TppyZn(H2O)][BF4] (2) hydrogen bonding interaction of aqua moiety stabilizes the dangling arm. In addition, solution state behaviour of complex 1 confirms the tridentate binding mode and reactivity studies show the exogenous axial substituents used to form the [TppyZnN3] (3). The complexes (1–3) were tested for their ability to bind with Calf thymus (CT) DNA and Bovine serum albumin (BSA) wherein they revealed to exhibit good binding constant values with both the biomolecules in the order of 104–105 M−1. The intercalative binding mode with CT DNA was confirmed from the UV-Visible absorption, viscosity, and ethidium bromide (EB) DNA displacement studies. Further, the complexes were tested for in vitro cytotoxic ability on four triple-negative breast cancer (TNBC) cell lines (MDA-MB-231, MDA-MB-468, HCC1937, and Hs 578T). All three complexes (1–3) exhibited good IC50 values (6.81 to 16.87 μM for 24 h as seen from the MTS assay) results which indicated that these complexes were found to be potential anticancer agents against the TNBC cells.

scholarly journals Inhibition of Poly(ADP-Ribose) Polymerase by Nucleic Acid Metabolite 7-Methylguanine

Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 108-115 ◽  
Author(s):  
D. K. Nilov ◽  
V. I. Tararov ◽  
A. V. Kulikov ◽  
A. L. Zakharenko ◽  
I. V. Gushchina ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Breast Cancer Cells ◽  
Inhibitory Concentration ◽  
Chemotherapeutic Agents ◽  
Purine Derivatives ◽  
Acid Metabolite ◽  
Methyl Group ◽  
Ic50 Values ◽  
Chemotherapeutic Treatment ◽  
Parp 1

The ability of 7-methylguanine, a nucleic acid metabolite, to inhibit poly (ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose)polymerase-2 (PARP-2) has been identified in silico and studied experimentally.The amino group at position 2 and the methyl group at position 7 were shown to be important substituents for the efficient binding of purine derivatives to PARPs. The activity of both tested enzymes, PARP-1 and PARP-2, was suppressed by 7-methylguanine with IC50 values of 150 and 50 M, respectively. At the PARP inhibitory concentration, 7-methylguanine itself was not cytotoxic, but it was able to accelerate apoptotic death of BRCA1-deficient breast cancer cells induced by cisplatin and doxorubicin, the widely used DNA-damaging chemotherapeutic agents. 7-Methylguanine possesses attractive predictable pharmacokinetics and an adverse-effect profile and may be considered as a new additive to chemotherapeutic treatment.

scholarly journals Molecular insights into the inhibition of plasmepsins by HIV-1 protease inhibitors: Implications for antimalarial drug discovery

2021 ◽  
Author(s):  
Vandana Mishra ◽  
Ishan Rathore ◽  
Anuradha Deshmukh ◽  
Swati Patankar ◽  
Alla Gustchina ◽  
...  
Keyword(s):  
Protease Inhibitors ◽  
Drug Targets ◽  
Drug Repurposing ◽  
Binding Mode ◽  
Ic50 Values ◽  
Multiple Regions ◽  
Potential Drug Targets ◽  
Hiv 1 ◽  
Micromolar Range

Malaria is a deadly disease, and the worldwide emergence of drug resistance in the Plasmodium parasites demands the development of novel and potent antimalarials. HIV-1 protease inhibitors (HIV-1 PIs) alleviate the Plasmodium pathogenesis during malaria/HIV-1 co-infection plausibly by inhibiting vacuolar plasmepsins (PMs), the hemoglobin degrading proteases from P. falciparum. All five FDA-approved HIV-1 PIs tested against PMII exhibit the Ki values in the low micromolar range of which RTV and LPV display the highest inhibition activity. Both inhibitors impede in vitro growth of P. falciparum at low micromolar IC50 values. We report the first crystal structures of PMII complexed with RTV and LPV that reveal the binding mode and interactions of the inhibitors in the active site as well as elucidate the mechanism underlying their differential potency. The conformational flexibility of the P4 group in RTV allows it to explore multiple regions of the S4 pocket. The present study establishes vacuolar PMs as potential drug targets of HIV-1 PIs. The molecular details explaining the inhibitory mechanism of HIV-1 PIs might be crucial in designing novel and potent antimalarial analogs. This work strengthens the prospect of drug repurposing as an alternative strategy towards antimalarial treatments and provides an opportunity to tackle malaria and HIV-1 co-infection.

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