scholarly journals Modulating FOXO3 transcriptional activity by small, DBD-binding molecules

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Judith Hagenbuchner ◽  
Veronika Obsilova ◽  
Teresa Kaserer ◽  
Nora Kaiser ◽  
Bettina Rass ◽  
...  
Keyword(s):  
Small Molecules ◽  
Mammalian Cells ◽  
Transcriptional Activity ◽  
Pharmacophore Modeling ◽  
Docking Studies ◽  
Structural Basis ◽  
Dna Binding Domain ◽  
Transcriptional Program ◽  
Foxo Transcription Factors ◽  
Target Promoter

FOXO transcription factors are critical regulators of cell homeostasis and steer cell death, differentiation and longevity in mammalian cells. By combined pharmacophore-modeling-based in silico and fluorescence polarization-based screening we identified small molecules that physically interact with the DNA-binding domain (DBD) of FOXO3 and modulate the FOXO3 transcriptional program in human cells. The mode of interaction between compounds and the FOXO3-DBD was assessed via NMR spectroscopy and docking studies. We demonstrate that compounds S9 and its oxalate salt S9OX interfere with FOXO3 target promoter binding, gene transcription and modulate the physiologic program activated by FOXO3 in cancer cells. These small molecules prove the druggability of the FOXO-DBD and provide a structural basis for modulating these important homeostasis regulators in normal and malignant cells.

Cell-Specific Chemical Delivery Using a Selective Nitroreductase–Nitroaryl Pair

2018 ◽  
Author(s):  
Todd D. Gruber ◽  
Chithra Krishnamurthy ◽  
Jonathan B. Grimm ◽  
Michael R. Tadross ◽  
Laura M. Wysocki ◽  
...  
Keyword(s):  
Small Molecules ◽  
Mammalian Cells ◽  
Target Cells ◽  
Specific Chemical ◽  
E Coli ◽  
Enzyme Substrate ◽  
Cell Specificity ◽  
General Chemical ◽  
Increased Activity ◽  
Enzyme Variant

<p>The utility of<b> </b>small molecules to probe or perturb biological systems is limited by the lack of cell-specificity. ‘Masking’ the activity of small molecules using a general chemical modification and ‘unmasking’ it only within target cells could overcome this limitation. To this end, we have developed a selective enzyme–substrate pair consisting of engineered variants of <i>E. coli</i> nitroreductase (NTR) and a 2‑nitro-<i>N</i>-methylimidazolyl (NM) masking group. To discover and optimize this NTR–NM system, we synthesized a series of fluorogenic substrates containing different nitroaromatic masking groups, confirmed their stability in cells, and identified the best substrate for NTR. We then engineered the enzyme for improved activity in mammalian cells, ultimately yielding an enzyme variant (enhanced NTR, or eNTR) that possesses up to 100-fold increased activity over wild-type NTR. These improved NTR enzymes combined with the optimal NM masking group enable rapid, selective unmasking of dyes, indicators, and drugs to genetically defined populations of cells.</p>

Validation of TZD Scaffold as Potential ARIs: Pharmacophore Modeling, Atom-based 3D QSAR and Docking Studies

2017 ◽  
Vol 20 (4) ◽  
Author(s):  
Lalita Dahiya ◽  
Manoj Kumar Mahapatra ◽  
Ramandeep Kaur ◽  
Vipin Kumar ◽  
Manoj Kumar
Keyword(s):  
3D Qsar ◽  
Pharmacophore Modeling ◽  
Docking Studies

Pharmacophore Modeling and Docking Studies to Investigate Potential Leads for the Development of β -Secretase APP Cleavage Enzyme-1 (BACE-1) Inhibitors

2019 ◽  
Vol 16 (7) ◽  
pp. 775-784
Author(s):  
Richa Arya ◽  
Satya Prakash Gupta ◽  
Sarvesh Paliwal ◽  
Swapnil Sharma ◽  
Kirtika Madan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Medical Condition ◽  
Pharmacophore Model ◽  
Pharmacophore Modeling ◽  
Docking Studies ◽  
Pyridine Derivative ◽  
Cleavage Enzyme ◽  
Bace 1

