Search results for "Structure-Activity relationship"
showing 10 items of 743 documents
Identification of the Privileged Position in the Imidazo[1,2-a]pyridine Ring of Phosphonocarboxylates for Development of Rab Geranylgeranyl Transfera…
2017
Members of the Rab GTPase family are master regulators of vesicle trafficking. When disregulated, they are associated with a number of pathological states. The inhibition of RGGT, an enzyme responsible for post-translational geranylgeranylation of Rab GTPases represents one way to control the activity of these proteins. Because the number of molecules modulating RGGT is limited, we combined molecular modeling with biological assays to ascertain how modifications of phosphonocarboxylates, the first reported RGGT inhibitors, rationally improve understanding of their structure-activity relationship. We have identified the privileged position in the core scaffold of the imidazo[1,2-a]pyridine r…
Identification of noncovalent proteasome inhibitors with high selectivity for chymotrypsin-like activity by a multistep structure-based virtual scree…
2016
Noncovalent proteasome inhibitors introduce an alternative mechanism of inhibition to that of covalent inhibitors, e.g. carfilzomib, used in cancer therapy. A multistep hierarchical structure-based virtual screening (SBVS) of the 65,375 NCI lead-like compound library led to the identification of two compounds (9 and 28) which noncovalently inhibited the chymotrypsin-like (ChT-L) activity (Ki = 2.18 and 2.12 μM, respectively) with little or no effects on the other two major proteasome proteolytic activities, trypsin-like (T-L) and post-glutamyl peptide hydrolase (PGPH) activities. A subsequent hierarchical similarity search over the full NCI database with the most active tripeptide-based inh…
Anticancer properties of 4-thiazolidinone derivatives depend on peroxisome proliferator-activated receptor gamma (PPARγ)
2017
Peroxisome proliferator-activated receptors (PPARs) play an important role in numerous chronic diseases such as diabetes, obesity, atherosclerosis and cancer, and PPAR modulators are among the approved drugs and drug-candidates for their treatment. The aim of this study was to elucidate the involvement of PPARs in the mechanism of cytotoxic and pro-apoptotic action of novel anticancer 4-thiazolidinone derivatives (Les-2194, Les-3377, Les-3640) and approved 4-thiazolidinones (Rosiglitazone, Pioglitazone) towards the human squamous carcinoma (SCC-15) cell line. Experiments with 4-thiazaolidinone derivatives and PPAR-specific siRNA were conducted and PPARα, PPARβ and PPARγ mRNA expression was …
Bistacrine derivatives as new potent antimalarials
2016
Linking two tacrine molecules results in a tremendous increase of activity against Plasmodia in comparison to the monomer. This finding prompted the synthesis of a library of monomeric and dimeric tacrine derivatives in order to derive structure-activity relationships. The most active compounds towards chloroquine sensitive Plasmodium strain 3D7 and chloroquine resistant strain Dd2 show IC50 values in the nanomolar range of concentration, low cytotoxicity and target the cysteine protease falcipain-2, which is essential for parasite growth.
Permeating disciplines: Overcoming barriers between molecular simulations and classical structure-function approaches in biological ion transport
2017
Ion translocation across biological barriers is a fundamental requirement for life. In many cases, controlling this process-for example with neuroactive drugs-demands an understanding of rapid and reversible structural changes in membrane-embedded proteins, including ion channels and transporters. Classical approaches to electrophysiology and structural biology have provided valuable insights into several such proteins over macroscopic, often discontinuous scales of space and time. Integrating these observations into meaningful mechanistic models now relies increasingly on computational methods, particularly molecular dynamics simulations, while surfacing important challenges in data manage…
A Simple Method to Predict Blood-Brain Barrier Permeability of Drug- Like Compounds Using Classification Trees
2017
Background: To know the ability of a compound to penetrate the blood-brain barrier (BBB) is a challenging task; despite the numerous efforts realized to predict/measure BBB passage, they still have several drawbacks. Methods: The prediction of the permeability through the BBB is carried out using classification trees. A large data set of 497 compounds (recently published) is selected to develop the tree model. Results: The best model shows an accuracy higher than 87.6% for training set; the model was also validated using 10-fold cross-validation procedure and through a test set achieving accuracy values of 86.1% and 87.9%, correspondingly. We give a brief explanation, in structural terms, o…
Recent advances on CDK inhibitors: An insight by means of in silico methods
2017
The cyclin dependent kinases (CDKs) are a small family of serine/threonine protein kinases that can act as a potential therapeutic target in several proliferative diseases, including cancer. This short review is a survey on the more recent research progresses in the field achieved by using in silico methods. All the "armamentarium" available to the medicinal chemists (docking protocols and molecular dynamics, fragment-based, de novo design, virtual screening, and QSAR) has been employed to the discovery of new, potent, and selective inhibitors of cyclin dependent kinases. The results cited herein can be useful to understand the nature of the inhibitor-target interactions, and furnish an ins…
Molecular topology: A new strategy for antimicrobial resistance control
2017
The control of antimicrobial resistance (AMR) seems to have come to an impasse. The use and abuse of antibacterial drugs has had major consequences on the genetic mutability of both pathogenic and nonpathogenic microorganisms, leading to the development of new highly resistant strains. Because of the complexity of this situation, an in silico strategy based on QSAR molecular topology was devised to identify synthetic molecules as antimicrobial agents not susceptible to one or several mechanisms of resistance such as: biofilms formation (BF), ionophore (IA) activity, epimerase (EI) activity or SOS system (RecA inhibition). After selecting a group of 19 compounds, five of them showed signific…
The RNA methyltransferase Dnmt2 methylates DNA in the structural context of a tRNA
2016
The amino acid sequence of Dnmt2 is very similar to the catalytic domains of bacterial and eukaryotic DNA-(cytosine 5)-methyltransferases, but it efficiently catalyzes tRNA methylation, while its DNA methyltransferase activity is the subject of controversial reports with rates varying between zero and very weak. By using composite nucleic acid molecules as substrates, we surprisingly found that DNA fragments, when presented as covalent DNA-RNA hybrids in the structural context of a tRNA, can be more efficiently methylated than the corresponding natural tRNA substrate. Furthermore, by stepwise development of tRNAAsp, we showed that this natural Dnmt2 substrate could be engineered to employ R…
RepeatsDB 2.0: improved annotation, classification, search and visualization of repeat protein structures
2017
RepeatsDB 2.0 (URL: http://repeatsdb.bio.unipd.it/) is an update of the database of annotated tandem repeat protein structures. Repeat proteins are a widespread class of non-globular proteins carrying heterogeneous functions involved in several diseases. Here we provide a new version of RepeatsDB with an improved classification schema including high quality annotations for ∼5400 protein structures. RepeatsDB 2.0 features information on start and end positions for the repeat regions and units for all entries. The extensive growth of repeat unit characterization was possible by applying the novel ReUPred annotation method over the entire Protein Data Bank, with data quality is guaranteed by a…