Background: Alzheimer’s disease is a medical condition with detrimental brain health. It is majorly diagnosed in aging individuals plaque in β) characterized by accumulated Amyloidal beta (A 1 BACE) 1 secretase APP cleavage enzyme βneurological areas. The ) is the target of choice that can be exploited to find drugs against Alzheimer’s disease. Methods: A series of BACE-1 inhibitors with reported binding constant were considered for the development of a feature based pharmacophore model. Results: The good correlation coefficient (r=0.91) and RMSD of 0.93 was observed with 30 compounds in training set. The model was validated internally (r2test=0.76) as well as externally by Fischer validation. The pharmacophore based virtual screening retrieved compounds that were docked and biologically evaluated. Conclusion: The three structurally diverse molecules were tested by in-vitro method. The pyridine derivative with highest fit value (6.9) exhibited IC50 value of 2.70 µM and thus was found to be the most promising lead molecule as BACE-1 inhibitor.

IDENTIFICATION OF SELETIVE CLAUDIN CATION CHANNEL BLOCKERS

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S25-S26
Author(s):  
Jingjing Ma ◽  
Emma Wu ◽  
Ye Li ◽  
William Seibel ◽  
Le Shen ◽  
...  
Keyword(s):  
Small Molecules ◽  
Homology Model ◽  
Docking Studies ◽  
Channel Blockers ◽  
Binding Modes ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Dynamics Simulations ◽  
In Silico Models

Abstract Compromised epithelial barrier function is known to be associated with inflammatory bowel disease (IBD) and may contribute to disease development. One mechanism of barrier dysfunction is increased expression of paracellular tight junction ion and water channels formed by claudins. Claudin-2 and -15 are two such channels. We hypothesize that blocking these channels could be a viable therapeutic approach to treat diarrhea. In an effort to develop blockers of these channels, we turn to our previously developed and validated in silico models of claudin-15 (Samanta et al. 2018). We reasoned that compounds that can bind with the interior of claudin pores can limit paracellular water and ion flux. Thus, we used docking algorithms to search for putative small molecules that bind in the claudin-15 pore. AutoDock Vina was initially used to assess rigid docking using small compound databases. The small molecules were analyzed based on binding affinity to the pore and visualized using VMD for their potential blockage of the channel. Clusters of binding modes were identified based on the prominent interacting residues of the protein with the small molecules. We initially screened 10,500 compounds from within the UIC Centre for Drug Discovery and a cross-section of 10,000 compounds from the NCI open compound repository. This initial screen allowed us to identify 2 first-in-class selective claudin-15 blockers with efficacy in MDCK monolayers induced to express claudin-15 and in wildtype duodenum. Next, we screened the entire NCI open compound repository for additional molecules structurally related to our best initially identified molecule and this has allowed us to identify 13 additional molecules that increase TER of claudin-15 expressing MDCK monolayers by 90–160%. Additionally, these molecules possess similar structural components that will be collected in a fragment library and explored through molecular dynamics simulations. We also developed a claudin-2 homology model on which we are performing docking studies and in vitro measurements, which we expect will result in similar candidate ligands for blocking claudin-2. Our study will provide important insight into the role of claudin-dependent cation permeability in fundamental physiology, which we believe will lead to the utility of claudin blockers as a novel and much needed approach to treat diseases such as IBD.

Structural basis of the p53 DNA binding domain and PUMA complex

2021 ◽  
Vol 548 ◽  
pp. 39-46
Author(s):  
Chang Woo Han ◽  
Han Na Lee ◽  
Mi Suk Jeong ◽  
So Young Park ◽  
Se Bok Jang
Keyword(s):  
Dna Binding ◽  
Binding Domain ◽  
Structural Basis ◽  
Dna Binding Domain

scholarly journals Structural basis for proficient oxidized ribonucleotide insertion in double strand break repair

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joonas A. Jamsen ◽  
Akira Sassa ◽  
Lalith Perera ◽  
David D. Shock ◽  
William A. Beard ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Time Lapse ◽  
Strand Break ◽  
Structural Basis ◽  
End Joining ◽  
Strand Breaks ◽  
Nucleotide Pools ◽  
Nucleotide Insertion ◽  
Non Homologous End Joining

AbstractReactive oxygen species (ROS) oxidize cellular nucleotide pools and cause double strand breaks (DSBs). Non-homologous end-joining (NHEJ) attaches broken chromosomal ends together in mammalian cells. Ribonucleotide insertion by DNA polymerase (pol) μ prepares breaks for end-joining and this is required for successful NHEJ in vivo. We previously showed that pol μ lacks discrimination against oxidized dGTP (8-oxo-dGTP), that can lead to mutagenesis, cancer, aging and human disease. Here we reveal the structural basis for proficient oxidized ribonucleotide (8-oxo-rGTP) incorporation during DSB repair by pol μ. Time-lapse crystallography snapshots of structural intermediates during nucleotide insertion along with computational simulations reveal substrate, metal and side chain dynamics, that allow oxidized ribonucleotides to escape polymerase discrimination checkpoints. Abundant nucleotide pools, combined with inefficient sanitization and repair, implicate pol μ mediated oxidized ribonucleotide insertion as an emerging source of widespread persistent mutagenesis and genomic instability.

Tyrosine phosphorylation controls nuclear localization and transcriptional activity of Ssdp1 in mammalian cells

2008 ◽  
Vol 103 (6) ◽  
pp. 1856-1865 ◽  
Author(s):  
Ipsita Dey-Guha ◽  
Nasir Malik ◽  
Renaud Lesourne ◽  
Paul E. Love ◽  
Heiner Westphal
Keyword(s):  
Tyrosine Phosphorylation ◽  
Nuclear Localization ◽  
Mammalian Cells ◽  
Transcriptional Activity

scholarly journals GENETIC INVOLVEMENT OF INTERLEUKIN 4 FOR ASTHMA AND IDENTIFICATION OF POTENTIAL PHYTOCHEMICAL SCAFFOLD THROUGH MOLECULAR DOCKING STUDIES

2018 ◽  
Vol 10 (1) ◽  
pp. 43 ◽  
Author(s):  
S. Sarithamol ◽  
Divya V. ◽  
Sunitha V. R. ◽  
Suchitra Surendran ◽  
V. L. Pushpa ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Small Molecules ◽  
In Silico ◽  
Mutational Analysis ◽  
Chromosome Region ◽  
Specific Treatment ◽  
Docking Studies ◽  
Interleukin 4 ◽  
Receptor Interaction ◽  
Drug Candidates

Objective: Interleukin 4, an important cytokine, has the major role in the immunomodulatory responses associated with asthma. The present study focused on the involvement of single nucleotide polymorphism variation (SNP) of interleukin 4 (IL4) in the development of disease, asthma and designing small molecules for the inhibition of IL4 through in silico strategy.Methods: Identification of disease causing SNP will be a wise approach towards the phenotype specific treatment. A human origin deleterious no synonymous SNP of IL4 were found out in the chromosome region 5q31-q33 (rs199929962) (T/C). Proteins of the corresponding nucleotide variation were identified and were subjected to characterization studies for selecting the most appropriate one for further mutational analysis and molecular docking studies.Results: Influence of microbes on SNP variation of IL4 gene leading to asthma was found to be insignificant by metagenomic studies. Gene responsive drugs were identified through environmental factor analysis. The drug candidates including corticosteroids were subjected to protein interaction studies by in silico means. The pharmacophoric feature derived from drug receptor interaction was utilized for virtual screening on a dataset of anti-inflammatory phytomolecules. The scaffolds of ellagic acid and quercetin were identified as potential nonsteroidal entities which can shield the asthmatic activities.Conclusion: Developing small molecules using these scaffolds taking interleukin 4 as a target will be an adequate solution for steroid resistant asthma.

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